Tiêm Botulinum Toxin Trong Thực Hành Thẩm Mỹ (Tập 2): Giải Phẫu Chức Năng Và Kỹ Thuật Tiêm

14.  cosmetic uses of botulinum toxin a in the mid face
193
is hypertrophic and hyperkinetic from constant squinting (see also
Tamura’s bunny line patterns).
Outcomes (Results) When Treating Nasoglabellar Lines
(see Appendix 5)
Eliminating nasoglabellar lines along with glabellar frown lines gives
an individual a relaxed, youthful appearance. When the nasoglabellar
lines are not treated and the glabellar frown lines are, nasoglabellar
lines in the presence of a smooth glabella produce an exceptionally
unsightly effect (Figures 14.2 and 14.9).
Tamura et al.19 found that they could successfully treat approxi­
mately 40% of their patients with nasoglabellar lines by injecting
them with 3 U of OnaBTX-A on either side of the nasal side wall
into the belly of the transverse nasalis (Figure 14.10). The other 60%
of the patients in their study had persistent bunny lines that exhib­
ited different linear patterns along the proximal and distal nasal
bridge. They found that to further diminish these persistent bunny
lines an additional 2 U of OnaBTX-A needed to be injected at dif­
ferent locations along either side of the nasal bridge according to the
three different patterns they identified. They named the recalcitrant
bunny lines according to their anatomic location as the nasoalar
rhytides, nasoorbicular rhytides, and nasociliary rhytides (Figures
14.1 and 14.11). The additional OnaBTX-A treatments were given
during the first follow-up visit, 4 weeks after the initial treatment
3
2
1
Figure 14.8  The blue dot (•) marks the point at which injections should be placed
when treating the compressor naris (transverse nasalis) to avoid inadvertently
weakening the levators of the central upper lip and injuring the angular neurovas­
cular structures. 1, LLSAN; 2, LLS; 3, transverse nasalis. See Chapter 12, Figures
12.1 and 12.2.
(a)
(b)
Figure 14.9  Note the presence of glabellar and nasoglabellar “bunny lines” before (a) and the compensatory contractions of the transverse nasalis 3 weeks after (b) an
OnaBTX-A treatment of only glabellar frown lines. Patient insisted on not having her bunny lines treated.
(a)
(b)
4
3
4
Figure 14.10  A 52-year-old patient frowning (a) before and (b) 2 weeks after a treatment with OnaBTX-A of both the glabellar (4 units into the procerus) and nasoglabellar
(total of 7 units) lines. Note the stronger and deeper lines on the left which required an extra unit of OnaBTX-A and the diminished “bunny lines.”

Botulinum Toxins in Clinical Aesthetic Practice
194
with OnaBTX-A. There were approximately 30% of the patients who
had persistent wrinkling at the root of the nose, which extended
superiorly toward the medial margin of the eyebrow and glabella
caused by the contraction of the orbital orbicularis oculi adjacent to
the ciliary arch, so they were identified as having nasociliary rhyt­
ides (Figures 14.1a, c and 14.11). Another 30% of the patients had
persistent wrinkling of the root of the nose owing to contraction of
the nasal portion of the orbital orbicularis oculi, so these patients
were identified as having nasoorbicular rhytides (Figures 14.1b, and
d and 14.11). The third pattern, identified as persistent naso-alar
wrinkles, occurred in both of the above subgroups and were felt
to be the result of the contraction of the alar portion of the LLSAN
(Figures 14.1b–d and 14.11). Each area of persistent wrinkling was
produced by unaffected fibers of the underlying muscles after a
standard treatment with OnaBTX-A, which required the additional
2 U of OnaBTX-A on either side of the nasal bridge to completely
eliminate any residual nasoglabellar “bunny lines” (Figures 14.12
and 14.13).19
However, patients who recruit cheek and submalar skin and elevate
it toward the nasal radix forming corrugations of skin along the lateral
1
2
3
4
5
(a)
(b)
1
2
3
4
5
Figure 14.11  (a, b) Standard injection point for transverse nasalis: blue dot (•). Note the additional injections sites to diminish persistent nasoglabellar lines: red dot (•) for
nasociliary rhytides; green dot (•) for nasoorbicular rhytides; purple dot (•) for nasoalar rhytides.
(a)
(b)
2
2
4
8
4
Figure 14.12  A 45-year-old patient frowning (a) before and (b) 3 weeks after a treatment with OnaBTX-A of both the horizontal glabellar and oblique nasoglabellar
lines. The horizontal line across the root of the nose produced by the procerus were treated with 8 units of OnaBTX-A; the nasociliary lines were treated with 2 units of
OnaBTX-A on either side of the nasal root and the nasoorbicular lines were treated with 4 units of OnaBTX-A on either side of the nasal bridge. Note the complete elimina­
tion of the “bunny lines.”

14.  cosmetic uses of botulinum toxin a in the mid face
195
aspect of the proximal nose will not be helped by OnaBTX-A injec­
tions (Figure 14.4). Injections of OnaBTX-A will diminish only those
rhytides that are formed by the contraction of the transverse nasalis
and contributing ancillary muscle fibers, such as the medial portion of
the orbital orbicularis oculi, alar portion of the LLSAN, and possibly
an anomalus nasi when present (Figures 14.3, 14.6, 14.12, and 14.13).
Usually, one can expect the effect of an OnaBTX-A treatment of naso­
glabellar lines to last at least 3–4 months, or however long the glabellar
frown lines remain effaced. In patients who previously had undergone
a rhinoplasty, the results may be somewhat less than expected.17–18,20,21
Complications (Adverse Sequelae) When Treating Nasoglabellar
Lines (See Appendix 6)
Injecting OnaBTX-A too deeply and low along the nasal sidewalls
and into the nasofacial sulcus will allow it to diffuse into the upper
lip levators (i.e., levator labii superioris alaeque nasi and levator labii
superioris), since they both originate along the medial aspect of the
malar prominence. If either of these levators is affected, the outcome
can be an asymmetric smile and even ptosis of the upper lip, resulting
in sphincter incompetence and functional difficulties with speaking,
eating, and drinking.
Also, if the medial palpebral orbicularis oculi is weakened as the
result of the unintended diffusion of OnaBTX-A, a diminution in the
action of the lacrimal pump can occur, causing epiphora (excessive
tearing) (see Chapter 13).21 Diplopia also can result if the medial rec­
tus is weakened by the inadvertent spread of OnaBTX-A caused by
overzealous dosing or incorrect placement of the injection. Vigorous
massage to the area after the injection of OnaBTX-A can cause it to
spread beyond the targeted area and produce the same untoward
adverse results, even if dosing is appropriate and the injection tech­
nique is flawless. There is no antidote for any of these untoward post-
treatment sequelae, and the patient is obligated to endure them until
the effects of the OnaBTX-A remit. In the meantime, consultation
with an ophthalmologist to help the patient cope with these alarming
ocular problems is advisable.
It is important also to keep in mind that the angular artery and
vein sit in the nasofacial angle and injections placed too low along
the nasal sidewall and too deeply into the skin can result in an intra­
vascular injection of the OnaBTX-A or injury to one of the vessels
causing either ecchymoses (vein) or hematoma (artery). Therefore,
intradermal or superficial subcutaneous placement of the needle tip
is all that is necessary when injecting this area with a BoNT (Figure
14.7). There have been no reports of any adverse events from an intra­
vascular injection of OnaBTX-A when less than 10 U is injected.
Figures 14.14 through 14.19 are additional examples of different
patients treated with OnaBTX-A for nasoglabellar lines.
Treatment Implications When Injecting Nasoglabellar Lines

1. Squinting will reveal the presence or absence of naturally occur­
ring nasoglabellar lines in some individuals and are identified
as “bunny lines.” They should be elicited and recognized before
treating glabellar frown lines with OnaBTX-A.
6
4
6
4
(a)
6
(b)
Figure 14.13  This 49-year-old patient is shown (a) before and (b) 3 weeks after an OnaBTX-A treatment. Note: Glabellar treatment units are shown in white, and the naso­
glabellar units in black.
(a)
(b)
2
2
3
3
5
Figure 14.14  A 59-year-old patient frowning (a) before and (b) 3 weeks after a treatment with OnaBTX-A of both the glabellar and nasoglabellar lines. Note the diminished
“bunny lines.”

Botulinum Toxins in Clinical Aesthetic Practice
196

2. When nasoglabellar lines are produced as a result of compensa­
tory contraction of the transverse nasalis after an OnaBTX-A
treatment, they are referred to as the “BOTOX® sign.”

3. Treat vertical nasoglabellar frown lines (i.e., those produced by
the contraction of the transverse nasalis) along with horizontal
glabellar frown lines (i.e., those produced by the contraction of
the procerus) during the same treatment session.

4. Injections of OnaBTX-A should be performed intradermally or
subcutaneously into the lateral aspect of the nasal bridge and
radix.

5. Injections given too low and too deeply into the nasofacial sulcus
may result in ecchymoses, hematoma, an asymmetric smile, or
even upper lip ptosis and upper lip incompetence and functional
difficulties of the sphincteric action of the mouth.
(a)
(b)
4
4
4
Figure 14.15  A 55-year-old patient frowning (a) before and (b) 4 weeks after a treatment with OnaBTX-A of both the glabellar and nasoglabellar lines (nasoalar). Note the
diminished “bunny lines.”
6
4
6
2
3
2
3
3
3
(a)
(b)
Figure 14.16  This 52-year-old patient has nasociliary, naso-orbicular, and naso-alar nasoglabellar lines. She is shown here (a) before and (b) 8 days after an OnaBTX-A
treatment. Note: Glabellar treatment units are shown in white, and the nasoglabellar units in black.
6
3
4
2
3
6
(a)
(b)
Figure 14.17  This 67-year-old patient is shown (a) before and (b) 2 weeks after an OnaBTX-A treatment. Note: Glabellar treatment units are shown in white, and the naso­
glabellar units in black.

14.  cosmetic uses of botulinum toxin a in the mid face
197

6. Additional units of OnaBTX-A may be needed along the lat­
eral aspect of the nasal radix and the proximal and distal nasal
bridge in different patterns to efface all the nasoglabellar lines
in ~60% of patients.

7. Patients with inelastic, lax skin who squint excessively may pro­
duce nasoglabellar lines that cannot be reduced by OnaBTX-A
injections.
NASAL FLARE
Introduction: Problem Assessment and Patient Selection
Noses come in different forms and shapes (Figure 14.20). The size,
shape, and proportions of the nose contribute to an individual’s beauty
or handsomeness, by virtue of its position in the center of the face. A
broad classification of noses is based on the shape of the nasal or alar
base. The leptorrhine or long and narrow nose is found on Causcasian
3
3
6
2
2
6
6
(a)
(b)
Figure 14.18  A 66-year-old patient frowning (a) before and (b) 1 week after a treatment with OnaBTX-A of both the glabellar and nasoglabellar lines (nasoorbicular and nasoa­
lar). Note the diminished “bunny lines.” Glabellar treatment units are shown in white, and the nasoglabellar units in black.
6
4
4
4
3
3
6
(a)
(b)
Figure 14.19  This 80-year-old patient is seen before (a) and 3 months after (b) an OnaBTX-A treatment of nasoglabellar or “bunny” lines. Note that the glabella was treated
simultaneously. Glabellar treatment units are shown in white, and the nasoglabellar units in black.
(a)
(b)
(c)
(d)
(e)
(f)
(g)
Figure 14.20  Different types and variations in nasal profile: (a) Grecian; (b) Roman; (c) Nordic; (d) Middle Eastern/Northern African; (e) Asian-Mongolian; (f) Asian-
Indian; (g) sub-Saharan African.

Botulinum Toxins in Clinical Aesthetic Practice
198
faces, the mesorrhine or somewhat flat nose of medium length and
width is found on the faces of the Oriental races and the platyrrhine or
short, broad and flat nose is found on the faces of the Negroid races22
(Figure 14.21). An individual’s nose is one of the most distinguishing
anatomical structures that identifies a person’s race and differenti­
ates one’s ethnic group from another.23 It is the shape of the nose that
is a person’s signature indicating one’s race, ethnicity, age, and sex.
Anthropometric differences also vary with age, sex, and ethnic and
racial background. However, in this age of globalization with unre­
stricted travel and all-inclusive social exchanges, interracial mingling
resulting in interindividual variations, has now become considerably
more extensive among the different ethnic groups and races.23–27 For
example, in the West, particularly in the Americas, the “mestizo”
population originates from three predominant races: the Indigenous
Indian, the European Caucasian, and the African Negroid popula­
tions. Latin American mestizos do not have a specific phenotypical
racial pattern, and their predominant facial features vary depend­
ing on the geographic zone from which they originate. People from
Mexico, Peru, Bolivia, and many Central American countries exhibit
stronger Indigenous Indian facial characteristics, whereas people from
Argentina and Chile exhibit stronger European facial characteristics.
People from Brazil, the Caribbean islands, and the coasts of Colombia
and Venezuela exhibit a stronger African influence in their facial fea­
tures. The same can be said of other cultures and ethnic groups in dif­
ferent parts of the East where the influences of globalization also have
taken place (see Chapter 17, by Kyle Seo).
Mestizo facial charactersitics vary widely from the traditional
western European Caucasian face, even though they are genotypi­
cally related. The mestizo face tends to be broad with thick skin and
a nose that looks small, undefined, bulbous, and slightly flattened.
The underlying structural support of the mestizo or mesorrhine
nose is less robust than a leptorrhine nose: bones are small and wide,
although many have a deep radix and a small hump. Cartilaginous
structures are thin and weak with a wide cartilaginous vault. Nasal tip
support is weak because of a weak caudal septum, small nasal spine,
and unsupportive alar cartilages. Externally, the mestizo mesorrhine
nose can have a wide nasal bridge, low radix, wide nasal base, short
columella, acute nasolabial angle, and nostrils that tend to have a more
flaring and horizontal shape (Figure. 14.22).25 It is not surprising that
the Asian messorrhine nose also shares similar characteristics as the
Mestizo mesorrhine nose, since more than 30,000 years ago people
with Asian and Mongolian features crossed the Bering Straits and
formed the different indigenous tribes that inhabited the regions of the
New World when the Spanish and Portuguese sailed to the Americas
in the fifteenth and sixteenth centuries.22,25
There are some individuals who, either naturally or when they
are under physical or emotional stress, flare their nostrils and
widen their nasal aperture repeatedly as they inspire. Noticeable
movement of the nostrils with forced inspiration can impart to the
casual observer a negative attitude, which may include anger, fear,
exhaustion, concern, disapproval, or personal distress. For some,
active dilation of the nostrils also occurs while they are speak­
ing, smiling, laughing, or expressing an emotion (Figures 14.23
and 14.24). This unwanted predilection for inadvertently flaring
the nostrils occurs more frequently in those who possess a broad
nasal bridge with a wide nasal alar base. It can also occur in those
individuals with a more leptorrhine shaped nose (Figures 14.23
and 14.24). Generally, however, it is those individuals with a more
mesorrhine or platyrrhine shaped nose, whose alar lobules visibly
contract uncontrollably during inspiration and facial animation
Leptorrhine
Mesorrhine
Platyrrhine
Figure 14.21  Examples of different nostril shapes seen frontally and from slightly below: leptorrhine (long and narrow), mesorrhine (medium), and platyrrhine (broad
and flat).

14.  cosmetic uses of botulinum toxin a in the mid face
199
who seek relief from these embarrassing involuntary movements of
their noses. This unconscious flaring of the nostrils occurs in some
individuals because the overall mesorrhine and platyrrhine shape
of their noses predisposes their alar musculature (i.e., dilator nares
and levator labii superioris alaque nasi) to be more developed and
active, because they are larger and stronger. These muscles also will
allow such individuals to dilate their nostrils deliberately as well as
involuntarily. Consequently, their noses possess a variety of addi­
tional nasal movements more so than noses of a leptorrhine shape
and form.27 For individuals who are troubled with involuntary nasal
flaring, injections of OnaBTX-A may diminish this embarrassing,
idiosyncratic synkinesis.
Functional Anatomy (See Appendix 2) of a Nasal Flare
Nasal flaring is the result of the involuntary contraction of the muscles
of the nasal lobules, causing the alae nasi to dilate repeatedly during
inspiration and facial animation, particularly while eating, drinking,
speaking, laughing, and smiling9,10 (Figures 14.23 and 14.24).
Before commencing with a decscription of nasal musculature, it
is important for the reader to understand that there are significant
inconsistencies, contradictions, and even inaccuracies in nomencla­
ture of the different nasal muscles, depending on the date of a par­
ticular study and the prevailing terminology in use at the time of the
publication. The age, race, and ethnic origins of the subjects studied
and whether a given citation is an anatomic versus a surgical study
(a)
(b)
Figure 14.22  (a, b) A “Mestizo nose” has a wide nasal bridge, low radix, wide nasal base, short columella, acute nasolabial angle, and nostrils that are horizontal in shape
and flare more readily.
(a)
(b)
Figure 14.24  (a, b) This 72-year-old has a horizontal upper lip crease and actively dilates her nostrils when she smiles.
(a)
(b)
Figure 14.23  (a, b) This 63-year-old patient flares her nostrils and curls the upper lip forming a transverse upper lip crease with smiling. Note the downward rotation of the
nasal tip with nostril flaring. Note the posterior gummy show and the difference between this older patient and the younger one of Figure 14.30.

Botulinum Toxins in Clinical Aesthetic Practice
200
all have some bearing on the names of the muscles identified and
described. More importantly, not all muscles will be present in all
individuals, and interindividual variation may be substantial for those
muscles which are present, depending on the age, sex, race, and ethnic
background of the study subjects.12,28,29 It is even more confounding
when either anatomic or physiologic criteria are emphasized in a given
study. Consequently, comparative referencing can lead to some mis­
interpretation and confusion when defining the three-dimensional
functional anatomy of the nose.12,13
The nose, even more so than the ear, is a distinctively three-dimen­
sional structure that projects off the anterior surface of the face. The
mimetic muscles of the upper face can visibly function both as sepa­
rate and distinct muscles and as interdependent grouped agonists or
antagonists, and thus contract synergistically as co-depressors (cor­
rugator supercilii, depressor supercilii, procerus, orbicularis oculi)
or independently as a levator (frontalis). However, only a few if any
of the mimetic muscles of the nose can function independently from
one another, but generally function synergistically during respiration,
phonation, and expression of an emotion in a noncompetitive, com­
plementary manner as compressors and dilators.12 The nasal muscles
possess different directional movements needed to maintain a patent
passageway for air, and to sustain a functional external and inter­
nal nasal valve for unobstructed breathing through the nostrils.30 In
addition, the nose has the unique ability to assist in the formation of
distinctive sounds as when one speaks, hums, or sings. If the normal
passage of air through the nasal vault is compromised in the slightest
amount, for example, because of a negligible deviation in the nasal
cartilagenous supporting structures or even because of edematous
nasal mucosa and turbinate hypertrophy caused by seasonal allergies
or an upper respiratory ailment, normal nasal muscle movements can
be altered. The result is an impairment of the nasal airway patency, an
increase in air flow resistance and an interference with one’s ability
to resonate air and clearly enunciate words or sing a tune. In addi­
tion, the overall appearance of one who is not feeling well can be
easily identified as one who “looks sick,” conspicuously expressed by
the involuntary and voluntary writhing movements of one’s mimetic
facial muscles, including the muscles of the nose. Therefore, the dif­
ferent nasal muscles must be appreciated for their divergent move­
ments functioning in a unified manner that are complementary to one
another. They maintain the integrity and consistency of inspiration
and expiration, as well as the unique activities of animation, verbal
and non-verbal communication.
The musculature of the non-cartilaginous portion of the alar lobule
contains two similarly functioning identifiable muscles that comple­
ment each other: the alar nasalis, also called the “posterior dilator
naris,” which is an extension of the more superiorly positioned trans­
verse nasalis, and the “anterior dilator naris” (Figure 14.25). In live or
cadaveric dissections, it is usually difficult to separate completely the
individual fibers of the posterior from the anterior dilator nares.29
The posterior dilator naris originates from the maxilla just above
the lateral incisor and canine teeth, slightly lateral to the bony ori­
gin of the depressor nasi septi and medial to the bony attachment
of the transverse nasalis, with which it partially merges (hence its
other name, alar nasalis) under the nasolabial fold (Figure 14.25).
The muscle fibers of the alar nasalis or posterior dilator naris travel
superiorly and anteriorly to insert into (a) the skin of the alar lob­
ule above the posterior circumference of the lateral crus of the
greater nasal cartilage (also known as the lower lateral cartilage),
(b) the accessory alar (sesamoid) cartilages in the hinge area, and
(c) the alar facial crease or groove at the margin of the nasal apera­
ture. It also inserts into the posterior part of the mobile septum
Figure 14.26).14 The alar nasalis also contributes to the formation
of the upper ridge of the philtrum and nostril sill (Figure 14.26).
Laterally, alar fibers of the posterior dilator naris interdigitate with
muscle fibers of the LLSAN and LLS. Medially, fibers of the alar
nasalis (i.e., posterior dilator naris) also interdigitate with muscle
fibers of the “anterior dilator naris” and the depressor septi nasi
(Figure 14.26). The posterior dilator naris draws the hinge area of
the ala laterally, and it can move the ala and the posterior part of
the columella downward, thereby assisting in elongating the nose
and widening the nasal aperture.
The anterior dilator naris is a fan-like muscle that originates from
the upper edge of the lower lateral cartilage in front of the alar nasalis
(posterior dilator naris) and the caudal margin of the lateral crus of the
lower lateral cartilage (Figure 14.25). It encircles the naris occupying
most of the lateral wall of the external nose (alar lobule) that lacks carti­
laginous support and interdigitates with the compressor narium minor
when it is present in the nasal dome13 (Figure 14.25). The anterior dila­
tor naris inserts into the rim of the lateral alar skin and nasal spine. Its
muscle fibers are arranged in a typical crisscross pattern similar to the
intrinsic muscles of the tongue.29 The primary function of the anterior
dilator naris is to stabilize this most flaccid portion of the lateral nasal
wall, assist in dilating the nostrils and prevent the ala nasi from col­
lapsing, especially during inspiration, thereby maintaining the com­
petency of the external nasal valve.9,10,14–17 However, it is the primary
muscle responsible in causing nasal flaring, which results in an increase
in nostril diameter and widening of the nasal vestibule.
Ducut and colleagues found in their cadaver dissection study of
Asian noses that there was a significant difference in the characteristics
of some nasal muscles which have a direct effect on the alar lobule and
nostril shape.27 The more horizontally shaped nostrils (of mesorrhine or
1
2
3
4
5
6
7
8
9
10
Figure 14.25  The non-cartilaginous portion of the alar lobule contains the alar
nasalis (also called the “posterior dilator naris”), an extension of the transverse
nasalis, and the anterior dilator naris. The muscles complement one another in
function. The compressor narium minor (when present) arises from the interme­
diate crus of the lower lateral cartilage, interdigitates with some muscle fibers of
the anterior dilator naris and inserts into the skin of the nasal dome near the mar­
gin of the nostrils and travels vertically down the columella to insert into the nasal
spine. When present, the “dilator apicis nasi” (also called the “small dilator muscle
of the nose”) is found attached to the lateral crus of the lower lateral cartilage and
encircles the distal lobule tip and nasal dome. 1, procerus; 2, depressor supercilii;
3, anomalus nasi; 4, transverse nasalis; 5, levator labii superioris alaeque nasi and
levator alae nasi; 6, anterior dilator naris; 7, compressor narium minor; 8, posterior
dilator naris (alar nasalis); 9, depressor septi; 10, orbicularis oris.

14.  cosmetic uses of botulinum toxin a in the mid face
201
platyrrhine noses) have larger and more developed anterior and posterior
dilator nares and depressor septi nasi than those of a more vertical leptor­
rhine nose.27 In fact, in horizontally shaped nostrils the insertion of the
posterior dilator naris extended to the midpoint between the alar base and
the nasal tip, whereas the posterior dilator naris of a vertically shaped nose
was limited to the alar base. The origin of the anterior dilator naris was
also easily identified in horizontally shaped nostrils as emerging from the
upper lateral cartilage and inserting into the caudal margin of the lower
lateral crus and alar lobular skin, whereas the anterior dilator naris of the
more vertically oriented nostrils was even difficult to identify. The ante­
rior dilator naris is the primary dilator of the nose, widening the ala as
it contracts. Contraction of the posterior dilator naris on the other hand
draws the ala and the posterior aspect of the columella downward, which
also widens the nasal aperture and can elongate the nose. Hyperkinetic
anterior and posterior dilator nares in mesorrhine and platyrrhine noses
tend to maintain the nostrils in an enlarged and widened state by con­
stantly pulling them downward and pushing them outward.27
In addition, Ducut et al. found that in the horizontally shaped nostrils
of mesorrhine and platyrrhine noses, the depressor septi nasi was more
developed and prominently attached to the footplate of the medial crus
of the lower lateral cartilage, extending and inserting into the columella,
the membranous septum and the skin of the columellar and medial nasal
vestibule. This anatomical configuration permits the depressor septi nasi
to pull in a downward direction the columella, the tip of the nose and
the dorsal border of the nostril. On the other hand, in vertically shaped
nostrils of leptorrhine noses, they found that the muscle attachment of
the depressor septi nasi barely reached the footplate of the medial crus or
it terminated just into the skin of the columellar base.27
Isometric contraction of the posterior dilator naris (alar nasalis) is
initiated with inspiration, and its dilator effect stabilizes the airway
lumen and maintains a fine control of air flow resistance by preventing
the sidewalls of the internal nasal valve from collapsing. Furthermore,
it was this muscle, the posterior dilator naris (alar nasalis), that Ducut
et al. surgically severed at its attachment to reduce the alar flare and
create a more vertically directed nostril.27 With the reduced dilating
effect and lateral pull of the posterior dilator naris, the alar lobule
shifted medially, producing a more leptorrhine shape to the previ­
ously mesorrhine or platyrrhine shaped nose.26 It is possible to pro­
duce a similar effect with a less invasive “chemical myotomy” using
OnaBTX-A injected into the appropriate areas of the nose of a properly
selected patient (Figure 14.27).
A secondary dilator of the nares is the medial alar portion of the
LLSAN also known as the levator alae nasi. The LLSAN originates
from the upper part of the frontal process of the maxilla and travels
downward obliquely and laterally, dividing into medial and lateral slips
of muscle. The medial fascicles of the LLSAN continue down along the
(a)
(b)
Nasal bones
Upper lateral cartilage
Nasal septal cartilage
Columella
Nasal septal cartilage
Lateral crus
Middle crus
Minor alar
cartilages
Lower lateral cartilage or major alar cartilage
6
1
2
3
4
5
Figure 14.26  (a) The external surface and skeletal anatomy of the nose: 1, nasal root (frontal bone); 2, nasal bridge (nasal bone); 3, ala; 4, naris; 5, philtrum; 6, alar nasalis.
(b) The cartilages and muscle origins of the nose. The alar nasalis (posterior dilator naris) originates from the maxilla and inserts in the skin of the alar lobule above the
posterior edge of the lateral crus of the lower lateral cartilage, accessory (sesamoid) alar cartilages, and the alar facial crease, and into the upper ridge of the philtrum.
Laterally it interdigitates with the levator labii superioris alaeque nasi and the levator labii superioris. Medially it interdigitates with the depressor septi nasi and the anterior
dilator naris.

Botulinum Toxins in Clinical Aesthetic Practice
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nasal sidewall and attach into the perichondrium of the lateral crus of
the lower lateral cartilage and insert into the overlying skin. In some
individuals, the levator alae nasi pulls the lateral crus superiorly dis­
placing the circumalar furrow laterally and modifying its curvature. It
also assists in dilating the nostrils. Because the levator alae nasi at times
can function together with the nasal tip muscle fibers of the depressor
septi nasi to retract the tip of the nose and help dilate the nostrils, both
muscles are considered secondary nasal dilators, but they have little or
no direct influence on the external nasal valve31 (see below).
In addition to the standard nasal musculature discussed above,
there are different accessory muscles of the nose which are not always
found in all people. The presence of these accessory muscles varies
widely between individuals, and their muscle function depends on the
age, sex, race, and ethnic background of a person and the size and
shape of his or her nose.9
The “anterior dilator naris,” at times has been misleadingly associated
with the “dilator apicis nasi” or the “small dilator muscle of the nose”14
(Figure 14.26). This very small muscle, like the anterior dilator naris,
is also found attached to the lateral crus of the lower lateral cartilage,
hence the confused association. However, in most reports, the apicis
nasi is not always present or identifiable and frequently considered too
small to be functionally significant.12,13 When present, however, the dila­
tor apicis nasi was found to encircle the distal part of the nose and lobule
tip, allowing the nasal tip to have barely perceptible circular movements
that are concentric or convergent and eccentric or divergent. Since sub­
tle expressions of pleasure and friendliness can be detected by involun­
tary circular movements of the nasal tip, these circular movements have
been attributed to the contractions of the apicis nasi.9,13,16,17,29
In contradistinction, expressions of displeasure, dislike, and aver­
sion are seen as vertical movements of the nasal tip. These vertical
movements can be attributed to yet another small muscle not always
present in the vicinity of the nasal tip called the compressor narium
minor (Figure 14.25). It arises from the intermediate crus of the lower
lateral cartilage and also interdigitates with some muscle fibers of the
anterior dilator naris. It inserts into the skin of the dome of the nose
near the margin of the nostrils and travels vertically down the colu­
mella to insert into the nasal spine. From the anatomical position and
location of its fibers, this muscle is thought to be able to contract con­
centrically and slightly compress and narrow the nasal aperture.9,12–14
Dilution (See Appendix 3) When Treating a Nasal Flare
Moderate diffusion of OnaBTX-A can be advantageous when treating
the lower dilators of the nose. Therefore, reconstituting a 100 U vial of
OnaBTX-A with 1–2.5 mL of normal saline to inject into this area is
acceptable.
Dosing: How to Correct the Problem (See Appendix 4), (What to
Do and What Not to Do) When Treating a Nasal Flare
Treat the patient in the sitting or semireclined position with subcuta­
neous injections of 2–3 U of OnaBTX-A at each injection point into
the center of each ala nasi equidistant from the alar groove and rim,
along the lateral fibers of the alar nasalis (posterior dilator naris) and
anterior dilator naris for a total of 4–10 U. This will weaken invol­
untary muscle contractions of the nostrils.3,32 Such results can be
useful in ethnic groups who possess a mesorrhine or platyrrhine
shaped nose with the characteristic broad nasal bridge and wide alar
base that flares easily because of hyperkinetic dilator nares (anterior
and posterior). Only those patients who can deliberately and actively
flare their nostrils are candidates for OnaBTX-A injections in this
area (Figure 14.27). However, the physician injector should always
be aware of the possible differences in strength and activity between
the anterior and posterior dilator nares when treating a person with
a platyrrhine shaped nose as opposed to someone with a mesorrhine
or leptorrhine shaped nose. When well selected, obvious candidates
do not experience a substantial improvement after a treatment with
OnaBTX-A, the physician should reassess the appropriateness of the
placement of the injections. Modification in technique, injection loca­
tion, and unit dosing might be necessary, depending on which dilator
muscle or muscles are more influential on that particular patient’s
nasal flare: the anterior or posterior dilator naris, the levator alae nasi
(i.e., the medial alar portion of the LLSAN), or the depressor septi
nasi. Injecting any one or all of these muscles at varying low doses
will have a positive influence in diminishing an involuntary, dynamic
nasal flare and reducing a horizontally oriented nostril aperture to a
more vertically oriented one. Patients of African, Latino, and Asian
descent or other individuals with either a mesorrhine or platyrrhine
shaped nose, who may have a characteristically broad nasal bridge
and wide alar base, but who cannot deliberately flare their nostrils
will not experience any appreciable diminution in the involuntary,
dynamic nasal flaring or even narrowing of their nasal aperature
with injections of OnaBTX-A, and therefore should not be treated.
Conversely, patients with a leptorrhine shaped nose who are afflicted
with an involuntary dynamic nostril flare will reap some benefit from
injections of OnaBTX-A. For these patients, carefully placed injec­
tions of OnaBTX-A into the primary nasal dilators (anterior and pos­
terior dilator nares) and secondary nasal dilators (levator alae nasi,
i.e., the medial alar portion of the LLSAN and the depressor septi
nasi) will diminish a dynamic nasal flare, but will not appreciably
alter the vertical orientation of the nostril aperture (Figure 14.28).
However, an overzealous treatment with OnaBTX-A in a leptorrhine
nose may more easily result in an adynamic nose than an overdose in
(a)
(b)
Figure 14.27  A 57-year-old patient at rest (a) before and (b) 4 weeks after a treatment with OnaBTX-A. A slight reduction of a nasal flare was achieved with 5 U of
OnaBTX-A injected into the posterior dilator naris (alar nasalis) bilaterally. Note the more vertical orientation of the nasal base after treatment.

14.  cosmetic uses of botulinum toxin a in the mid face
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a mesorrhine or platyrrhine shaped nose (see nasal tip ptosis below).
For some patients in whom the secondary nasal dilator, the depres­
sor septi nasi may be strong and very active, their nasal flaring may
be accompanied by a dynamic downward and upward movement of
the nasal tip while they pronounce certain words, especially those
containing W, O, U, and Q. In these patients, an injection of 2–4 U of
OnaBTX-A into the center of the columella along with the injections
of the primary nasal dilators is appropriate and at times necessary to
sufficiently relieve their troublesome nasal flaring.
Outcomes (Results) (See Appendix 5) When Treating a Nasal Flare
For those individuals who are plagued with an involuntary propen­
sity for dilating their nostrils when they breathe, speak, smile, or ani­
mate, or if they can flare or dilate their alae nasi willfully, injections
of OnaBTX-A will decrease the frontal diameter of their nostrils and
give their nose a narrower, more vertically leptorrhine appearance,
without interfering with inspiration (Figure 14.28). Results can last
up to 3–4 months and sometimes longer with repeat treatments. For
patients who do not have well-developed muscle fibers of the anterior
and posterior dilator nares and levator alae nasi (medial alar portion of
the levator labii superioris alaeque nasi) and depressor septi nasi, and
cannot dilate their nostrils at will, no amount of OnaBTX-A will relax
these muscles enough to reduce their dynamic alar flaring or narrow
their nostril aperature (see nasal tip ptosis below).
Complications (Adverse Sequelae) (See Appendix 6) When
Treating a Nasal Flare
If patients are not selected properly, injections of OnaBTX-A might
not be effective; then time, effort, and money will have been wasted.
Otherwise, these patients experience no other adverse sequelae, except
the usual ones that occur with transcutaneous injections, including
pain, edema, erythema, and possible ecchymoses. Transcutaneous
injections of the taut skin of the ala nasi with any injectable can be par­
ticularly painful. There have been no reports of difficulty with inspi­
ration, nasoalar collapse, or nasal valve obstruction in those patients
who have been treated successfully or unsuccessfully with OnaBTX-A
to narrow an excessively wide nasal base or diminish dynamic alar flar­
ing. However, the physician injector must not dismiss the potential or
ignore the possibility for an adynamic nose and nostril collapse with
forced inspiration inadvertently caused by either overzealous dosing or
by misplaced injections of OnaBTX-A or both, especially when inject­
ing someone who can only weakly dilate and flare their nostrils. Only
precise amounts of low dose, low volume OnaBTX-A should be accu­
rately injected in the mid and lower face (see nasal tip ptosis below).
Treatment Implications When Injecting the Nose for Nasal Flare

1. Treat only those individuals who can actively and willfully flare
their nostrils.

2. Dynamic nasal flaring is predicated upon the particular shape
of the nose and the different configuration and strength of the
muscles present in the nose.

3. Not every nose has the same morphology of muscles configured
in the same way with the same amount of strength.

4. Broader based noses with wide alae nasi and horizontally ori­
ented nostrils have stronger anterior and posterior dilator nares
and secondary nasal dilators with a predisposition for voluntary
and involuntary dynamic nasal flaring.

5. Injections of a total of 4–10 U of OnaBTX-A along the alar rim
and in the center of each ala nasi will relax the anterior and pos­
terior dilator nares and diminish the involuntary flaring of the
nostrils.

6. Treating hyperkinetic dilator nares with OnaBTX-A can pro­
duce an overall narrower nasal aperture without interfering
with normal or forced respiration.

7. No adverse side effects have been identified with injections of
OnaBTX-A in the nose.
NASAL TIP PTOSIS
Introduction: Problem Assessment and Patient Selection
With age, the nasal tip in some individuals naturally rotates down­
ward, decreasing the angle between the upper lip and the columella.
This occurs partly because of the pull of gravity and partly because of
the pull of a hyperkinetic muscle of the nasal septum (i.e., depressor
septi nasi). When this occurs, a person may possess the appearance of
senility, feebleness, and decrepitude, projecting a pathetic and even
sinister demeanor. There are others who, because of idiosyncratic skel­
etal morphology, possess a downwardly rotated nasal tip since birth
(Figure 14.29). Still there are others whose nasal tip will noticeably
and dynamically rotate downward in an up and down motion as they
speak or pucker their lips, regardless of age (Figure 14.30). For those
whose nasal tip actively moves and rotates downward when depress­
ing the upper lip or when speaking, OnaBTX-A injections have pro­
vided a noninvasive means to elevate and project the nasal tip upward.
Injections of OnaBTX-A will also stop the repeated up and down
dynamic movement of the nasal dome while speaking, smiling, or
drinking.
However, for an adynamic, static, inferiorly pointing nasal tip,
only soft tissue fillers or surgical rhinoplasty can be corrective
(Figure 14.31). An adynamic, ptotic, or an otherwise dynamic,
(a)
(b)
Figure 14.28  A 47-year-old patient with a leptorrhine shaped nose at rest (a) before and (b) 2 weeks after 6 U of OnaBTX-A was injected into each ala. A slight reduction of
an involuntary dynamic nasal flare was achieved.

Botulinum Toxins in Clinical Aesthetic Practice
204
plunging nasal tip and its nasolabial angle must be evaluated on lat­
eral view28,33 (Figures 14.29 through 14.31). The nasolabial angle is
the relationship of the nasal base to the upper lip (Figure 14.31). The
literature is replete with various methods of measuring this angle
and its defining anatomical components. Customarily, the nasola­
bial angle is reported to range from 90 to 120 degrees allowing the
treating physician to determine what the “ideal” nasolabial angle
might be for the individual patient seeking treatment.33 Armijo
et al. recently studied 10 post-rhinoplasy men and 10 post-rhino­
plasty women and concluded that the norms for the “ideal” naso­
labial angle are changing and the ideal ranges for both men and
women are not only more acute but similar in comparative angles
to one another than previously reported. In their study, they found
that the ideal nasolabial angle for men ranged from 93.4 to 98.5
degrees, and for women it ranged from 95.5 to 100.1 degrees.33
Dynamic nasal tip ptosis can be accompanied by excessive upper
lip shortening and occasionally, the presence of a gummy smile and
a transverse crease across the upper lip and philtrum, referred to as
the “rhinogingivolabial syndrome” in the surgical literature (Figure
14.30).34–37 This horizontal upper lip crease can be exaggerated in
(a)
(b)
(c)
(d)
(e)
Figure 14.30  (a, b) This 26-year-old has a dynamic nasal tip ptosis, an upper lip shortening, an asymmetric posterior gummy smile, and a transverse line across her upper
lip when smiling before OnaBTX-A. (c, d) View of the profile of the same patient. Note the dynamic nasal tip ptosis, gummy smile, narrowing of the nasolabial angle and
downward turn of the nose when actively smiling. (e) Same patient seen 1 week after OnaBTX-A treatment. Note the reduction in the gummy smile and nasal tip ptosis
with smiling. (See Figure 14.32.)
Figure 14.29  A naturally, downwardly rotated nasal tip in this 37-year-old patient.

14.  cosmetic uses of botulinum toxin a in the mid face
205
older patients with dermatochalasis and skin laxity Figures 14.23
and 14.24). It also is found in younger patients when there is retrac­
tion and curling of a short upper lip with smiling (Figures 14.30
and 14.32).35,38 These patients typically will also exhibit an exces­
sive amount of maxillary alveolar gingiva when smiling or laugh­
ing, known as a “gummy smile” (Figure 14.30b,d) (see below).
Nasal tip ptosis is not a rare problem and it can be seen in different
ethnic noses worldwide.36 Depending on a person’s idiosyncratic
anatomy and strength of the relevant muscles involved, not all the
upper lip components (gummy smile and midphiltral transverse
crease) associated with nasal tip ptosis are present in all patients
concomitantly.37
Functional Anatomy (See Appendix 2) of Nasal Tip Ptosis
The depressor septi nasi is a short, relatively thick, paired muscle
located on either side of the nasal septum that may be absent up to
20% of the time10 (Figure 14.33). It is considered a component part
of the anterior dilator naris by some. The depressor septi nasi origi­
nates at the center of the incisive fossa of the maxilla deep within the
orbicularis oris (Figure 14.33).9,10,35 Its fibers interdigitate with the
superficial muscle fibers of the orbicularis oris and course upward
within the mucous membrane of the upper lip to insert into (a) the
superior aspect of the maxilla close to the medial crura of the lower
lateral cartilage, (b) into the anterior nasal spine, (c) into the mobile
cartilaginous nasal septum, and (d) the mucous membrane undersur­
face of the ala nasi. A few muscle fibers may even continue upward
between the medial crura and into the nasal tip (Figure 14.33).9,10
Rohrich et al. identified three types of depressor septi nasi from their
cadaver dissections. Type I depressor septi nasi, the most prevalant
(62%), was visible, identifiable, and interdigitated completely with the
orbicularis oris at its origin and then terminated in the medial crural
footplates. Type II depressor septi nasi, the second most commonly
seen (22%), was also visible and identifiable but revealed little or no
interdigitation with the orbicularis oris (Figure 14.33c, left). Type III
depressor septi nasi, seen least often (16%), was only rudimentary or
even absent38 (Figure 14.33c, right). Even when present, however, the
strength and direction of pull of the depressor septi nasi varied from
patient to patient.39
When a person smiles the depressor septi nasi contracts.
Depending on its size, strength, and the extent of its muscle fibers
interdigitating with muscle fibers of the orbicularis oris, the depres­
sor septi nasi can lower the tip of the nose, shorten the upper lip,
pull the nasal septum downward, draw the ala nasi inferiorly, and
narrow the nostril transversely.9,10 In some individuals, fibers of the
dilator nares (both anterior and posterior) have also been found to
interdigitate with those of the depressor septi nasi. Consequently,
(a)
(b)
Figure 14.31  This 48-year-old patient has an adynamic, static, inferiorly rotated nasal tip, which could only be treated with a soft tissue filler. She is seen here (a) before and
(b) 2 weeks after treatment with an intracolumella injection of calcium hydroxylapatite. Note the retracted base of columella; the acute columella-labial angle (<90°) and
the inferiorly rotated and dropped nasal tip before treatment; and the anterior projection of base of columella; the obtuse columella-labial angle (∼110°) and the superiorly
rotated and enhanced nasal tip projection after the intracolumella injections of calcium hydroxylapatite.
(a)
(b)
Figure 14.32  A 52-year-old patient curls the upper lip with smiling. Note the visible upper lip transverse crease and downward rotation of the nasal tip. Also note the dif­
ference between this older patient and the younger one of Figure 14.30.

Botulinum Toxins in Clinical Aesthetic Practice
206
when the depressor septi nasi contracts in unison with the dilator
nares as the upper lip is set in motion (e.g., when smiling or pursing
the lips to whistle, kiss, or pronounce words containing W, O, U, J,
M, G, B, P, Q sounds), a concomitant widening of the nasal aperture
will then occur and the nasal tip will actively rotate downward and
upward and often repeatedly while one is speaking (see Figures 14.30
and 14.32) (see nasal flare above).
Yet in some other individuals, the lip and alar insertions of the
depressor septi nasi are also comingled with lateral labial fibers of
the LLSAN.35 Consequently, during animation when the nasal tip is
pulled downward while the upper lip is pulled upward in a curling
motion, a horizontal upper lip crease appears and a maxillary gummy
show is the result (Figures 14. 23, 14.24 and 14.30) (see below, gummy
smile,). There is also another subset of individuals that produces an
ominous and unfriendly sneer when they smile, as their nasal tip
rotates downward from the pull of their particular depressor septi
nasi and the nostrils and alar base are simultaneously pulled upward
by their LLSAN35,40 (Figure 14.30d). Because of individual variability
in the anatomy of the depressor septi nasi, orbicularis oris, anterior
and posterior dilator nares, accessory nasal tip musculature (apicis
nasi and compressor narium minor) and the medial alar portion of
the LLSAN (or levator alae nasi), along with the multifactorial etiol­
ogy of a dynamic nasal tip ptosis with or without upper lip and nasal
base retraction, injections of OnaBTX-A to elevate and project the tip
of the nose usually is not as easy to perform as one might think.
Dilution (See Appendix 3) When Treating Nasal Tip Ptosis
In the paranasal area, minimum amounts of OnaBTX-A should
be used so as not to accidentally affect the levators of the upper lip
by the inadvertent spread of OnaBTX-A. Therefore, a 100 U vial of
OnaBTX-A should be reconstituted with only 1 mL of normal saline.
Dosing: How to Correct the Problem (See Appendix 4) (What to
Do and What Not to Do) When Treating Nasal Tip Ptosis
For those patients who can intentionally depress and rotate the tip
of their noses downward by puckering or lowering their upper lip,
noninvasive injections of OnaBTX-A now can be helpful in rais­
ing and projecting their nasal tip instead of resorting to the more
invasive types of different surgical resections.36–39,41 To effectively
treat a dropped nasal tip, first identify the concave curvature that
demarcates the junction between the columella with the center of
the upper lip. Then ask the patient to smile and a more pronounced
groove or crease becomes more apparent at the point in question
(Figure 14.34). Next, with the patient in a sitting or semireclined
position have the patient depress their upper lip downward, widen­
ing that junction between the base of the columella and the upper
lip. This maneuver elongates the depressor septi nasi, separating
it functionally and anatomically away from the orbicularis oris in
those 30%–40% of individuals whose depressor septi nasi does not
interdigitate with muscle fibers of the orbicularis oris and whose
nasal tip ptosis does not simultaneously retract and shorten the
(b)
(c)
(a)
1
2
3
4
1
2
3
4
Figure 14.33  (a) Depressor septi nasi may intermingle with the anterior dilator naris and superficial fibers of the orbicularis oris. 1, posterior dilator naris (alar nasalis);
2, anterior dilator naris; 3, depressor septi nasi; 4, orbicularis oris. (b) There are three types of depressor septi muscles: the most common (in an estimated 62% of popula­
tion) is type I (shown here), visible, identifiable, and traceable to full interdigitation with the orbicularis oris from the medial crural foot plate. Type I is thought to be
responsible for producing a horizontal crease above the upper lip when an individual animates, especially when smiling. (See further Reference 37) 1, depressor septi
Type I; 2, orbicularis oris. (c) Type II muscles (left side here; 22 percent) are visible and identifiable but, unlike Type I group, demonstrate little or no interdigitation with
the orbicularis oris; and Type III (right side here; 16%) includes cases where no, or only a rudimentary, depressor septi muscle is visible. 3, depressor septi Type II; 4,
depressor septi Type III.

14.  cosmetic uses of botulinum toxin a in the mid face
207
upper lip when they smile. This allows one to place the needle pre­
cisely into the depressor septi nasi at the base of the columella, and
not into fibers of the orbicularis oris, before injecting OnaBTX-A.
Then grasp the columella between the thumb and index finger of
the nondominant hand at the same time the patient is forcing the
upper lip downward and underneath their incisors and canines
(Figure 14.35). Another technique is to lift the tip of the nose supe­
riorly and gently push it posteriorly with the thumb of the non­
dominant hand (Figure 14.35).
Depending on the strength of the depressor septi nasi, 2–4 U of
OnaBTX-A can be injected just superior (1–2 mm) to the labiocol­
umella boundary line crease (Figure 14.35). If the strength of the
depressor septi nasi is visibly excessive causing it to be hyperfunc­
tional, an additional 2–4 U of OnaBTX-A can be injected into the
middle of the columella and even into the nasal tip to neutralize any
additional downward pull of the compressor narium minor or the
dermocartilaginous ligament of Pitanguy36 (Figure 14.35c and d).
Stronger muscles will require higher doses of OnaBTX-A.42 In some
patients whose depressor septi nasi also interdigitates with the ante­
rior dilator naris, an additional injection of 2–6 U of OnaBTX-A on
both lateral aspects of the nasal tip, that is, into the center of the ala
nasi just behind the alar rim, will be necessary to effectively elevate
and project the nasal tip.42
To reduce the depth of the horizontal upper lip crease, injections of
OnaBTX-A should be placed lateral to the alae nasi and into the lateral
labial fibers of the LLSAN. This actually is the treatment for an exagger­
ated maxillary gummy smile and is discussed in detail below.
Outcomes (Results) (See Appendix 5) When Treating Nasal Tip
Ptosis
Injecting OnaBTX-A into the depressor septi nasi will relax the mus­
cle, lifting and projecting the nasal tip upward (Figure 14.36). The
combination of injecting both the columella and the alae nasi just lat­
eral to the nasal tip with OnaBTX-A will relax the lower end of the
nostrils and base of the nose, producing additional lifting of the nasal
tip and lateral widening of the nostrils by the medial (alar) fibers of the
LLSAN provided this muscle remains functional (Figure 14.37).42 If
one can see obvious movement and a downward rotation of the nasal
tip when a patient smiles, speaks, depresses the upper lip, puckers or
purses the lips, then injections of OnaBTX-A will be effective (Figures
14.38 and 14.39). Results can last 3–4 months and slightly longer
with repeat treatments. If there is no movement of the nasal tip when
the upper lip is depressed or while the patient smiles, speaks, puck­
ers, depresses the upper lip, or purses the lips, OnaBTX-A injections
should not be given.
Perez-Atamoros has devised a therapeutic dosing scheme
whereby he can predict the height change in the nasal tip elevation
and projection in patients he treats with OnaBTX-A.42 Injecting 2 U
of OnaBTX-A deeply into each of the right and left sides of the nasal
tip into the anterior dilator naris and 2 U of OnaBTX-A into the
depressor septi nasi (total of 6 U of OnaBTX-A) produces a slight
elevation of the nasal tip. Approximately 4 U of OnaBTX-A injected
into each of the right and left side of the nasal tip and the depressor
septi nasi (total of 12 U of OnaBTX-A) produce a medium elevation
of the nasal tip. For a high elevation and projection of the nasal tip,
6 U of OnaBTX-A into each of the right and left anterior dilator
nares and depressor septi nasi (total of 18 U of OnaBTX-A) may be
needed (Figures 14.37 and 14.40).42 Results can last as long as 4–5
months. This is due presumably to the compensatory upward con­
traction of the secondary nasal dilator, the levator alae nasi, that is,
the medial (alar) fibers of the LLSAN.
When a horizontal upper lip midphiltral crease is accentu­
ated with smiling, with or without a downward rotation of the
nasal tip, an additional 1–3 U of OnaBTX-A can be placed into
each lateral portion of the LLSAN as described below in the sec­
tion on a gummy smile. Injecting the depressor septi nasi and the
lateral (labial) fibers of the LLSAN with a very small amount of
OnaBTX-A not only can diminish the transverse line of the upper
lip, but, when done appropriately, it also can provide an apparent
increase in the vertical distance between the columella and vermil­
lion border. This occasionally can create a fuller, more voluminous
upper lip for some patients. However, for many others, especially
for older patients, similar injections can adversely further elon­
gate a thin and low-hanging upper lip and vermillion.43 Dayan and
Kempiners35 also found that with 5 U of OnaBTX-A placed into
each depressor septi nasi and 3 U placed into each LLSAN, on lat­
eral view the nasal tip became less ptotic, the alar facial insertion
remained in a more neutral position, and the nasolabial angle wid­
ened from 110 to 115 degrees. In addition, on frontal view there was
a relative elongation and a relaxation in the curling of the upper
lip with smiling and laughing that accompanied a diminution of
the mid philtral horizontal crease, a more horizontal orientation to
the alar base insertion, and an attenuation in the appearance of a
snarl (Figure 14.30). Consequently, the depressor septi nasi is one
of the muscles that also might need to be weakened when treat­
ing a patient for an exaggerated upper gummy smile (see “Gummy
Smile” below). When there still is evidence of a horizontal upper lip
crease after an appropriate treatment of OnaBTX-A, injections of a
strategically placed soft tissue filler may be the only solution for its
complete elimination (see Gummy Smile below) (Figure 14.41). The
(a)
(b)
Figure 14.34  The concave curvature that demarcates the junction between the columella with the center of the upper lip (a) becomes a more pronounced groove or crease
when a person smiles (b).

Botulinum Toxins in Clinical Aesthetic Practice
208
(a)
(c)
(d)
(b)
Figure 14.35  (a, b) Injection of the depressor septi nasi in the center of the columella. Note how the patient depressing their upper lip downward and the injector pinching
the columella facilitate the injection. (c, d) Injection of the depressor septi nasi at the base of the columella. Note the placement of the needle, above the orbicularis oris,
while the thumb of the nondominant hand gently pushes the nasal tip upward and backward.
(a)
(b)
Figure 14.36  This 41-year-old at rest (a) before and (b) after 4 U of OnaBTX-A were injected at the base and midsection of the nasal columella. Note the slight elevation of
the ptotic nasal tip after treatment. Dynamic tip rotation with speaking and lip puckering was also reduced.

14.  cosmetic uses of botulinum toxin a in the mid face
209
Before
(a)
(b)
(c)
2 weeks after
1 month after
Figure 14.37  Exaggerated elevation of the nasal tip, flattening of the tip projection and excessive widening of the nostrils can be seen in this patient who was injected with a
total of 18 U of OnaBTX-A (6 U into each anterior and posterior dilator nares equally divided per side and 6 U into the depressor septi nasi in the base and mid columella).
(Courtesy of Dr. Francisco Perez-Atamoros.)
(a)
(b)
Figure 14.38  (a) The nasal tip of this 26-year-old patient actively rotated downward with speaking, smiling, and laughing before 4 U of OnaBTX-A: 2 U at the base and 2 U
in the center of the columella. (b) Same patient 1 week after OnaBTX-A treatment.

Botulinum Toxins in Clinical Aesthetic Practice
210
effect of the injected OnaBTX-A in this area sometimes lasts for
only 2–3 months, and even less in some patients.
Complications (Adverse Sequelae) (See Appendix 6) When
Treating Nasal Tip Ptosis
When treating nasal tip ptosis, it is extremely important for the phy­
sician injector to assess accurately a patient’s nasal morphology, the
structure and composition of the muscles that are actively functioning
in that particular person’s nose. Not every muscle in every patient’s
nose functions exactly the same way, with the same strength or in
exactly the same direction. The existing functional anatomy of an
individual patient depends on the size, shape, sex, age, and racial and
ethnic background of that patient. Overzealous injections with high
doses of OnaBTX-A only into the interdigitating fibers of the depres­
sor septi nasi and anterior dilator nares without relaxing the posterior
dilator nares or the medial alar fibers of the LLSAN can result in an
unattractive, exaggerated widening of the nostrils along with the
projection and elevation of the nasal tip (Figure 14.37). This forced
widening of the nostrils in some patients is accompanied by persistent
pain and soreness over the nasal tip that can last for over 2 weeks.42
Therefore, it is extremely important to treat each person individually
with the appropriate technique of dosing and injection placement.
Weakening only the depressor septi nasi may just elevate the
nasal tip. However, if the OnaBTX-A diffuses laterally from the
midpoint of the base of the nasal columella and into the central
upper lip levators (i.e., LLSAN, levator labii superioris, or zygomati­
cus minor), then the upper lip can become elongated and thinned,
obliterating the depth of the philtrum and the contour of the phil­
tral columns. Asymmetry of the lips and alterations in functional
buccal sphincteric control may also result, producing difficulty
(a)
(b)
Figure 14.39  (a) The nasal tip of this 52-year-old patient actively rotated downward with speaking, smiling, and laughing before 4 U of OnaBTX-A: 2 U at the base and 2 U
in the center of the columella. (b) Same patient 2 weeks after OnaBTX-A treatment. Note the slight nasal tip elevation and projection.
(a)
(b)
4 + 4
8
Figure 14.40  Nasal tip (a) before and (b) 1 month after a treatment with OnaBTX-A. An overall total of 16 U of OnaBTX-A were injected: 8 U into the anterior dilator
nares (4 U on each side) and 8 U (4 U at the base and 4 U into the mid portion of the columella) into the depressor septi nasi to achieve these results. (From Atamoros, PF.
Botulinum toxin in the lower one–third of the face. Editor AV Benedetto. Clin Derm 2003; 21: 505–12, by courtesy of Dr. Francisco Perez-Atamoros.)

14.  cosmetic uses of botulinum toxin a in the mid face
211
with eating, swallowing, and speaking. Unless there is an obvious
downward displacement of the anterior aspect of the nose and nasal
tip when a patient forcibly puckers or lowers his or her upper lip,
speaks, or smiles, injections of the depressor septi nasi should not
be attempted.
Treatment Implications When Injecting the Nose for Nasal Tip Ptosis

1. The tip of the nose may rotate downward because of muscle con­
traction, age, and gravity.

2. When the depressor septi nasi visibly depresses the tip of the
nose when one smiles, speaks, puckers, or purses the lips,
OnaBTX-A injections will elevate and project the nasal tip.

3. In some patients, additional deep injections of OnaBTX-A into
the anterior dilator naris along the alar rim toward the nasal tip
as well as the depressor septi nasi may be necessary to elevate
and project the tip of the nose.

4. Inject OnaBTX-A on a case by case basis into all the nasal mus­
cles which contribute to a particular person’s nasal tip ptosis.
Injecting OnaBTX-A into the columella (depressor septi nasi)
and along the alar rim (anterior dilator naris) can cause an
amplified widening of the nostrils if the posterior dilator naris
and medial alar portion of the levator labii superoris alaque nasi
are not weakened.

5. Misplaced and overzealous treatment with OnaBTX-A can
cause excessive nostril widening, prolonged pain, an exagger­
ated elevation, and a flattening of the nasal tip projection.

6. Diffusion of OnaBTX-A lateral to the base of the columella can
affect the upper lip levators, elongating the upper lip, blunting
the contour of the philtrum, and causing lip asymmetry.

7. Upper lip asymmetry and oral sphincter weakness can result
from injecting too high a dose of OnaBTX-A too superficially
at the base of the columella which can diffuse into the central
upper lip levators and superficial fibers of the orbicularis oris.
NASOLABIAL FOLDS
Introduction: Problem Assessment and Patient Selection
Chronological aging and a downward shift of soft tissue in the mid
cheek area can deepen a nasolabial sulcus, which, in turn, augments
its fold. Accentuated by side lighting and shadows, the nasolabial
fold is enhanced by the overall diminution of structural skeletal
and muscular support and intensified by the incessant effects of
aging and the pull of gravity. The descent of cheek soft tissue mass
occurs in the infraorbital and submalar area at different depths and
stages in an inferiomedial direction and varies with each individ­
ual.41,44–46 The redistribution of facial soft tissue and fat increases
with time and leads to the development of a characteristic vertical
(a)
(b)
(c)
(d)
Figure 14.41  Note the horizontal crease that is visible above the upper lip (a) at rest and (b) accentuated while smiling in this 69-year-old patient 3 weeks after a treatment
with OnaBTX-A. (c) Proper injection technique for eliminating the transverse crease of the upper lip. (d) The same patient seen in (a, b) immediately following treatment
with a cohesive polydensified matrix type of hyaluronic acid-based injectable filler. Note the complete effacement of the transverse upper lip crease.

Botulinum Toxins in Clinical Aesthetic Practice
212
groove and fold that extend from the alar facial sulcus to the lateral
labial commissures.43 The appearance of these so-called nasolabial
folds probably is more frequently seen in genetically predisposed
individuals, but more than likely they also can be acquired by those
whose mid facial movements are constant, excessive, and intense.47
Usually absent in children, nasolabial folds emerge around the age
of 25 years in those individuals who continuously display constant
expressions of emotion, laughter, fatigue, pain, and so on. By age
35, the nasolabial folds become more fixed in those so predisposed
and exhibit a great deal of morphologic variability.47,48 Deep, diago­
nal folds that form at the sides of the nose and continue downward
toward the angle of the mouth, and at times even lower into mari­
onette lines, project an attitude of disgust and dismay and are a
characteristic sign of advanced age. These deep furrows and folds
remain as one of the more difficult and still barely correctable har­
bingers of senescence in the treatment of the aging face. In the past,
different surgical procedures have attempted to efface the outline
and depth of the nasolabial groove, thereby flattening the fold. These
procedures are fraught with scars and failure.40 Recently, injections
of different soft tissue fillers have been most beneficial in achieving a
modicum of success in effacing a deep nasolabial fold and restoring
lost soft tissue support in the center of the face. The minimally inva­
sive injection of fillers probably is still the best method for elevating
and diminishing the inescapable, recalcitrant evidence of impend­
ing senescence, the deep nasolabial sulci, and folds. Nevertheless,
injections of OnaBTX-A also have been employed in an attempt
to reduce the depth and obtrusive appearance of nasolabial folds.
Unfortunately, intramuscular injections of OnaBTX-A appear not
to be the long sought-after panacea for this problem and they too
have proven to be fraught with complications and failure in this
area of the mid face.
Functional Anatomy (See Appendix 2) of Nasoloabial Folds
There is significant variation in the anatomy that creates the naso­
labial fold, which extends from a point lateral to the nasal ala to a
point lateral to or lower than the oral commissure. The etiology of
a prominent nasolabial fold is the result of multiple contributing
alterations occurring with advancing age, including varying degrees
of soft tissue atrophy involving the skin, fat, and muscles along with
ptosis and downward migration of fat and its retaining ligaments,
in conjunction with atrophy of facial bones resulting in widening of
the orbits, nasal pyriform aperture, and retrusion of the maxilla and
mandible.8,41,45,49 The cutaneous insertions of the different mimetic
facial muscles along this fold may promote the early appearance and
deepening of the nasolabial fold and furrow or sulcus, starting in
those so predisposed persons in their mid to late twenties.47 In older
patients, a combination of any of the following also may contribute to
a prominent nasolabial fold:
• Loss of skin thickness over the sulcus
• Redundant skin lateral to the sulcus
• Excessive fat deposits lateral to the sulcus that are fixed in place
by retaining ligaments, with or without Ptosis of the malar and
submalar fat laterally because of a weakening of the SMAS in
the mid upper cheek
Aging and frequent mimetic action by the causative facial muscles
can deepen the vertical sulcus that runs from the upper border of the
nasofacial angle downward and laterally toward the commissures of the
mouth. Depending on the unique morphologic variations of an indi­
vidual’s facial anatomy, it is the resultant idiosyncratic movements of
a combination of any one of the mid face mimetic muscles (zygomatic
complex, the central upper lip levators, and the levator anguli oris and
risorius) that are responsible for elevating the upper lip and producing
a person’s characteristic smile.47,48,50 They also contribute significantly
either individually or as a group to the initial formation and the pro­
gressive intensification of the nasolabial folds (Figure 14.42).
Nasolabial folds can appear convex (60%), straight (30%), or concave
(10%)48 (Figures 14.43 and 14.44). The length of a nasolabial fold also
can vary from being one that is extended (42%), short (38%), or con­
tinuous (20%) from the alar base to the mandible47,48 (Figure 14.45).
With respect to an individual’s idiosyncratic facial morphology, the
nasolabial fold can be divided into three sections: the upper or medial,
middle, and lateral or lower sections (Figure 14.46).50 However, no
significant correlation was found by Pessa et al. between the muscles
present and their patterns of perioral attachments, and the length and
contour of the nasolabial crease and fold.48
In many patients, according to some authors, it is the LLSAN that
is the muscle most responsible for producing the upper medial por­
tion of the nasolabial fold and the LLS for deepening the middle of the
nasolabial fold.3,4,47,50–52 It is the zygomatic major, levator anguli oris,
risorius and, at times, the LLS which contribute primarily to deepen­
ing and extending the lower lateral aspect of the nasolabial fold when
they laterally retract and elevate the upper lip to produce a smile.4 In
some individuals, however, the LLSAN is less important in the forma­
tion of a smile, especially if elevating the medial aspect of the upper
lip is minimal when they do smile (see Gummy Smile below) In many
other individuals, the zygomaticus complex, along with a contribution
from the LLS and levator anguli oris, can deepen the middle as well as
the lower lateral portions of the nasolabial fold.
In addition, aging and redundant inelastic skin cause certain indi­
viduals to exaggerate lateral canthal wrinkles, extending crow’s feet
downward over the surface of the mid and lateral cheeks when they
smile enthusiastically (Figure 14.47). This seems to occur in certain
individuals because their decussated zygomaticus complex muscle
fibers (zygomaticus major and zygomaticus minor) also interdigitate
with the lower medial and lateral aspects of the orbital orbicularis
oculi.53 In most individuals, the zygomaticus major and levator anguli
oris help to elevate the corner of the mouth and move it laterally and
1
2
3
4
5
Figure 14.42  Muscles that contribute to the formation of the nasolabial fold.1, leva­
tor labii superioris alaeque nasi; 2, levator labii superioris; 3, zygomaticus minor; 4,
zygomaticus major; 5, risorius.

14.  cosmetic uses of botulinum toxin a in the mid face
213
slightly upward with smiling. In so doing, they also can mobilize mid
cheek skin upward and laterally, extending the lower crow’s feet down
the face, especially in individuals who have inelastic, loose, redun­
dant skin (Figure 14.47).
The zygomaticus major originates on the lower aspect of the zygo­
matic bone, just anterior to the zygomaticotemporal suture line (Figure
14.42). It then continues downward obliquely toward the angle of the
mouth and joins other muscle fibers just lateral to the commissure,
interdigitating with them as they all interlace with each other to form a
muscular node, called the modiolus. Then the zygomaticus major exits
the modiolus and inserts its fibers into the corner of the mouth. In the
modiolus the zygomaticus major co-mingles with fibers of the levator
anguli oris, depressor anguli oris, risorius, buccinator, platysma, and
superficial and deep fibers of the orbicularis oris.54 In a study by Pessa
et al., the zygomaticus major was present as a single muscle in 66% of
the 50 cadavers examined.48 In the other 34% of the cadavers studied,
the zygomaticus major appeared bifid with two separate muscle bun­
dles, which was more commonly found in the female cadavers (65%).
The larger main bundle decussated into the modiolus and then inserted
into or above the corner of the mouth, while the more superficial and
narrower bundle inserted into the deep dermis below the corner of the
mouth.47,48 When pulled on separately, the superficial bundle created a
(a)
(b)
(c)
Figure 14.44  Clinical examples of the types of nasolabial folds: (a) convex; (b) straight; (c) concave. (See further References Zufferey J. Plast Reconstr Surg 1992; 89(2):
225–31 and Pessa JE et al. Plast Reconstr Surg 1998; 102(6): 1888–93.)
(a)
(b)
(c)
Figure 14.43  The three different morphological types of nasolabial folds: (a) convex; (b) straight; (c) concave. (See further Reference Zufferey J. Plast Reconstr Surg 1992;
89(2): 225–31.)
(a)
(b)
(c)
Figure 14.45  Different lengths of the nasolabial folds in relationship to the corner of the oral commissures: (a) short; (b) extended; (c) continuous. (See further Reference Pessa
JE et al. Plast Reconstr Surg 1998; 102(6): 1888–93.)

Botulinum Toxins in Clinical Aesthetic Practice
214
concave nasolabial fold, and the main bundle created a convex nasola­
bial fold. On occasion, additional dermal insertions were found along
the course of the smaller, more superficial bundle. This was thought to
represent the reason for the presence of parabuccal dimples.
The zygomaticus minor, on the other hand, when present, originates
more medially on the zygoma than the zygomaticus major, just behind
the zygomaticomaxillary suture line, and more anteriorly and inferi­
orly to the origin of the zygomaticus major. At its origin, the zygomati­
cus minor is lateral to the LLSAN, superficial to the LLS, and deep to
and interdigitates with the orbital orbicularis oculi53,55 (Figure 14.42).
Pessa et al. found the zygomaticus minor present only in 36% of
their Caucasian cadavers studied, while Youn et al. found the zygo­
maticus minor present in 95% of their Korean cadavers48,53 One of the
reasons why the zygomaticus minor was found so much more fre­
quently in Korean cadavers was because Youn and colleagues were
able to identify the elusive zygomaticus minor at its origin, that is, by
the presence of muscle fibers on the zygoma and not by trying to iden­
tify separate muscle fibers of the zygomaticus minor from those of the
zygomaticus major. When they initially attempted to locate the zygo­
maticus minor without identifying it at its bony origin, their identifi­
cation of the zygomaticus minor was just as low in frequency and had
similar morphology as those of other studies, that is, 34.4% (21 of 61
of the cadavers studied). However, after determining the origin of the
zygomaticus minor on the zygomatic bone, its nonexistence in the
Youn et al. study dropped to only 4.9% (3 of 61). They then concluded
that the presence or abscence of the zygomaticus minor should be
based on its bony origin and the direction of the projection of its mus­
cle fibers and not on its differentiation from the zygomaticus major.
Interestingly, they also found muscle fibers of the zygomaticus minor
could not be distinguished from those of the zygomaticus major in
34.4% (21 of 61) of the cadavers examined. When the two muscles
could be identified as separate muscle bundles, the zygomaticus
minor interdigitated with the inner lower aspect of the orbital orbicu­
laris oculi in 34 of 61 (56%) cadavers examined and continued down­
ward parallel with the upper lip levators (LLSAN and LLS) into the
upper lip. More strikingly, they also found 54 of 61 (88.5%) cadavers
in which muscle fibers of the lateral aspect of the orbital orbicularis
oculi interdigitated with the zygomaticus minor before it inserted
into the upper lip53 (Figure 14.48a) (see Chapter 13, “Lateral Canthal
Lines”). The usual course of the zygomaticus minor, when it is pres­
ent, is to travel downward to insert more medially than the zygomati­
cus major and directly into the upper lip, interdigitating with fibers of
the LLSAN, orbicularis oris, and zygomaticus major, after the zygo­
maticus major exits the modiolus (Figure 14.48b and c).
Choi et al. after their Korean cadaver dissection study classified the
zygomaticus minor into three different types, according to anatomic
morphology and muscle insertion patterns.55 The most commonly
encountered pattern type of zygomaticus minor found in 34 of the 54
(63%) cadavers studied was where the muscle attached directly into
the upper lip either by a straight course in 17 (31.5%) of the speci­
mens or in a curved course also in 17 (31.5%) of the cadavers dissected
(Figure 14.48c1 and c2).
The second most frequently seen pattern of insertion, 15 of 54 (28%)
cadavers studied, was where the zygomaticus minor attached to either
fibers of the orbicularis oris within the upper lip or at the lateral ala
nasi. As the zygomaticus minor passed from its origin on the zygoma
toward its insertion within the upper lip or ala nasi, many of its trans­
verse and descending muscle fibers could not be separated from those
A
B
C
Figure 14.46  Sections of the nasolabial fold: (A) medial (or upper) nasolabial
fold; (B) middle nasolabial fold; (C) lateral (or lower) nasolabial fold. (See further
Reference Pessa JE, Brown F. Aesth Plast Surg 1992; 16: 167–71.)
(a)
(b)
Figure 14.47  (a, b) Lower crow’s feet, lateral cheek rhytides and deep nasolabial folds creating “accordion-like” wrinkles down the cheeks. Note also the horizontal wrinkle
across the philtrum on the upper lip.

14.  cosmetic uses of botulinum toxin a in the mid face
215
of the inner lower aspect of the orbital orbicularis oculi, similar to
what was reported in the Youn study53 (Figure 14.48c3).
The third and least encountered insertion pattern of the zygomati­
cus minor was seen in 5 of 54 (9.3%) cadavers where there were no or
just some very rudimentary muscle fibers of the zygomaticus minor
(Figure 14.48c4).
Youn et al. also found that the origin of the zygomaticus minor
had two different muscular origins on the zygoma. The more super­
ficial origin of the zygomaticus minor that interdigitated with the
orbital orbicularis oculi passed downward and medially into the
upper lip. Whereas the deeper muscle fibers from their origin on the
zygomatic bone attached to the lateral ala nasi possibly creating a
tell-tale small bulge or protrusion on the lateral aspect of the ala nasi
visible in some individuals during facial animation (Figure 14.48d).
These fibers, attached to the lateral ala nasi, also could be seen as
supplementing the actions of the LLSAN, LLS, and anterior and pos­
terior dilator nares in flaring the nostrils and producing a gummy
smile (see Nasal Flare above and Gummy Smile below). This could be
an obvious revealing landmark used to identify those patients who
will benefit from treatments of a nasal flare or a gummy smile.
(a)
(b)
1
1
2
3
4
2
3
4
A
B
C
5
B
C
A
Figure 14.48  (a) The highlighted area (A) is where the zygomaticus minor (ZMi) interdigitates with and is inseparable from the orbital orbicularis oculi (OOc) and is
located (B) approximately 17.8 mm inferior to the Frankfort plane and (C) laterally at 8.9 mm from the vertical line that perpendicularly connects the lateral canthus
and the Frankfort plane. The inseparable interlacing of the two muscles extends medially for a distance of 16 mm. 1, lateral canthus; 2, midpoint of the palpebral fissure;
3, Frankfort plane; 4, zygomaticus minor; 5, zygomaticus major. (b) The zygomaticus minor inserts (A) into the lateral aspect of the ala nasi; (B) into the lower aspect of the
levator labii superioris alaeque nasi; and (C) in the area where the medial margin of the zygomaticus major and the orbicularis oris join. 1, levator labii superioris alaeque
nasi; 2, zygomaticus minor; 3, zygomaticus major; 4, orbital orbicularis oris.
(Continued)

Botulinum Toxins in Clinical Aesthetic Practice
216
The cadaver dissection studies of Youn and Choi versus that of Pessa
underscore the structural consistency, but also the diversity of the mor­
phological composition of the human face and the importance of the
phenotypic influences that race and ethnicity have on the functional
differences of facial mimetic anatomy. In other words, the width, height
and depth of an Asian versus a Caucasian facial skeleton make it more
conducive to having a more robust and significantly more functional
zygomaticus minor in an Asian face than in a Caucasian face. These
and other similar anatomical studies confirm that there are indeed
inter- and intra-racial variations of muscle morphology and movement
which are dependent on the overall skeletal shape and inherent muscle
composition of a particular person’s face, which may vary according
to the different anatomical characteristics of that person’s ethnic and
racial background. There also seems to be a particularly high degree
of variability in mid face musculature according to the anatomic stud­
ies in the literature currently available.48,50,53–55 This high degree of mid
face anatomical variability is embodied in different individuals’ ability
to express the same emotions in a wide range of different but similarly
subtle facial movements with the same or possibly different muscles.
These spontaneous, subconscious, or at times intentional facial mimetic
(c)
(c1)
(c2)
(c3)
(c4)
1
1
1
1
(d)
Figure 14.48 (Continued)  (c) Classification of the zygomaticus minor (1) into 3 types. In type A, the zygomaticus minor was attached only to the upper lip, but the type is
subdivided into 2 subtypes: straight (A-1) (c1) and curved (A-2) (c2). In type B (c3), the zygomaticus minor attached to both the upper lip and the alar portion of the nose
with many of its transverse and descending muscle fibers closely interdigitated with fibers of the inner lower aspect of the orbital orbicularis oculi. In type C (c4), there
was either no or only underdeveloped zygomaticus minor fibers. (See further reference 54) (d) Small protrusion adjacent to ala nasi (arrow) may represent the insertion of
zygomaticus minor muscle fibers. (From Choi DY et al. 2014. Dermatol Surg 40(8):858–63. With permission.)

14.  cosmetic uses of botulinum toxin a in the mid face
217
movements can span a gamut of different emotions from a smile of hap­
piness or pleasure to the laughter of enjoyment or embarassment; from
a grimace of sadness or disappointment to a sneer of scorn or contempt;
from a smirk of arrogance or disdain to a grin of agreement or displea­
sure. All of these facial expressions are centered in the mid face and are
dependent on the slightest mimetic movement of the available facial
muscles, whose presence and actions ostensibly are a reflection of one’s
character, personality and inner feelings, all of which are easily inter­
preted by casual observers. Because of the different vectors of movement
which intrinsically occur consistent with the types of zigomaticus minor
anatomical configurations, one can easily appreciate that different types
of muscular movements can take place to express the same emotion,
expressed by different individuals in their own unique way. Generally,
the zygomaticus minor along with the LLS and the zygomaticus major
pull the upper lip superolaterally, while the LLSAN pulls the upper lip
superomedially, exposing the maxillary teeth and deepening the naso­
labial sulcus and enlarging the fold. Both muscles of the zygomaticus
complex can deepen the nasolabial fold when they contract to produce
a smile. In most individuals, when the zygomaticus minor contracts
together with the central upper lip levators (i.e., LLSAN and LLS), they
will cause the upper lip to curl when expressing smugness, contempt, or
disdain. Likewise, when a person contracts the lateral and medial aspect
of the lower eyelid as in a wink or squint, most of the time the mid to
lateral aspect of the upper lip and cheek also contracts upward.53
Symmetry of the zygomaticus minor was calculated in regard to its
morphology and vectors of movement by Choi et al.55 They found that
the zygomaticus minor was asymmetric in 12 of the 18 (66.6%) cadav­
ers studied, one of the identifiable probable causes of upper lip asym­
metric smiles (see Asymmetric Smiles below).
The LLSAN is a long thin rectangular muscle that originates from
the superior part of the frontal process of the maxilla close to the side
of the nose (Figure 14.49). Covered by the orbital orbicularis oculi, the
facial angular vessels can be found traversing along the nasojugal fold
between the two muscles. As the LLSAN travels obliquely downward
and laterally, it divides into two separate muscle bundles. The one
smaller bundle inserts medially into the perichondrium of the lateral
crus of the greater alar cartilage and skin of the nose, while interdigi­
tating with fibers of the posterior and anterior dilator nares. The other
larger lateral muscle bundle continues downward toward the medial
aspect of the upper lip and crosses over the front of the LLS, merging
its fibers with those of the LLS and orbicularis oris. It inserts under the
dermis and into the overlying skin of the ipsilateral upper lip near the
upper medial part of the nasolabial sulcus and fold. The lateral labial
muscle bundle raises and everts the upper lip and raises, deepens,
and increases the curvature of the upper aspect or medial nasolabial
sulcus. The medial nasal muscle bundle of the LLSAN, also known as
the levator alae nasi, pulls the lateral cartilaginous crus laterally and
upward to dilate the nostrils. It also displaces the circumalar facial
sulcus laterally, modifying its curvature and elevating the nasolabial
sulcus and fold.10
The LLS is the widest of all the upper lip levators. It originates from
the maxilla at the lower margin of the orbit, just above the infraor­
bital foramen, deep to the orbital orbicularis oculi (Figure 14.49).
Coursing downward between the lateral labial bundle of the LLSAN,
the zygomaticus minor, and the levator anguli oris, some of the fibers
of the LLS insert directly into the skin overlying these muscles in the
central and lateral aspect of the upper lip and other fibers interdigi­
tate with those of the orbicularis oris. While still in some individuals
the LLS can interdigitate with the depressor septi nasi. The function
of the LLS is to raise and evert the central aspect of the upper lip.
In conjunction with other muscles, it moves and deepens the middle
of the nasolabial sulcus, especially during expressions of seriousness
and sadness.
The levator anguli oris originates more deeply in the canine fossa
of the maxilla, just below the infraorbital foramen (Figure 14.49).
It lies deeply beneath the upper lip levators and the zygomaticus
complex. Its muscle fibers travel downward into the modiolus and
then interdigitate with those muscle fibers of the zygomaticus
major while wrapping around the oral commissure also to inter­
digitate with the fibers of the orbicularis oris and the depressor
anguli oris. The levator anguli oris then inserts into the overlying
skin at and just below the angle of the mouth and the lower portion
of the nasolabial sulcus. It raises the lateral aspect of the upper lip,
and the corners of the mouth when smiling or laughing. In some
patients, it also deepens and shifts the contour of the lower naso­
labial sulcus.
The preceding group of four upper lip levators was previously identi­
fied as the quadratus labii superioris, which, when contracted, was felt
to cause the nasolabial sulcus to deepen. The quadratus labii superi­
oris was described as comprising four muscle heads: the angular head
or the LLSAN, the infraorbital head or the LLS, the zygomatic head or
the zygomaticus minor, and the canine head or the levator anguli oris
(Figure 14.50). Because of the intricacies of the mid face functional anat­
omy necessary for complex deliberate and subtle involuntary and spon­
taneous fine facial mimetic movement, injecting OnaBTX-A anywhere
in the mid face must be performed with absolute precision and accuracy.
Dilution (See Appendix 3) When Treating Nasolabial Folds
Injecting minimal volumes of OnaBTX-A in this area is of paramount
importance so as not to have unintended diffusion of the OnaBTX-A
affect the surrounding muscles of the midface. Therefore, a 100 U vial
of OnaBTX-A should be reconstituted with only 1 mL of normal saline.
Dosing: How to Correct the Problem (See Appendix 4) (What to
Do and What Not to Do) When Treating Nasolabial Folds
Injecting 1 U and not more than 2 U of OnaBTX-A into the middle
of the nasofacial angle just lateral to the upper border of the ala nasi
will weaken the lateral fibers and some of the medial fibers of the
LLSAN and flatten the upper medial aspect of the nasolabial fold
2
6
5
4
1
9
7
8
10
3
Figure 14.49  The levator labii superioris alaeque nasi is divided into two separate
bundles of muscles distally; the medial bundle inserts into the skin over the ala nasi
and interdigitates with the fibers of the anterior and posterior dilator naris, and the
lateral bundle inserts into the skin and mucosa of the center of the upper lip inter­
digitating with fibers of the orbicularis oris. The levator labii superioris, widest of all
the lip levators, is a deeper muscle originating from the maxilla at the lower margin
of the orbit, just above the infraorbital foramen and under the orbital orbicularis
oculi and inserts directly into the skin of the central and lateral aspect of the upper
lip, interdigitating with the orbicularis oris. The levator anguli oris lies deep to all
the muscles of the midface, originates in the canine fossa of the maxilla, travels
downward into the modiolus, interdigitating with the other modiolar muscles, and
inserts into the overlying skin at and just below the angle of the mouth and the lower
portion of the nasolabial sulcus. 1, Anomalus nasi; 2, levator labii superioris alaeque
nasi; 3, levator alae nasi; 4, levator labii superioris; 5, levator anguli oris; 6, trans­
verse nasalis; 7, compressor narium minor; 8, anterior dilator naris; 9, ­posterior
dilator naris; 10, orbicularis oris.

Botulinum Toxins in Clinical Aesthetic Practice
218
(Figures 14.51 and 14.52). While sitting or in a semi-reclined position,
ask the patient to sneer or lift the upper lip forcibly in an upward direc­
tion to expose the upper central teeth as one does when sneering or
expressing abhorrence, disgust, or repugnance (Figure 14.53). With
the index finger of the nondominant hand directly over the nasofa­
cial angle and palpating the area gently, one will feel the contracture
of muscle fibers as the patient repeats the sneer maneuver. With the
needle pointed perpendicularly to the surface of the skin, advance it
approximately 3–5 mm deep and just before contacting bone as not
to inflict additional undue pain on the patient. Inject only 1 or 2 U
of OnaBTX-A directly into the thickest bulge of muscle contraction
(Figure 14.54). Depending on the position and depth of the nasola­
bial sulcus and the height of the nasolabial fold, the bulge of muscle
contracture palpated may actually correspond to the interdigitat­
ing lower fibers of the LLS and zygomaticus minor together with the
lower lateral labial fibers of the LLSAN55 (Figure 14.55). This also is
the same technique used to inject OnaBTX-A to reduce a gummy
smile (see Gummy Smile below). These injection techniques should
be performed only by the very experienced physician whose patient
possesses nasolabial folds that are deep and become exaggerated with
a simple upward movement of the upper lip, as in sniffing, sneering,
and smiling (Figure 14.56). Proper patient selection is of paramount
importance because untoward sequelae resulting in a lack of control
of essential buccal sphincteric functions can occur very easily and
be devastating to the patient. The use of electromyographic guidance
when treating this area can be helpful to the novice injector.1
For those patients who produce innumerable wrinkles of the mid
cheek with smiling or squinting, an intradermal injection of 1–2 U
of OnaBTX-A near the origins of the zygomaticus complex along the
inferior lateral margin of the zygomatic arch at the inferior border of
the orbital orbicularis oculi of the lower eyelid can achieve an addi­
tive effect of diminishing lower lateral canthal rhytides along with
effacing nasolabial folds (Figure 14.57).56 Depending on the idiosyn­
cratic anatomy of a particular individual, the shape of the face, and
the strength of the muscles, it might be necessary to administer one,
two, or multiple injections of OnaBTX-A, each over the mid to lat­
eral malar prominence, to obtain the consistent results desired (see
Chapter 17 by Kyle Seo on intradermal injections).5,56,57 This tech­
nique always is accompanied by a drop of the upper lip or a reduc­
tion in the lateral excursion of the oral commissures especially when
smiling, laughing, or speaking.
Shao-Ping et al. injected a total of 20–25 U of OnaBTX-A intrader­
mally into the entire face lateral to the nasolabial fold, including the
temples and cheeks from the infraorbital area to the jawline at 1 cm
(b)
1
2
3
4
2
1
3
4
(a)
Figure 14.50  Quadratus labii superioris, (a) viewed from the side and (b) viewed from the front. 1, levator labii superioris alaeque nasi; 2, levator labii superioris; 3, zygo­
maticus minor; 4, levator anguli oris.
(a)
(b)
Figure 14.51  (a, b) • marks the point where 1 U of OnaBTX-A was injected into this 53-year-old to diminish the depth of the nasolabial sulcus. Note the elongation of the
upper lip, flattening of the philtrum and thinning of the vermillion in this patient at rest.

14.  cosmetic uses of botulinum toxin a in the mid face
219
intervals.10,58 A 100 U vial of OnaBTX-A was reconstituted with 10 mL
of normal saline to achieve a concentration of 10 U of OnaBTX-A
for each 1 mL of solution. Each site on the face was injected with
0.02 mL of OnaBTX-A solution. This technique of microBOTOX (also
known as mesoBOTOX) injections is very popular in Far East Asia
where a subtle lifting and diminution of the fine facial wrinkling is in
demand (see Chapter 17 by Kyle Seo on micro-intradermal injections
of BoNT-A).
Outcomes (Results) (See Appendix 5) When Treating
Nasolabial Folds
There have been a few attempts to establish a fail-safe technique in
which some of the upper lip levators could be treated with OnaBTX-A
to reduce a deep nasolabial sulcus and fold without attendant adverse
effects on lip function and symmetry. If one considers the LLSAN
the principal muscle that creates the upper medial aspect of the naso­
labial fold, and the other central and lateral lip levators (the LLS,
zygomaticus complex, levator anguli oris, and risorius) responsible
for deepening the mid and lower nasolabial sulcus when they con­
tract, then precisely placed low-volume injections of concentrated
OnaBTX-A should be able to reduce the appearance of the nasolabial
fold and the depth of its sulcus. Because this is not the only or pri­
mary function of these muscles, injections of OnaBTX-A can unwit­
tingly produce secondary changes that interfere with and diminish
the primary functions of these muscles, that is, elevating the upper
lip and laterally abducting the corners of the mouth, which are nec­
essary movements when one speaks, smiles, laughs, yawns, eats,
drinks, or forcibly breathes by mouth. Nasolabial fold effacement and
its accompanying side effects can last up to 3 months or as long as the
OnaBTX-A treatment is effective.
Petchngaovila describes an intradermal injection technique of
highly diluted OnaBTX-A, which relaxes what she considers the major
depressors of the face (i.e., platysma and lateral orbital orbicularis
oculi) and allows the levators of the mid face (zygomaticus complex,
LLSAN, LLS and levator anguli oris) and lateral frontalis to reverse
the sagging and wrinkling of the upper and mid face.57 According to
Petchngaovila, this intradermal mid face lifting realigns the imbal­
ance of the muscles of the midface by weakening the downward pull
of the depressors (platysma, lateral fibers of the orbital orbicularis
oculi) and allowing the levators of the mid face and lateral frontalis
to contract and lift the skin in a compensatory fashion. This treatment
requires not only multiple repeat injections before obvious results are
produced, but also frequent maintenance injections every 2–3 months.
This procedure is best done for sheet-like muscles rather than for
individual muscle bundles, and when muscles are flaccid and poorly
defined. This technique also is best suited for older patients with loose,
lax skin who want to realign and uplift their mid face, diminish the
wrinkling of their cheeks, and soften the nasolabial folds (Figures
14.58 through 14.60) (see Chapter 17 by Kyle Seo on intradermal injec­
tions). With the possible future introduction of topical preparations of
BoNT-A, intradermal microinjections of BoNTs may eventually wane
in popularity. (see Chapter 4 by Richard Glogau).
Complications (Adverse Sequlae) (See Appendix 6) When Treating
Nasolabial Folds
Just 1–3 U of OnaBTX-A into each lip levator complex in the lower
nasofacial sulcus will collapse the upper extent of the nasolabial
fold and also elongate the upper lip, with fairly long-lasting results.1
However, injecting this area can result in a flat mid face with elonga­
tion of the upper lip, effacement of the philtrum, diminution of the
fullness and narrowing of the upper lip vermillion (see Figure 14.51).
This is an appearance that is not well accepted by most individuals,
especially those who already have a naturally longer, thinner upper
lip (Figure 14.61). Overzealous treatment of this area can result in an
asymmetric smile and a ptotic upper lip, causing drooling and fluid
incontinence when drinking from a glass or cup. It also can result in
biting the upper lip when chewing. In most patients, these nasolabial
lines are best treated with soft tissue fillers, implants, or surgical rhyt­
idectomy, and not with OnaBTX-A.3 (See Chapter 7 by Alastair and
Jean Carruthers).
Injecting OnaBTX-A any lower than the upper alar facial bor­
der, that is, closer to the alar labial sulcus or along the nasal sill, can
1
Figure 14.52  • marks the point where 1–2 U of OnaBTX-A can be injected to
weaken the lateral labial and some of the medial nasal fibers of the levator labii
superioris alaeque nasi to diminish the depth of the nasolabial fold.
Figure 14.53  Elevation of the upper lip when sneering, sniffing, or smiling will
contract the levator labii superioris alaeque nasi as well as the levator labii supe­
rioris and the zygomaticus minor in most patients. Note the deep nasolabial fold
and gummy smile.

Botulinum Toxins in Clinical Aesthetic Practice
220
produce a weakening of the central upper lip levators and the orbicu­
laris oris resulting in an inability to elevate the upper lip, elongating
its overall dimensions. This is a common technique used to drop the
upper lip and correct a gummy smile, but is not appropriate in most
patients just seeking a reduction in the depth and fullness of their
nasolabial folds (see Gummy Smile below).
Usually, injecting only 1–2 U of OnaBTX-A intradermally away
from the mouth, and near the origins of the zygomaticus major and
minor and LLS at the inferior border of the lateral orbital orbicularis
oculi, can help both diminish the nasolabial fold and efface the lower
lateral canthal wrinkles and lower lateral cheek rhytides. This tech­
nique usually is accompanied by a reduction in the strength of the
upper lip sphincter competence and smile symmetry.3,5 It is extremely
important, however, that minimal volume of OnaBTX-A is injected
deeply and precisely into the fibers of the targeted muscles, to lightly
weaken and not paralyze them. Even with a light weakening of the
LLS and the zygomatic complex, a certain amount of lip ptosis will
occur, and is actually expected. This should be discussed with the
patient before treatment, and should not be considered a true adverse
outcome or complication (Figures 14.51 and 14.61)2,59 (see Dr. Seo’s
Chapter 17 for similar results with the microinjection technique).
In older patients who have a large amount of excessive fat deposition
or ptotic malar fat along with redundant skin lateral to the nasolabial
sulcus, weakening the central upper lip levators will have no effect on
(a)
(b)
Figure 14.54  (a, b) Injecting OnaBTX-A should be performed intramuscularly with the needle perpendicular to the skin surface.
(a)
(b)
Figure 14.56  This 51-year-old patient has deep nasolabial folds at rest (a), which are exaggerated by smiling (b). Note the inversion and foreshortening of the upper lip with
smiling.
1
2
3
Figure 14.55  • marks the point where 1–2 U of OnaBTX-A can be injected to weaken
the levator labii superioris and zygomaticus minor along with the levator labii supe­
rioris alaeque nasi to diminish the nasolabial fold. 1, levator labii superioris alaeque
nasi; 2, levator labii superioris; 3, zygomaticus minor.

14.  cosmetic uses of botulinum toxin a in the mid face
221
the extent and depth of the nasolabial folds. The nasolabial folds might
even be enhanced if the lateral upper lip levators are weakened, caus­
ing a reduction in the lateral muscle support, which in turn will allow
the ptotic fat and redundant skin to sag even more so. On the other
hand, in younger patients (i.e., those in their early thirties to late fif­
ties) with good cutaneous elasticity and soft tissue support, much of
the appearance of the nasolabial fold is caused by mimetic muscle con­
traction, the bulk of which can be attributed to the LLSAN. When this
muscle is weakened in younger persons, the nasolabial fold is dimin­
ished, usually uneventfully. Attempting to weaken some of the other
upper lip levators may cause undesirable sequelae, for example, upper
lip ptosis, buccal asymmetry, and even oral sphincter incompetence.
For example, also weakening the zygomaticus muscles can soften the
nasolabial folds, but the smile may be changed, reducing the extent of
the upward and lateral excursion of one’s smile. However, for those
patients displaying an excessive amount of gingiva when smiling or
laughing, weakening of the central upper lip levators may actually be
desirable because it can reduce the full upward movement of the upper
lip that overexposes the crown and gums of the upper incisors and
canines (see Gummy Smile below).
Injecting OnaBTX-A in the mid face in an attempt to diminish the
nasolabial folds and to eliminate the random wrinkling of the lateral
aspect and center of the cheeks produced by squinting or smiling
should only be attempted by the most experienced physician injec­
tor.6 Selecting the right patient can be more important than any
other aspect of an OnaBTX-A injection technique. Understanding
how certain facial and cheek wrinkles and folds are produced, and
how to palpate and identify the correct target muscles for injection,
is the key to success or failure. Attempting to reduce midcheek wrin­
kling and nasolabial folds with injections of OnaBTX-A can result
in not only a flattening of the nasolabial fold, but also an overall
flattening of the cheek and an elongation of the upper lip, an ecla­
bion or lip ptosis as well as lip asymmetry and lack of oral sphinc­
ter control.57 For these reasons, it is probably most advisable not to
treat this area of the mid face with OnaBTX-A unless the patient
is willing to endure unconditionally the expected and inadvertent
sequelae. Subcising deeply adherent nasolabial sulci, injecting them
with a soft tissue filler and resurfacing the cheeks by chemical peel­
ing, dermabrasion, fractionated laser ablation or deep tissue non-
ablative laser remodeling is probably a more reliable way to address
these problems and produce consistent, longer lasting results.5
Treatment Implications When Injecting Nasolabial Folds

1. Successful treatment of the nasolabial fold is absolutely depen­
dent on proper patient assessment of what is physically causing,
and what muscles, are actually creating and exaggerating the
nasolabial fold and deepening the sulcus.

2. The levator labii superioris alaeque nasi is usually the muscle
primarily responsible for the creation and enhancement of the
upper, medial portion of the nasolabial sulcus and fold.

3. Nasolabial folds are best reduced by injections of soft tissue fill­
ers, subcision, implants, and surgical rhytidectomy rather than
with injections of OnaBTX-A.
*
*
Figure 14.57  Intradermal injection of 1–2 U of OnaBTX-A (•) at the lateral zygo­
matic arch near the origin of the zygomaticus complex can diminish lower crow’s
feet lines, mid cheek wrinkles and help efface the upper and mid nasolabial sulcus
and fold. Depending on the individual’s anatomy, shape of face and strength of
the muscles, a second injection point (*) might be necessary to produce the same
results. See Chapter 17 on microinjections of BoNTA.
(a)
(b)
(c)
Figure 14.58  This 40-year-old patient is seen (a) before, (b) 2 weeks after intramuscular treatments, and (c) 10 weeks after intradermal injections of BoNTA, giving her a
slight lift of the total face. (Courtesy of Chariya Petchngaovila, MD)

Botulinum Toxins in Clinical Aesthetic Practice
222
(a)
(b)
Figure 14.59  This 61-year-old patient is seen (a) before and (b) 2 weeks after intradermal injections of OnaBTX-A. Note the overall appearance of a “face lift.” (Courtesy of
Chariya Petchngaovila, MD)
(a)
(b)
Figure 14.60  This 33-year-old patient is seen (a) before and (b) 10 days after intradermal injections of OnaBTX-A, giving her the appearance of a “facial lift.” (Courtesy of
Chariya Petchngaovila, MD)

14.  cosmetic uses of botulinum toxin a in the mid face
223

4. In the properly selected patient injections of 1–2 U of OnaBTX-A
can be given in the upper alar facial sulcus in an attempt to flat­
ten the nasolabial fold.

5. Injections of OnaBTX-A too low along the alar facial angle will
produce an elongation or ptosis of the upper lip, an asymmetric
smile, and functional incompetence of the oral sphincter.

6. Injections of OnaBTX-A too lateral to the nasofacial angle will
produce an overall flattening of the midcheek and a drop in the
soft tissue support of the malar fat pad.

7. In the properly selected patient, a combination of injections of
OnaBTX-A and either soft tissue fillers or some form of surgical
intervention or both will produce longer lasting results than if the
nasolabial folds were to be treated solely with either alone.
EXCESSIVE MAXILLARY GINGIVAL DISPLAY (GUMMY SMILE)
Introduction: Problem Assessment and Patient Selection
Some individuals tend to reveal an excessive amount of their maxillary
gingival mucosa when they smile or laugh, which is euphemistically
known as a “gummy smile.” This commonly is seen as a familial trait,
which can be particularly disconcerting in women or men who display
this type of smile. Most of the time, since this is a source of consid­
erable embarrassment, one can observe these individuals concealing
with their fingertips or hands the appearance of their gums and teeth
when they smile or laugh. Also, while speaking in an animated fashion
which causes them to smile or laugh during conversation, they can
be seen covering their mouths in whatever way possible. No matter
how hard they try, it is impossible for these individuals to smile or
laugh without revealing their maxillary gingiva. Consequently, they
attempt only to smile partially when being photographed or during
social interactions which creates a certain amount of anxiety for those
who are more self-conscious.60 These individuals also tend to have
sharply defined nasolabial folds with deep furrows (see Figure 14.53)
(see Nasolabial Folds above).
Some patients, in conjunction with the inadvertent shortening of
their upper lip causing an exaggerated gingival smile, also are plagued
with exhibiting an involuntary lowering of the tip of their nose (see
nasal tip ptosis above). There are still others who also form a transverse
furrow across the philtrum of their upper lip when they speak, laugh,
or smile. Occasionally, the same person exhibits a combination of all
these idiosyncratic anatomical changes which has been identified by
Cachay-Velasques as the rhinogingivolabial syndrome34,61 (see nasal
tip ptosis above). A horizontal furrow across the upper lip usually is
seen in older individuals or in those whose photodamaged skin has
reduced elasticity and soft tissue bulk, causing the lax upper lip skin
to fold easily into a deep horizontal upper lip furrow (Figure 14.62).
Circumoral vertical wrinkles that radiate away from the vermilion
with every movement of their lips are also frequently seen in individu­
als who have a long history of smoking tobacco (see perioral lip lines
in Chapter 15).
Functional Anatomy (See Appendix 2) of an Excessive Maxillary
Gingival Display (Gummy Smile)
The essential components of a smile are the teeth, the gingiva, and
the lips that surround them.62 The aesthetics of an “ideal smile” vary
according to idiosyncratic structural and topographic peribuccal
anatomy predicated on a person’s gender, familial traits (genotypic
and phenotypic characteristics), race, and ethnicity. An atttractive
smile is influenced by the color, shape (silhouette), and the position
of the teeth in the mouth, along with the symmetrical architecture
and periodontal health of the gums and the free gingival margin. The
lips frame a smile and the outline of the scalloped gingival margins
should be parallel to both the incisal edges of the teeth and the cur­
vature of the lower lip. An attractive smile possesses symmetrical
gingival margins of the central incisors while the more lateral teeth
can have a certain amount of asymmetry.63 When analyzing a smile,
a certain amount of gingival exposure can be considered aestheti­
cally pleasing and even youthful. The length of a normal upper lip
measured from the subnasale to the lower border of the upper lip is
20–24 mm in young adults and increases in length with age (Figure
14.63). A maxillary central incisor display at rest averages 3–4 mm
in young women and 2 mm in young men, and decreases with age
(Figure 14.64).
In general, an attractive smile has been identified by many authors
as having the following characteristics:63

1. Minimal gingival exposure

2. Symmetrical display and harmony between the maxillary gingi­
val line and the upper lip

3. Healthy gingival tissue filling the entire interproximal spaces

4. Harmony between the anterior and posterior segments (grada­
tion principle)

5. Teeth in correct anatomical form, proportion, and position

6. Proper color and shade of the teeth
(a)
(b)
Figure 14.61  A 29-year-old patient smiling (a) before and (b) 2 weeks after a treatment with OnaBTX-A to efface a deep nasolabial fold. Note the slight upper lip ptosis
that is unavoidable with this treatment. Note the upward direction of the commissures, which is created by the untreated and unopposed action of the zygomaticus major,
levator anguli oris, and risorius.

Botulinum Toxins in Clinical Aesthetic Practice
224

7. Lower lip parallel to the incisal edges of the maxillary anterior
teeth and to the imaginary line passing through the contact
point of these teeth
A smile is formed in two dynamic stages.64 In the first dynamic
stage of a smile the upper lip is lifted toward the nasolabial fold by the
contraction of the levator muscles originating in the fold and insert­
ing into the upper lip. The fibers of the medial levators (LLSAN, LLS,
zygomaticus minor, central orbicularis oris, and in some individuals,
the depressor septi nasi) raise the lip upward over the anterior teeth
while the fibers of the lateral levators (LLS, zygomaticus major, levator
anguli oris, and lateral orbicularis oris, and in some individuals, the
risorius) raise the lip laterally and slightly upward above the poste­
rior teeth. There is then self-limiting resistance at the nasolabial fold
because of cheek fat.
The second dynamic stage of a smile involves further lifting of the
lip and the nasolabial fold by three bundles of muscle: (1) the LLS of
the upper lip, originating at the infraorbital region; (2) the zygomati­
cus major, and (3) superior fibers of the buccinators. Often, squinting
accompanies the final stage of smiling. It represents the contraction
of the perioral musculature (zygomaticus major and minor, LLSAN,
and LLS) that interdigitates with the muscle fibers of the lower orbital
orbicularis oculi that supports maximum upper-lip elevation through
the fold63,64 (see nasolabial folds above).
The “smile line” is the position of the upper lip to the maxillary inci­
sors and gingiva reached during a naturally full smile. Someone with
a “low smile line” exposes less than 75% of the crown height of the
maxillary anterior teeth. Those with an “average smile” display 75%
to 100% of the maxillary crown height and no more exposure than
1–2 mm of upper gum mucosa.65 Someone with a “high smile line”
reveals the entire crown of the tooth and usually over 2 mm of con­
tiguous maxillary gingiva64,66 (Figure 14.65). Generally, men exhibit a
lower smile line and less interlabial excursion than women who char­
acteristically exhibit a higher smile line.64,67,68
There are three main reasons for a high “gingival smile,” also known
as a “gummy smile”; they include vertical maxillary excess, altered or
delayed passive eruption, and hyperkinetic upper lip levators.62 It is
extremely important to correctly assess and diagnose clinically why a
(a)
(b)
Figure 14.63  The length of a normal upper lip measured from the subnasale to the lower border of the upper lip is 20–24 mm in young adults (a) and increases in length
with age as seen in this 67-year-old patient (b).
(a)
(b)
Figure 14.62  (a, b) A transverse rhytide is seen across the philtrum of the upper lip at rest, which is intensified with smiling in this 68-year-old non-smoker with extensive
photodamage. Note the minimal gummy show, deep nasolabial folds and furrows, widening of the alar base, and the slight nasal tip downward rotation with smiling. Her
shallow vertical lip lines are due to sun damage and aging and not to tobacco smoking.

14.  cosmetic uses of botulinum toxin a in the mid face
225
person may possess a gummy smile before deciding on, and initiating
any treatment. Incorrect diagnoses and treatment plans are frought
with failure, disappointment, and adverse sequelae.
“Vertical maxillary excess” is identified clinically as an elongation
of facial height created by a hyperplastic overgrowth of the maxillary
skeleton resulting in an excessive vertical length of the maxilla, oth­
erwise known as “long face syndrome”.63,66,69,70 An increase in facial
height appears mainly in the lower half of the face. This skeletal dys­
plasia causes the teeth to be positioned farther away from the skeletal
maxillary base, exposing the gingiva below the inferior border of the
upper lip. It also causes the lower lip to cover the incisal edges of the
maxillary canines and premolars. Most often the length of the upper
lip is normal even though clinically it may appear relatively shorter.63
Depending on the amount of skeletal hyperplasia and gingival dis­
play present, which can reach over 8 mm of gingival exposure, the
only corrective solution might be cephalometric analysis and possible
bone resection, or orthognathic surgical realignment with or without
periodontal and restorative therapy.1 Hence, referral to the appropri­
ate dental and maxillofacial specialists is advisable.
Another frequently encountered dental condition to be identified
when determining the reason for someone’s gummy smile is the short
square tooth with a short crown height (visible tooth length) with or
without malpositioning of the incisors.63 The difference between the
anatomical crown height of a tooth and its clinical crown height will
help determine whether the short crowns of the anterior maxillary
teeth are a result of the natural wearing of the incisal surface of a tooth
or the position of the gingival margin over the coronal aspect of the
teeth; the anatomical crown height is the distance between the incisal
edge of a tooth to the cementoenamel junction, whereas the clinical
crown height is the distance from the incisal edge of a tooth to the free
gingival margin63 (Figure 14.66). When the gingival margin recedes
at the apical aspect of a completely erupted tooth to the level of the
cementoenamel junction, this is known as “passive eruption.” It is the
natural physiologic progression of the growth and development of a
normal tooth and it can continue well into the third decade of life.
When the gingival margins are delayed or completely fail to recede
to the level of the cementoenamel junction this is called “altered” or
“delayed passive eruption,” which can be found in 12% of the gen­
eral population (Figure 14.67). Altered passive eruption is an aber­
ration in normal tooth development, and may involve one or many
teeth where a large portion of the dental crown remains covered in an
overgrowth of gingiva. Characteristically, the gingival margin above
the tooth appears flat with a minimal degree of scalloping or arching.
Affected teeth appear short and square, instead of elliptical and ovoid
in form. When this excess amount of gingiva is observed below the
inferior border of the upper lip, the result is an “excessive maxillary
gingival display” or a “gummy smile.” If a physician is unaware of this
condition when evaluating someone with a gummy smile during the
pre-injection assessment, the physician injector can be easily misled
into misdiagnosing a “high smile line” when in reality the presenting
patient has a normal lip line or an otherwise “medium smile line”’
which does not require treatement with a BoNT but instead will ben­
efit from a referral to a periodontist a referral to a periodontist for
gingivoplastic treatment.
The third most common cause for a gummy smile is the exces­
sive contraction of the upper lip levators, producing an exaggerated
exposure of the maxillary gingiva on smiling or laughing.67,68 This can
occur in conjunction with or without an increase in the interlabial
space at rest. Prior to the advent of the BoNTs, various perioral mus­
cular resection procedures (myotomies and myectomies of specific
mimetic muscles) were devised to eliminate or at least diminish the
causative muscular contractions that excessively elevated the upper
lip and produced a gummy smile. Now various injection techniques
of BoNT have superseded and replaced the need for the more inva­
sive and morbid surgical procedures of treating gummy smiles due to
hyperkinetic muscular activity.71 Another not so common cause of a
gummy smile is a genetically short upper lip that is less than 15 mm in
height measured from the subnasale to the lower border of the upper
lip (Figure 14.68). Even though the same treatment used for hyperac­
tive lip levators causing a gummy smile can be used to treat a gummy
smile that results from a congenital short upper lip, in reality the only
suitable treatment for this type of a congenital defect is an appropriate
surgical intervention.
Functionally, according to Rubin, there are three different patterns
of smiles that can be identified when a person smiles.72,73 The first and
most commonly encountered type of smile (67% of the patients stud­
ied) is when the zygomaticus major dominates the movement of the
lips. This is called the “Mona Lisa” or “commissural” smile and is ini­
tiated with a sharp elevation and outward pull of the corners of the
mouth and then a soft elevation of the center of the upper lip, revealing
approximately 80% of the incisors (Figure 14.69). This type of smile is
produced predominantly by the pull of the zygomaticus major.
The “canine” or “cuspid” smile is the second most commonly identi­
fied smile pattern (35% of the patients studied) and is characterized by
a high elevation of the center of the upper lip, exposing the canine teeth
first before the rest of the upper lip is elevated (Figure 14.70). The canine
smile can produce anywhere from a partial central dental reveal to an
exaggerated full denture show with a certain amount of gingival expo­
sure. This pattern of smile is produced predominantly by the contrac­
tion of the LLS elevating the upper lip. When the contraction of the LLS
is intense and severe, a gummy smile results (Figure 14.71).
The third and least commonly seen smile pattern is the “full den­
ture” or “complete” smile, which was seen in about 2% of the patients
studied. The full denture smile is characterized by the simultaneous
separation of both the upper and lower lips in which both the upper
(a)
(b)
Figure 14.64  Maxillary central incisor display with someone at rest is 3–4 mm in
young women as seen in a 31 year old patient (a), and 2 mm in young men as seen
in a 34-year-old patient (b), and decreases with age.

Botulinum Toxins in Clinical Aesthetic Practice
226
(a)
(b)
(c)
Figure 14.65  The smile line is the position of the upper lip and its relationship, when smiling, with the maxillary anterior incisors and gingiva. There are three types of
smiles. (a) A person with a low smile line reveals less than 75% of the crown height when smiling; (b) a person with a medium or average smile line reveals 75%–100%
of the maxillary crown height; (c) a person with a high (or “gingival”) smile line reveals 2–3 mm or more of upper gum when smiling and is often referred to as having a
“gummy smile.”
1
2
3
6
4A
4B
5
Figure 14.66  Anatomy of a “gummy smile”: 1, excess amounts of gingiva in delayed
or passive eruption; 2, normal gingival margins; 3, alveolar bone; 4A, clinical
crown; 4B, anatomical crown; 5, cementoenamel junction; 6, root.
Figure 14.67  Altered or delayed “passive eruption” is an aberration in normal
tooth development, involving many teeth where a large portion of the dental
crown remains covered in an overgrowth of gingiva and the gingival margin above
the tooth appears flat with a minimal degree of scalloping or arching. Affected
teeth appear short and square, instead of elliptical or ovoid in form. This excess
amount of gingiva seen below the inferior border of the upper lip, results in an
“excessive maxillary gingival display” or a “gummy smile.”

14.  cosmetic uses of botulinum toxin a in the mid face
227
maxillary and lower mandibular dentures have partial or full expo­
sure. This type of smile is the result of the contraction of all the upper
lip levators and lower lip depressors around the mouth all at the same
time (Figure. 14.72).
Commonly found accompanying a naturally occurring or an
exaggerated canine smile (i.e., a “gummy smile”) are individuals
with deep nasolabial furrows and highly mounded nasolabial folds
(Figures 14.61, 14.65c, 14.68b and 14.71b). These two conditions usu­
ally are found together. Contraction of the LLSAN creates an ascend­
ing steep medial nasolabial fold while lifting the central upper lip a
few extra millimeters in conjuction with the LLS. The result is a high
smile line and exposure of the alveolar gingiva (i.e., a gummy smile).
Generally, an unattractive “gummy smile” reveals more than 2–3 mm
of ginigiva above the central maxillary incisors. Most orthodonists
and dentists prefer to see the lip elevation stop at the gingival margins
of the maxillary incisors with a posed smile, but minimal amounts of
gingiva can show with an exaggerated smile, depending on the indi­
vidual’s physiognomy. The aesthetics of a natural smile thus can vary
from person to person depending on many different perceived subtle
factors, including overall skeletal shape, ethnic proportions, and
muscle configuration and variations in facial soft tissue and mimetic
muscle composition and activity.60
Gummy smiles have been classified by Mazzuco and Hexsel as
anterior, posterior, mixed or asymmetric.74 They identified an ante­
rior gummy smile as displaying more than 3 mm of maxillary gin­
giva over the area between the upper canine teeth and attributed it
to the action of the LLSAN. A posterior gummy smile was identified
as displaying more than 3 mm of gingiva over the area posterior
to the upper canine teeth, but with normal anterior maxillary gin­
gival exposure of less than 3 mm. It was attributed to the action of
the zygomaticus muscles. A mixed gummy smile displays excessive
amounts of gingiva both in the anterior and posterior aspects of the
maxillary gingiva. This was attributed to the variable actions of any
one of a combination of the different levator muscles which produce a
smile: the LLSAN, zygomaticus major and minor, as well as the LLS,
levator anguli oris, and possibly the risorius. When individual central
maxillary retractors (e.g., the LLSAN or the zygomaticus major) are
hyperkinetic, asymmetric gummy smiles usually are not uncommon
(Figures 14.73 and 14.74).
Dilution (See Appendix 3) When Treating Excessive Maxillary
Gingival Display (Gummy Smile)
Injecting minimal amounts of low-volume OnaBTX-A in the mid face
is of paramount importance. The least amount of unintended diffu­
sion of OnaBTX-A in the stratified lamellae of the different muscle
bundles of the perioral area can be disastrous to the overall therapeu­
tic success and cosmetic appearance of the patient. The reputation of
a physician injector who treats the mid face is tenured in the aesthetic
outcomes of his or her skillful injection techniques. Therefore, the
most experienced and qualified physicians treating this area of the
face will reconstitute a 100 U vial of OnaBTX-A with only 1 mL of
normal saline.
(a)
(b)
Figure 14.68  (a, b) Both these patients have a genetically short upper lip, measuring less than 15 mm in height measured from the subnasale to the lower border of the
upper lip.
(b)
(a)
Figure 14.69  (a) The most common type of smile, the Mona Lisa smile, is produced primarily by the pull of the zygomaticus major. (b) Patients with a Mona Lisa or com­
missural smile after being treated with OnaBTX-A for a high lip line have found themselves with a “joker-like” smile, because the central lip levators were weakened while
the lateral lip levators were not.

Botulinum Toxins in Clinical Aesthetic Practice
228
Dosing: How to Correct the Problem (See Appendix 4) (What to
Do and What Not to Do) When Treating Excessive Maxillary
Gingival Display (Gummy Smile)
As one ages, the upper lip becomes flaccid and lengthens with time,
making noninvasive treatments of a gummy smile with OnaBTX-A
a more preferred option over the morbidity, long recovery time, and
high cost of more invasive bone or muscle resection surgery that is
frought with scar contracture and protracted regeneration of muscle
activity. However, when deciding on an injection pattern for a patient
with a gummy smile, it is of utmost importance to select the proper
candidate prior to treatment. Of all the patients Kane treated for an
excessive maxillary gingival display, he discovered that only those
patients with a canine or cuspid type smile were the most appropri­
ate candidates for injections of OnaBTX-A.51,52 These patients had the
best outcomes and were the most satisfied with their reults.71
To nonsurgically elongate the upper lip, especially during a smile,
the central upper lip retractors (LLSAN and LLS) need to be gently
relaxed (not paralyzed) with injections of OnaBTX-A. This can be
Figure 14.71  An exaggerated gummy canine smile in this 23-year-old patient. Note the deep nasolabial folds and furrows that often accompany a gummy smile.
(a)
(b2)
(b1)
Figure 14.70  (a) The canine smile exposes the canine teeth before the rest of the upper lip is elevated. (b1,b2) An exaggerated canine smile in a younger and older patient.

14.  cosmetic uses of botulinum toxin a in the mid face
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accomplished with the patient in a sitting or semireclined position.
Then palpate the nasomaxillary groove with the fingertip of the index
finger of the nondominant hand, until the fingertip pad straddles the
lower lateral aspect of the alar facial sulcus and the superior edge of
the maxillary alveolar process. Excessive pressure with palpation in
this area can cause some discomfort to the patient, so this maneu­
ver should be done as gently and expeditiously as possible. As the
patient smiles and with the index finger in this position, contraction
of the LLSAN can be felt. At the point of maximum thickness of the
muscle, insert the needle perpendicularly to the surface of the skin
and deeply into the nasofacial groove for about 3–5 mm. Inject 1–2 U
of OnaBTX-A intramuscularly and just above the periosteum of the
canine fossa (Figure 14.75). An additional unit of OnaBTX-A may be
required if the central lip levators are very strong and the center of the
upper lip is lifted extremely high. Remember to reserve this injection
technique only for those patients with a canine or cuspid type smile
who have an exaggerated gingival display, and in whom the upper
lip retractors can be palpated.51,52,60,75 The direct upper lip retractors
are the LLSAN, the LLS, and, according to different live patient and
cadaver dissection studies, the zygomaticus minor and central orbi­
cularis oris. Depending on the overall facial shape and the variations
of muscular activity, the indirect upper lip retractors—that is, those
which pass through the modiolus first before inserting into the lips—
may also play a role in an excessive maxillary gingival display. They
include the zygomaticus major, levator anguli oris, lateral orbicularis
oris, and risorius.76 It is the subtle variations in muscle location and
activity that account for the variations in individual idiosyncratic
facial expressions and the differences in treatment response and final
outcome with OnaBTX-A even when the injection technique is impec­
cable. Also, remember that injecting OnaBTX-A at this site may reduce
the height and extent of the nasolabial fold by weakening the LLSAN
as well as the LLS and zygomaticus minor (Figure 14.76). When cor­
recting only a central gummy smile, it is best to avoid weakening the
more laterally located lip levators, that is, zygomaticus major, levator
anguli oris, and risorius; otherwise, either an adynamic or asymmetric
smile can result. Weakening only the central upper lip levators with­
out affecting these lateral upper lip levators allows the lateral levators
full and uninhibited movement during a smile. Focused central upper
lip weakening can be enhanced by also treating the depressor anguli
oris with OnaBTX-A, thereby removing any additional antagonistic
lateral lower lip depressor action against unnecessary and uninten­
tional weakening of the lateral upper lip levators.
(a)
(b)
Figure 14.72  (a) The full denture smile is a result of the contraction of all the upper lip levators and lower lip depressors around the mouth, all at the same time, and is
characterized by the simultaneous partial or full exposure of both upper and lower dentures. (b) Note a slight ptosis of the upper left quadrant.
Figure 14.73  Hyperkinetic central upper lip levators create a slight gummy com­
missural or “Mona Lisa” smile that is asymmetrically higher in the upper right
quadrant of this 29-year-old. Note the deep nasolabial folds.
Figure 14.74  Hyperkinetic lateral upper lip levators create a slight gummy canine
smile that is asymmetrically higher in the upper right quadrant of this 20-year-old.
Note the deep nasolabial folds.

Botulinum Toxins in Clinical Aesthetic Practice
230
The depressor septi nasi at times may require treatment with 1–2 U
of OnaBTX-A at the base or along the length of the columella when the
depressor action of the muscle is hyperkinetic. This additional maneu­
ver will help produce a more natural smile. By lowering the central
aspect of the upper lip, not only is the extent of an exaggerated gummy
smile reduced, but also the depth of a horizontal upper lip crease can
be diminished (see nasal tip ptosis above). However, if migration of
OnaBTX-A extends into the central superficial fibers of the orbicularis
oris, an inability to fully pucker the lips also will occur. An alternative
technique is to inject 1–2 U of OnaBTX-A intraorally into the bellies of
the two central upper lip levators. By passing the needle on either side
of the phrenulum through the gingivo-labial sulcus above the alveo­
lar ridge at the same point in the nasofacial groove and canine fossa
as described above (Figure 14.77).68 A minimum dose of low-volume
OnaBTX-A should just barely relax the central upper lip levators so
that the upper lip cannot fully retract upward. If the excessive gummy
show persists and is at its highest point in the center of the upper lip
with or without evidence of a transverse horizontal line across the
upper lip and philtrum, then an additional 1 U of OnaBTX-A can
be injected into the depressor septi nasi at the base of the columella
(Figures 14.33 and 14.78).
When treating a gummy smile with OnaBTX-A, most studies target
the LLS and the LLSAN as the main muscles to weaken and reduce
the height of a high lip line. In a study of 14 (13 female and 1 male)
Caucasian patients ages 23–48 years old by Suber and colleagues, the
Figure 14.75  Place the needle perpendicular to the skin surface and inject 1–2 U of
OnaBTX-A deeply into the belly of the muscle at the nasomaxillary groove while
the patient smiles excessively.
1
2
Figure 14.76  The central lip levators (i.e., direct retractors): levator labii superioris
alaeque nasi and levator labii superioris can be treated with 1 or 2 U of OnaBTX-A •
to diminish a gummy smile. The indirect retractor, depressor septi nasi, also may be
treated with 1–2 U of OnaBTX-A • when upper lip retraction is extreme. 1, levator
labii superioris alaeque nasi; 2, levator labii superioris.
Figure 14.77  The intraoral injection of the central lip levators may be less painful
to the patient, but a less precise way of injecting OnaBTX-A.
1
2
Figure 14.78  The central lip levators (i.e., direct retractors): levator labii superioris
alaeque nasi and levator labii superioris can be treated with 1 or 2 U of OnaBTX-A
• to diminish a gummy smile. The indirect retractor, depressor septi nasi, also may
be treated with 1–3 injection points along the columella with 1–2 U of OnaBTX-A
• when upper lip retraction elevation is extreme.

14.  cosmetic uses of botulinum toxin a in the mid face
231
topographical landmarks encompassing the preferred three injection
treatment points on the surface of the face corresponded to an inverted
triangle with one injection point 2 mm lateral to the alar-facial groove
at the level of the nasal passage, the other injection point 2 mm lateral
to the first point in the same horizontal plane, and a third injection
point 2 mm inferior and between the first two injection sites71 Figure
14.79b). This location adjacent to the ala nasi is the preferred site for
injecting OnaBTX-A and has been identified by many authors as the
area of intersecting muscle fibers of the LLS, LLSAN, and in some
individuals, the zigomaticus minor, when present.53,55,60,71,74–77
In a study of 50 hemi-faces of 25 (12 female and 13 male) Korean
cadavers between the ages of 47 and 88 years of age, Hwang and col­
leagues identified the ideal location lateral to the ala nasi for injecting
BoNT to treat a gummy smile.76 This ideal injection point is found at
the intersection of two lines, one approximately 1 cm–1.5 cm lateral
to the most lateral aspect of the ala nasi and the other approximately
3 cm up from the oral commissure (Figure 14.79a). They described
how the zygomaticus minor and the LLSAN were located in a super­
ficial plane that covered the medial and lateral margins of the LLS
and how all three muscles converged on a small triangular area lat­
eral to the ala nasi. They named the center of this triangle the “Yonsei
point.” This single injection point was located easily and felt to target
effectively the LLSAN, LLS, and zygomaticus minor with just a single
injection of OnaBTX-A, as opposed to Suber et al.71 and Polo60,77 who
injected each muscle separately. There was no statistically significant
difference in location measurements between males and females in the
Hwang study.76 Because the shape of the faces between Caucasians and
Asians may vary, an exact injection point for treating a gummy smile
may not be clinically obvious by ruler measurements; consequently,
the best way to identify the ideal injection point is to palpate the gen­
eral area lateral to the ala nasi and ask the patient to raise the upper lip
and make sneering motions as described above. When the contract­
ing muscle fibers can be palpated, then injecting OnaBTX-A into this
location is probably safe and effective, provided only 1–2 units of con­
centrated, low volume OnaBTX-A are injected.51,52,60,71,74–76
Mazucco
and
Hexsel
treated
with
abobotulinumtoxinA
(AboBTX-A) 16 patients with a maxillary gingival display of over
3 mm. They used a dose equivalency of 2.5:1 IU of AboBTX-A to
OnaBTX-A and injected subcutaneously. There were 3 patients with
an anterior gummy smile. They were injected at a standard location
1 cm lateral and 1 cm below the nasal ala to weaken the LLSAN. They
were injected with either 2.5 or 5 units of AboBTX-A depending on
the amount of gingiva exposed. There were 7 patients with a posterior
gummy smile and they were injected at two locations in the malar
region that followed a lateral and superior path corresponding to the
path of the zygomaticus major and zygomaticus minor. The first injec­
tion point was located in the nasolabial fold at the point of greatest
lateral pull during a full smile. The second injection point was 2 cm
lateral to the first point at the level of the tragus. At each injection
point, 2.5 units of AboBTX-A was injected.74 There were 3 patients who
had an anterior and posterior or “mixed” component to their gummy
smile. They were injected at all 6 points, 3 on each side of the midline,
in the locations just described; however, at the site closest to the nasal
ala, the dose was reduced by 50%, that is, only 2.5 units of AboBTX-A
were given, while the malar injections remained the same at 2.5 units.
There were 3 patients with asymmetric gummy smiles, who received
bilateral but asymmetric injections of AboBTX-A with a higher dose
on the hyperkinetic side according to the pattern of their asymme­
try. The contralateral side was also treated but with minimal doses of
AboBTX-A (2.5 units) at the more inferior location adjacent to the oral
commissure where the lateral pull was highest. The bilateral injections
were performed to avoid the possibility of reverse asymmetry caused
by compensatory muscle contraction of the untreated side.74
Outcomes (Results) (See Appendix 5) When Treating Excessive
Maxillary Gingival Display (Gummy Smile)
Treating patients with an exaggerated gingival smile can produce a
variety of anatomic and functional changes. By limiting the exagger­
ated upward movement of the upper lip with injections of OnaBTX-A,
an obvious reduction in the amount of upper gingival and dental show
will result, along with elongation of the upper lip, some flattening of
the philtrum, thinning of the vermillion, and effacement of the medial
aspect of the nasolabial fold and sulcus (Figure 14.51).
Patients who experienced the best results with the least amount of
adverse events were those individuals who primarily possessed a canine
or cuspid type smile and were successfully treated with 1 or 2 units of
concentrated, low volume OnaBTX-A.51,52 They usually are the ones
who gladly return for repeat maintenance treatments with OnaBTX-A
because their low dose, low volume treatments gave them the most nat­
ural appearing results with the least troublesome side effects.51,52
Even for those patients with a full type of gummy smile with ante­
rior and posterior components with or without asymmetry, minimal
doses of concentrated low volume OnaBTX-A is the best injection
technique. Start with low doses that can be augmented with another
1 or 2 units of OnaBTX-A after 2 or 3 weeks if necessary, when the
patient returns for a follow-up visit.
1 cm
3.0 cm
1.5 cm
A
B
3 cm
(a)
(b)
Figure 14.79  (a) Hwang and colleagues determined that the ideal injection point, the “Yonsei” point, is found at the intersection of two lines, one approximately 1 cm–1.5 cm
lateral to the most lateral aspect of the ala nasi and the other approximately 3 cm up from the oral commissure. (b) According to Suber et al., the preferred injection treat­
ment points on the surface of the face corresponded to an inverted triangle with one injection point 2 mm lateral to the alar-facial groove at the level of the nasal passage,
the other injection point 2 mm lateral to the first point in the same horizontal plane and a third injection point 2 mm inferior and between the first 2 injection sites. This
is almost identical to the “Yonsei” point.

Botulinum Toxins in Clinical Aesthetic Practice
232
Polo conducted a study to determine the doses required and the
injection sites preferred to correct gummy smiles, while providing
consistent, statistically significant and aesthetically pleasing results.60
Thirty patients (29 females, 1 male) with an upper gummy smile caused
by hyperfunctional upper lip levators received 2.5 U of OnaBTX-A at
two sites per side (a total of four sites) into two distinct points lateral
to the alar facial angle. The one injection point was more medial and
at the alar facial angle where the LLSAN overlaps the LLS. The other
injection point was more lateral and where the LLS overlaps the zygo­
maticus minor. The injection sites were determined only by palpation
of contracting musculature while the patient smiled. No electromyo­
graphic guidance was used like in his previous study.77 A gummy smile
was defined as an excessive gingival display above the tooth crown
of at least 3.0 mm on unrestricted, nonposed, “full-blown,” sponta­
neous smiling. The pretreatment gingival display averaged 5.2 mm
(±1.4 mm). Two weeks after treatment, the mean gingival display
declined to 0.09 mm (±1.06 mm). This was a mean reduction in gin­
gival display for all 30 patients of 5.1 mm. Along with the anticipated
relative lengthening of the upper lip on smiling, Polo also reported
a marked reduction of the nasolabial fold as the most frequently
observed accompanying side effect. Other attendant sequelae included
a reduction in the hypercontractibility of the transverse nasalis when
smiling and an effacement of lower periocular rhytides of the orbital
orbicularis oculi. This was thought to be caused in these particular
individuals by the attendant relaxation of the interdigitating muscle
fibers of their LLSAN, LLS, and zygomaticus minor which might have
been in close proxitmity to the transverse nasalis and muscle fibers of
the lower portion of the orbital orbicularis oculi. Polo believes a suc­
cessful treatment with OnaBTX-A depends on a multitude of factors,
including the physician injector’s appreciation of an individual’s par­
ticular facial aesthetics and the injector’s ability to discern correctly
which muscles are responsible for the particular movements causing
the wrinkles in question. There is a great deal of variability among
different individuals and the strength of their facial mimetic muscles
and how they move and produce wrinkling. However, injections of
OnaBTX-A are most successful when they are given into those mus­
cles that move in a perpendicular direction from the direction of the
wrinkles being treated. Polo also concluded that the dose of 5 U per
side was best for patients who had at least a 5.0 mm gingival display.
For those who had less than a 5.0 mm gingival display, lower doses of
OnaBTX-A were more appropriate. The results lasted 24–30 weeks.60
In addition, it may be possible to diminish the appearance of an
idiosyncratic horizontal rhytide when it is present across the upper
lip (Figure 14.80). An additional 1–2 U of OnaBTX-A at the base of
the columella into the depressor septi nasi by the technique described
above may be necessary to further diminish the depth of the central
aspect of this horizontal upper lip rhytide (Figure 14.35). Most of the
time, however, injections of a soft tissue filler are the only reliable way to
completely efface a deep, transverse upper lip wrinkle, especially when
it persists after an OnaBTX-A treatment of the central levators of the
upper lip (see Figure 14.41). Most patients who develop the transverse
rhytide across their upper lip seem to be those over the age of 60 who are
of light complexion (usually of skin type II and III), have spent a lot of
time outdoors, and may or may not have a history of smoking tobacco
(Figures 14.62 and 14.80).
Suber et al. treated with OnaBTX-A 14 patients (13 females and 1
male) who only possessed a cuspid type (canine) smile with a 2 mm
or more gingival display.71 Between 4 and 6 units of OnaBTX-A were
injected at three sites on both sides of the nose lateral to the alae nasi
and into the LLS and LLSAN. Before the injections of OnaBTX-A
the gingival show over the central incisors averaged 4.89 mm
(range, 3–7 mm) and 4.25 mm (range, 1–7 mm) above the canines.
Approximately 2 weeks after the OnaBTX-A injections, the gingival
show decreased on an average of 4.14 mm (range, 1–8 mm) over the
central incisors and 3.51 mm (range, 1–5 mm) above the canines. No
major complications were observed.71
All patients in the Mazzucco and Hexsel series experienced a
decrease in their exaggerated gingival display of over 75%.74 The average
improvement of patients with an anterior gummy smile was 96%; with a
posterior gummy smile, 61.06%; with a mixed gummy smile, 90.1%; and
with asymmetry, 71.93%. Adverse effects were mild and minimal. One
patient with a posterior gummy smile developed asymmetry after the
initial treatment, and was corrected with 2.5 units of AboBTX-A into
the nasolabial fold on the side of greater gingival exposure at a follow-
up visit. Another patient with a posterior gummy smile had difficulty
with smiling. The physical examination revealed a slight lowering of the
commissures creating a “sad smile,” which was attributed to hyperactiv­
ity of the depressor anguli oris on both sides of the mouth. This was suc­
cessfully treated with 5 units of AboBTX-A bilaterally into the depressor
anguli oris. None of the patients in this study reported any difficulty
with any lip movement or with speaking.74
Treating exaggerated maxillary gingival exposure with BoNTs pro­
vides affected patients with a quick and affordable solution that is safer
and less traumatic than any surgical procedure currently available.
Results can last anywhere from 3 to 6 months and sometimes even
longer when treatments are executed properly.
(a)
(b)
Figure 14.80  Note the transverse rhytide across the upper lip in this light complexioned 68-year-old individual both at rest and when smiling.

14.  cosmetic uses of botulinum toxin a in the mid face
233
Complications (Adverse Sequelae) (See Appendix 6) When
Treating Excessive Maxillary Gingival Display (Gummy Smile)
Because of the anatomy of the different codependent levator muscles
and their attachments in both the upper lip skin and orbicularis oris,
the risk–benefit ratio of treating a patient with a gingival smile is high
and the potential comorbidity is significant. When attempting to treat
an exaggerated maxillary gummy smile with injections of OnaBTX-A,
assistance with an electromyograph (EMG) might ensure more accu­
rate needle placement and avoid untoward results.77 The upper lip
levators (i.e., levator labii superioris alaeque, levator labii superioris,
the zygomaticus complex, risorius, levator anguli oris, and orbicu­
laris oris) (Figure 14.81) can easily be affected by the least amount of
inadvertent diffusion of OnaBTX-A. Inaccurate needle placement or
overzealous dosing in this area is subject to upper lip ptosis, buccal
sphincter incompetence, and an asymmetric smile. This in turn leads
to an inability of the upper lip to appose the lower lip completely and
tightly or to move in a full smile or pucker. This can lead to dysarthria,
and difficulty with producing particular sounds and articulating cer­
tain words. Buccal sphincter incompetence can result in an embar­
rassing public display of functional compromise, especially when
incontinence of liquid or solids is an unexpected and unavoidable
consequence.
Patients with a Mona Lisa or commissural smile after being treated
with OnaBTX-A for a high lip line found themselves with a “joker-
like” smile, because the central lip levators were weakened while the
lateral lip levators were not.51,71 This allowed the commissures of the
mouth to move higher laterally and the center of the lip to remain low
without elevation (Figure 14.69b).
Patients with a full denture or complete smile have a reverse type
of result to those with a Mona Lisa or commissural smile. Because a
full denture smile recruits both the upper lip levators and lower lip
depressors when a smile is activated, it can create a range of differ­
ent anterior and posterior gummy smile profiles, depending on the
variable strength of the muscles producing it. When either the center
of the upper lip or the zygomatic component of the posterior maxil­
lary gingival overexposure are treated with OnaBTX-A to reduce the
maxillary gingival display, the normally functioning unopposed lower
lip lateral depressor, that is, the depressor anguli oris will pull down
vigorously on the lateral commissures. With the upper lip central and
especially lateral levators weakened and the lower lip depressors con­
tracting in full compensatory activity, a grimace is produced or even a
look of dismay or horror when a smile is attempted. This was identified
as a “sad smile” when a posterior type of gummy smile was treated by
Mazzuco and Hexsel.74 They remarked that if the depressor anguli oris
is observed as hyperactive prior to treating a gummy smile, then it
should be treated at the same time along with the other muscles which
are being treated for a gummy smile.
When reviewing the present literature on treating gummy smiles
it is important to keep in mind that all the studies used fixed doses to
weaken the upper lip retractors no matter how strong or weak they were
or how high the maxillary gingival reveal was. However, the patients
with the stronger muscles and the highest gingival exposure did better
than those with weaker muscles and lesser gingival displays because the
dose was not reduced to accommodate their weaker muscles. In clini­
cal practice, on the other hand, it is of paramount importance to tailor
the dose of BoNT in proportion to the strength of the muscles being
treated, especially in the midface. Because the deep and superficial
mimetic muscles of the midface are contiguous and even interdigitate
with each other, any amount of BoNT injected in any area no matter
how directly localized to a muscle the injection is given, the toxin will
easily and freely spread into the adjacent muscles that might have simi­
lar or not so similar actions. In the mid face, one only needs to weaken a
muscle lightly with minimal amounts of OnaBTX-A to get a significant
response, unlike treating the upper face where large doses of OnaBTX-A
are necessary to realize the expected outcome. Consequently, because of
diffusion characteristics, ease of dosing, and outcome reliability, many
physician injectors will prefer OnaBTX-A over AboBTX-A when treat­
ing patients in the mid and lower face.76 Because of their overall small
size and reduced strength, as is indicative of most mid face muscles,
their response to treatment with OnaBTX-A can still be precariously
variable in the mid and lower face than it is with the larger muscles of
the upper face. Mid and lower facial muscles frequently respond differ­
ently to the first and subsequent injections of OnaBTX-A. With each
subsequent injection, the muscles remain weakened for a longer period
of time and require less dosing, probably because of disuse atrophy.
Other reported adverse events after OnaBTX-A injections for a gummy
smile are usually due to either inexperienced injectors’ overzealous or
misplaced injections or both, causing ptosis or elongation of the upper
lip; grossly asymmetric, “funny-looking” and dysfunctional smiles;
as well as difficulty with chewing and attendant severe drooling; an
inability to pucker the lips or enunciate certain words or sounds, and
“stroke-like” animation.1,78 In a response to Niamatu, Polo confirms the
importance of understanding the functional anatomy of all the mimetic
muscles of the face, and knowing exactly where the limits of the muscles
are before injecting them, being conservative in treating the mid face
musculature with low doses of concentrated OnaBTX-A and keeping
meticulous clinical and photographic records so that repeat treatments
are reproducible with the same outcomes.79
Treatment Implications When Injecting a Gummy Smile

1. Injecting OnaBTX-A into the central upper lip retractors (leva­
tor labii superioris alaeque nasi, the levator labii superioris,
and zygomaticus minor) at a particular point lateral to the alae
nasi can reduce an exaggerated gingival show by elongating the
upper lip.

2. Inject the central upper lip retractors only when they definitely
can be palpated as they contract lateral to the alae nasi; oth­
erwise, adjacent, nontargeted muscles will be affected, and lip
competence and symmetry will be compromised.
1
2
3
4
5
6
7
Figure 14.81  Properly functioning levator labii superioris alaeque nasi, zygomat­
icus major and minor, levator labii superioris, levator anguli oris, risorius, and
orbicularis oris are essential for buccal sphincter competence. 1, levator labii supe­
rioris alaeque nasi; 2, levator labii superioris; 3, levator anguli oris; 4, zygomaticus
minor; 5, zygomaticus major; 6, orbicularis oris; 7, risorius.

Botulinum Toxins in Clinical Aesthetic Practice
234

3. Patients with a canine smile are the best candidates to receive
OnaBTX-A injections for an exaggerated maxillary gingival
smile.

4. Injecting OnaBTX-A into the levator labii superioris alaeque
nasi also will efface the upper medial aspect of the nasolabial
sulcus and fold and flatten the philtrum and attenuate the
vermillion.

5. Inject only low volumes of low doses of concentrated OnaBTX-A
in the perinasal area. The depressor septi nasi also may need to
be injected with OnaBTX-A to diminish the depth of the trans­
verse horizontal furrow in the center of the upper lip if it persists
after injections for a gummy smile. Complete effacement is usu­
ally only accomplished with injections of a soft tissue filler.

6. Treat with injections of OnaBTX-A a hyperactive depressor
anguli oris along with the upper lip levators when reducing an
exaggerated posterior maxillary gingival display of someone
with a canine, or a complete full-denture type smile otherwise,
a sad smile grimace will result.

7. Photographic to any treatment with OnaBTX-A, inform the
patient of the potential risks, benefits, comorbidities, and inher­
ent functional and cosmetic changes expected when perioral
mimetic muscles are weakened.
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236
Cosmetic uses of botulinum toxin A in the lower face, neck, and upper chest
Anthony V. Benedetto
INTRODUCTION
Anatomic delineation of the lower face for our purposes encompasses
the perioral region, chin, and jaw line, which is the area that includes
the remainder of the superficial muscles of facial expression. One
of those muscles is the sheet-like neck muscle, the platysma. Even
though it originates in the mid to upper chest, most of its insertions
are in the lower and mid face. The platysma functions as one of the
essential mimetic muscles of the lower face, and therefore is included
in this chapter.
It is advisable to remind patients prior to any treatment, that inject­
ing onabotulinumtoxinA (OnaBTX-A) for cosmetic purposes in the
lower face or anywhere else on the face or body except in the fore­
head, glabella and lateral canthi is done off-label and without FDA
approval.
The orbicularis oris, the major peribuccal muscle, functions as a
sphincter providing a combination of circular as well as levator and
depressor movements to the upper and lower lips, including the cor­
ners of the mouth. The other supplementary perioral muscles consist
mostly of separate individual levators of the upper lip and depres­
sors of the lower lip. These perioral levator and depressor muscles
do not always move antagonistically to each other, especially when
they contract involuntarily, but often function synergistically with
one another in a spontaneous manner. This is in direct contrast with
the upper face where levators and depressors function in a more
antagonistic fashion, and move in direct opposition to each other.
The perioral muscles open and close the mouth and perform essential
buccal functions in unison with the orbicularis oris, such as main­
taining the sphincter control and lip competence that is necessary
when the mouth is filled with solid material, liquid, or air. Additional
vital functions of the orbicularis oris acting as an agonistic muscle
together with its ancillary levators and depressors include the ability
to make sounds and articulate them into speech, or chew and swal­
low solids and liquids. In addition, by contracting the orbicularis oris
along with its levators and depressors in a particularly subtle and
idiosyncratic manner, a person can express various emotions sponta­
neously, either deliberately or involuntarily.
Muscle fibers of the orbicularis oris interdigitate with most, if not
all, of the upper lip levators and the lower lip depressors. Although
there is a certain interdependence with all the perioral muscles, the
orbicularis oris also can function independently as an antagonistic
muscle and deliberately oppose the actions of the labial levators and
the depressors. For example, one can move the orbicularis oris and
the lips intentionally to open or shut the mouth as one does when
eating or drinking, and to purse or pucker the lips as one does when
sucking or blowing air, liquid or solids in or out of the mouth. In
addition, the lips function as the sentinels of sensation, monitoring
temperature, and moisture content and consistency of the solid or
liquid that is about to enter or exit the mouth.1
These subtle but functional differences in the way the various peri­
oral muscles operate play a significant role in how to devise a treat­
ment plan with OnaBTX-A. One cannot just identify a levator or
depressor in the lower face and weaken it as one does in the upper face
with injections of OnaBTX-A without affecting adjacent muscle fibers
of differently functioning muscles and possibly producing adverse
sequelae. Some of these untoward effects can include lip asymmetry;
sphincter incompetence affecting mastication or deglutition; a distur­
bance in sound production and word pronunciation, and the inability
to accurately convey nonverbal communication and emotions in
a deliberate or in a spontaneous, involuntary manner. However, as
our injection techniques improve and our understanding of how the
muscles in the lower one-third of the face respond to OnaBTX-A, it
is becoming increasingly obvious that the lower face and neck should
be treated in unison as a defined all-encompassing cosmetic unit. The
approach to treating the lower one-third of the face should be similar
to that of the upper one-third of the face, that is, to treat the area
all-inclusively as a functional unit and not as separate, independent
muscles. In the upper face, there is one large levator, the frontalis, that
interdigitates with and opposes the four depressors of the brow and
periorbital area. In the lower face, there is the one large depressor,
the platysma that interdigitates with the levators and depressors of
the lower face and perioral area. The platysma can either intention­
ally oppose or subtly and spontaneously supplement the movements
of these lower face muscles. Therefore, because of these functional
differences and complex muscle interactions in the lower face, only
the very experienced physician should attempt to reduce the various
rhytides of the lower face or correct anatomic variations and asym­
metries of this area with injections of OnaBTX-A. Otherwise, what
was intended to be remedied might be exacerbated.
PERIORAL LIP LINES AND RHYTIDES
Introduction: Problem Assessment and Patient Selection
Just as the eyes are the center of focus for the upper face, enabling an
individual to express deep felt emotions and personal sentiment, the
mouth also is the center of focus for the lower face, enabling one to
express oneself with varying degrees of attitude and emotional spon­
taneity. Full and rounded lips with a smooth and distinct projected
border of the vermilion, delineating it from the rest of the cutaneous
lip, is the hallmark of youth with all its pristine beauty. With time and
sun exposure, the lips become thin, flaccid, elongated, and wrinkled,
lacking substance, contour, and projection. What once reflected a
person’s vitality and sensuality now reveals the passing years of trials
and tribulation, leaving one appearing weary and worn, evidenced by
a wrinkled face with thin lips and perioral rhytides.
Both static and dynamic wrinkling can be found around the
mouth appearing as vertical lip lines perpendicular to the vermilion
border. It has been shown that static perioral wrinkles are caused not
only by intrinsic aging and photodamage, but also are precipitated
and enhanced by the smoking of tobacco.2 Frequent and chronic ciga­
rette smoking also can augment perioral dynamic wrinkles, probably
because of the persistent lip puckering and pursing needed to hold a
cigarette in the mouth while inhaling and exhaling tobacco smoke,
hence the epithet “smoker’s lines” (Figure 15.1a, b). Dynamic perioral
wrinkles are found in those who are genetically predisposed and fre­
quently pout and repetitively purse their lips, whether deliberately or
involuntarily. This is seen more commonly in women in the way they
habitually move (i.e., pucker or purse) their lips during routine daily
activities of eating, drinking, and speaking (Figure 15.2a). Activities,
such as cigarette smoking, sipping liquids from a straw, whistling,
and playing certain musical wind instruments, provide a supplemen­
tal cause in the formation of dynamic perioral rhytides. Repeated
purse-string-like movements of the orbicularis oris exaggerate and
intensify the dynamic perioral lines daily. Men usually are not in the
habit of pursing or puckering their lips as women (Figures 15.1a and
15.2b). Some believe that because men also are “blessed” with facial
15

15.  cosmetic uses of botulinum toxin a in the lower face, neck, and upper chest
237
and perioral beard hair, they unlike women, are spared from the fine
infolding and wrinkling of facial and labial skin. However, Paes et al.
performed a comparative study of the lips of fresh cadavers of both
men and women. They meticulously performed full thickness ana­
tomical dissections of the lips and then made histologic glass slide
preparations of full thickness sagittal sections of the same lips and
examined them microscopically. They then compared in a blinded
fashion the lips of both women and men looking for gender specific
differences in perioral skin. They found that women had significantly
more and deeper perioral wrinkles than men possibly because of other
more important reasons than just because of the lack of a beard.3 The
histologic examination of the full-thickness specimens of the perioral
skin of men displayed a considerably higher number of sebaceous and
sweat glands as well as a higher ratio of blood vessels to connective tis­
sue in the labial dermis than that of women. Amazingly, the amount
of hair follicles did not significantly differ between men and women,
although the average number of sebaceous glands per hair follicle was
greater in men. They concluded that because women’s labial skin con­
tains a significantly smaller number of appendages than men, women
might be more susceptible to the development of perioral wrinkles.
Incidently, Paes et al. also found the orbicularis oris, which surrounds
the lips, is anchored 1.5 times closer to the dermis in women than in
men. This could conceivabley cause a stronger inward traction and
pull on the skin of women’s lips as they speak, eat, drink, and express
themselves, thereby creating deeper perioral wrinkles on a constant
and routine basis.3 Although men are less afflicted than women with
perioral wrinkling, they are not specifically bothered by them when
and if they do occur. However, women are particularly frustrated by
“lipstick bleeding,” especially when lipstick channels up and down
these rhytides blurring the outline of the vermilion (Figure 15.3).
There are many other causes for these perioral vertical lines
besides repetitive puckering of the orbicularis oris. When they are
produced by chronological aging and environmental exposure,
these types of wrinkles are more static in nature. Static wrinkles can
result from either identifiable causes, like aging and sun exposure,
or unknown causes like genetics, gender differences, intrinsic soft
tissue characteristics, and anatomic idiosyncrasies like the shape
of the mouth and how it moves while functioning on a daily basis.
Much of the static wrinkling of the perioral area can be reduced by
invasive surgical procedures such as ablative skin resurfacing, (e.g.,
fractionated or nonfractionated laser resurfacing, mechanical derm­
abrasion, or chemical peeling) and possibly by other different types
(a)
(b)
Figure 15.1  (a) Note the perioral wrinkles that are produced when this 56-year-old inhales on a cigarette. (b) Same patient puckering 1 month after treatment with OnaBTX-A.
Note the absence of the intense perioral wrinkles in this smoker, and the fullness and eversion of the upper and lower vermilion (pars marginalis) after treatment.
(a)
(b)
Figure 15.2  (a) Note the perioral wrinkles in this 57-year-old woman expressing her displeasure and exasperation by pursing her lips. She refused perioral OnaBTX-A
treatments because she sang in a professional choir. (b) Note the lack of perioral wrinkles produced when this 77-year-old inhales on a cigarette.

Botulinum Toxins in Clinical Aesthetic Practice
238
of interventional surgical procedures, like rhytidectomy, subcision,
excisions, implants and injections of synthetic soft tissue fillers or
autologous fat.
It is extremely important to distinguish the dynamic wrinkles of
the lips from those that are static. Static wrinkles usually are not sub­
stantially affected by injections of BoNTs. Static wrinkles can be eas­
ily distinguished from dynamic wrinkles by asking a person to purse
their lips. If there are rhytides present in the lips prior to pursing
them and there is minimal change or intensification of these wrinkles
with movement, then their perioral rhytides are primarily static and
generally not reducible by OnaBTX-A (Figure 15.4). Static wrinkles
are more commonly found in someone over the age of 60–65 years
or in a younger person who has acquired extensive solar elastosis of
their exposed skin. If, on the other hand, the wrinkles accentuate and
deepen with lip movement and puckering no matter how young or
old a person is, then these are dynamic wrinkles and can be dimin­
ished with injections of OnaBTX-A (Figures 15.5a–d and 15.6a–d).
Functional Anatomy of Perioral Lip Lines and Rhytides
(see Appendix 1)
The upper lip extends from the base of the nose to as far lateral as the
nasolabial folds down to the free edge of the vermilion. The lower lip
extends from the free edge of the vermilion down to the labiomental
sulcus. The shape of the mouth and the position of the lips are con­
trolled by a complex three-dimensional arrangement of interlacing
and decussating bundles of different mimetic muscles.1 In the upper
lip these include various levators, retractors, and evertors (i.e., leva­
tor labii superioris alaeque nasi, levator labii superioris, zygomaticus
major and zygomaticus minor, levator anguli oris, and risorius). In the
lower lip they include various depressors, retractors, and evertors (i.e.,
depressor labii inferioris, depressor anguli oris, mentalis, and pla­
tysma). Both the upper and the lower lips are interlaced with muscle
fibers of the multilamellar, compound sphincter, the orbicularis oris,
and those of the accessory muscle of mastication, the buccinator.4
The function of the orbicularis oris is to close the mouth by approxi­
mating the lips if and when they are opened by the buccal levators and
depressors. By contracting the deep fibers and the superficial oblique
ones, the orbicularis oris can apply the lips closely to the alveolar
arches. The superficial interdigitating muscle fibers of the orbicularis
oris, on the other hand, shape the lips in different configurations and
either bring the lips together against the teeth or protrude the lips and
the corners of the mouth forward to produce the maneuvers of pursing
or puckering the lips for certain functions such as whistling or kiss­
ing. Because of its mouth-closing function, the orbicularis oris can be
considered, in part, an antagonist to the lip levators and depressors.
The orbicularis oris was once assumed to be a series of complete
ellipses of striated muscle that acted in unison as a sphincter around
the oral cavity. However, the orbicularis oris is not just a simple
sphincter like the orbicularis oculi. Instead the orbicularis oris is
comprised of multiple lamellae of deep and superficial muscle fibers
traversing in different directions around the orifice of the mouth
that originate and emanate from the modiolus just lateral to the oral
commissures.1,5 The orbicularis oris is now understood to consist of
four independent quadrants (right, left, upper, and lower) of striated
muscle, each quadrant containing a larger pars peripheralis and a
smaller pars marginalis (i.e., eight segments in total). These four right
and four left anatomic parts (upper and lower right and left partes
peripherals and upper and lower right and left partes marginales)
are juxtaposed to each other, respectively, and roughly correspond
to the exterior anatomic delineations of the free or unattached por­
tion of the lips (Figure 15.7a). The smaller, but thicker pars marginalis
corresponds to the vermilion of the lip and the larger, but thinner
pars peripheralis corresponds to the remainder of the free unattached
portion of the cutaneous lip. Consequently, the orbicularis oris is
perceived as being composed of eight segments, each resembling a
Figure 15.3  Blunting of the vermilion border in this 74-year-old is offset by lip­
stick. Note lines of lipstick tracking up and down the perioral rhytides.
(a)
(b)
Figure 15.4  (a) A 72-year-old patient with deep perioral rhytides and moderate solar elastosis of the face and lips at rest. Her perioral rhytides barely intensified with puck­
ering. (b) Note the persistence of the perioral rhytides 1 month after a treatment of OnaBTX-A injections, because the bulk of her wrinkles were age-related and static in
nature. Note also the eversion and fullness of the upper lip at rest after treatment.

15.  cosmetic uses of botulinum toxin a in the lower face, neck, and upper chest
239
fan, whose apex begins at the modiolus, consisting of superficial and
deep slips of muscle, one set on top of the other in different planes
(Figure 15.7c).
The upper and lower lip muscle fibers of the pars marginalis are
arcuate in form extending from the two corners of the mouth and
blending with each other as they encircle the oral cavity parallel to
the shape of the vermilion of the lip (Figure 15.7c). Pars margina­
lis forms a continuous band of muscle fibers across the lip, curling
upward at the anterior aspect of the muscle, in the shape of a hook,
forming the white roll seen along the interface between the pars mar­
ginalis and the pars peripheralis6,7 (Figure 15.8c,d). This interface of
the two muscle segments, also known as the vermilion border, is the
only place where the pars marginalis and pars peripheralis meet and
attach to the undersurface of the dermis. Since the muscle fibers of
the pars marginalis of the orbicularis oris are thicker and bulkier,
and occupy a more anterior frontal location of the lips than the pars
peripheralis, they are responsible for the curled outward and upward
curved “hook”-like projection and shape of the lip vermilion. This
overall outline of a hook or curl of the lip has also been described by
different authors as a “J” or hockey stick shape on sagittal section­
ing of the lips, which becomes more pronounced as one contracts
the lips when closing the mouth8 (Figure 15.8b). In some individu­
las depending on their race and ethnicity this marginal “hook” is
more marked in rounded and fuller lips, and less well defined in flat­
ter, thin lips. It is also greater in length in the lower lip than in the
upper lip8 (Figure 15.8b). The pars marginalis of the orbicularis oris
functions more like a sphincter, opening and closing the mouth and
lips.5 The pars peripheralis has more of a dilatory function, widening
and stretching the mouth and protruding the lips as one frequently
must do at the dentist.1,5 As the muscle fibers of the orbicularis oris
enter their respective superior and inferior labial tissue, they aggre­
gate into cylindrical bundles of muscle fascicles oriented parallel to
the vermilion. The muscle fibers of the direct labial retractors procede
to their areas of submucosal attachment in the pars peripheralis and
pars marginalis by passing in between and beneath these cylindrical
bundles of orbicularis oris.4
In the upper lip pars peripheralis, muscle fibers of the orbicularis
oris insert into the incisive fossa of the maxilla, the nasolabial sulcus,
the nasal ala, nasal spine, and caudal septum. In the lower lip pars
peripheralis, fibers of the orbicularis oris insert onto the mandible
at the mentolabial sulcus. Minor fascicles of the orbicularis oris also
terminate in the connective tissue of the lips, into the dermis and sub­
mucosa as they traverse through all the quadrants of the free lips.4
In the upper lip, most muscle fibers of the orbicularis oris continue
toward the midline, crossing over it at least 5 mm into the opposite
side of the lip (Figure 15.7c). Consequently, these interlacing and
crisscrossing muscle fibers just lateral to the midline in the center of
the upper lip play a significant role in forming the lateral ridges of
the philtrum as they insert into the dermis. The central depression or
concavity called the philtrum is flanked on either side by these phil­
tral ridges or escarpments, also called philtral columns. They begin
at the base of the nose and continue down the upper lip and end at
(a)
(b)
(c)
(d)
Figure 15.5  (a) A 53-year-old with deep perioral rhytides and severe solar elastosis of the face and lips is shown at rest and (b) with puckering before a treatment with
­OnaBTX-A. Note the rhytides intensify with puckering. (c) Same patient at rest and (d) puckering 3 weeks after her first treatment with OnaBTX-A. Note the rhytides at
this early post-treatment time have only partially effaced. Note also the fullness and eversion of the vermilion after OnaBTX-A.

Botulinum Toxins in Clinical Aesthetic Practice
240
the highest peaks of the vermilion border. The philtral depression, on
the other hand, continues more inferiorly into the depth of the “V”
shaped indentation in the center of the upper lip. The overall outline
of the vermilion in the center of the upper lip is likened to Cupid’s
bow. The philtral depression is attributed to a sparseness of soft tis­
sue and a lack of dermal insertions of decussating muscle fibers. It
functions as a reservoir of extra distensible skin, facilitating a person’s
ability to open the mouth as wide as possible. The overall pattern of
the philtrum can vary, depending on the overall size and shape of the
face6,9–11 (Figures 15.7c and 15.8e, f). Similarly, in the lower lip these
crisscrossing muscle fibers interlace with their contralateral slips of
muscle just a few millimeters beyond the midline and then attach to
the dermis within and below the vermilion zone. This helps form the
mental crease, an inverted “U” shaped depression, also known as the
mentolabial sulcus.4 This external lower border of the lower lip also
corresponds to the inferior margin of the gingivolabial sulcus inside
the mouth.1 Similar muscle crisscrossing and overlap beyond the mid­
line of the lip vermilion also occurs in the pars marginalis. It is the
dense capillary network within the pars marginalis that gives it its ver­
milion color. The pars marginalis of the orbicularis oris is unique to
humans and only found in the lips of hominids. Lips are crucial in the
production of sound and necessary for the enunciation of speech.12
Direct labial retractors are those levators and depressors that
enter directly into the tissue of the lips without passing through and
interlacing with the muscles of the modiolus (Figure 15.7b). For the
most part, when these muscles contract, they exert a vertical pull at
right angles on the buccal aperture. That is, they either elevate or
evert in part or entirely the upper lip and they depress or evert in
part or entirely the lower lip (Figure 15.8a). The position of the direct
upper lip retractors is from medial to lateral: the lateral labial portion
of the levator labii superioris alaeque nasi, levator labii superioris,
and zygomaticus minor. In the lower lip, they are the depressor labii
inferioris and platysma, pars labialis (Figure 15.8a). The pars labialis
of the platysma is located in the same plane as the depressor anguli
oris and depressor labii inferioris, and interdigitates its fibers with
theirs, occupying any vacant space between them (Figure 15.9). In
both the upper and lower lips, the direct labial retractors interlace
their fibers into a continuous sheet of muscle superficial and deep to
the intrinsic fibers of the pars peripheralis and pars marginalis of the
orbicularis oris as they travel through the substance of the free lip
and sequentially attach to the undersurface of the dermis and mucous
membrane. The orbicularis oris interdigitates superficially and deeply
with all the direct retractors as well as with the modiolar muscles of
both the upper and lower lips. Movements of the direct retractors can
be modified deliberately or spontaneoulsy by the superseding activity
of the modiolar muscles and the orbicularis oris to produce the fine
and delicate labial movements required to whistle, enunciate different
sounds, express certain emotions, and communicate nonverbally.4
(a)
(b)
(c)
(d)
Figure 15.6  (a) A 66-year-old with deep perioral rhytides and moderate solar elastosis of the face and lips at rest and (b) puckering before a treatment with OnaBTX-A. Note
that rhytides intensify with puckering. (c) Same patient at rest and (d) puckering 2 weeks after a treatment with OnaBTX-A. Note the fullness of the vermilion at rest and
with puckering, and the reduction of rhytides with puckering.

15.  cosmetic uses of botulinum toxin a in the lower face, neck, and upper chest
241
The modiolus (Latin for hub) is a small button-shaped nodule
approximately 2 cm just lateral to the oral commissures (cheilion)
where the orbicularis oris and indirect labial retractors converge
toward this centralized anatomic location. Their muscle fibers decus­
sate with each other and then diverge from it, while forming a dense,
compact, but mobile, fibromuscular and tendinous mass of connec­
tive tissue13 (Figure 15.7). A well-developed modiolus can be palpated
and often appears as a dimple when contracted.14 It renders the lower
face tonic, functioning as the main aesthetic landmark and natural
aesthetic unit of the inferior third of the face.15 The modiolus also is
intimately connected with the nasolabial fold because the orbicularis
oris and some of the levator muscles of the upper lip pass through
the modiolus to participate in the formation of the nasolabial fold
directly or indirectly.16 A long convex nasolabial fold appears in
individuals with a weak trophic modiolus, whereas a short concave
nasolabial fold appears in persons with a large trophic modiolus.13
In addition, the superficial fascia (superficial musculoaponeurotic
system or SMAS) of the face at times can continue medial to the
(a)
(b)
(c)
1A
1B
2A
2B
3A
3B
4A
4B
1
2
3
4
5
6
7
8
9
10
3
1
2
Figure 15.7  (a) The four quadrants (marked by dashed lines) and eight segments (black dots) of the orbicularis oris: 1A, pars peripheralis superioris, 1B, pars marginalis
superioris; 2A, pars marginalis inferioris, 2B, pars peripheralis inferioris; 3A, pars peripheralis superioris, 3B, pars marginalis superioris; 4A, pars marginalis inferioris,
4B, pars peripheralis inferioris. (b) The modiolus is a small kidney-shaped nodule approximately 2 cm just lateral to the oral commissures (cheilion) where the orbicularis
oris and indirect labial retractors converge and decussate with each other and then diverge, forming a dense, compact, but mobile, fibromuscular and tendinous mass of
connective tissue. 1, orbicularis oris; 2, zygomaticus major; 3, levator anguli oris; 4, buccinator; 5, risorius; 6, depressor labii inferioris; 7, depressor anguli oris; 8, platysma
(pars mandibularis); 9, mentalis; 10, modiolus. (c) In the upper lip, most muscle fibers of the orbicularis oris continue toward the midline, crossing over it at least 5 mm into
the opposite side of the lip. 1, philtral columns; 2, orbicularis oris, pars peripheralis; 3, orbicularis oris, pars marginalis and vermilion.