Phẫu Thuật Tạo Hình Thẩm Mỹ Khuôn Mặt Người Á Đông

III Blepharoplasty
234
placement of well-organized septum and orbital fat between
the orbicularis oculi and the levator aponeurosis. The post-
orbicularis fascia and muscle are lowered from the previous
site of adhesion and anchored to the tarsal plate (Fig. 18.22).
ume (subcutaneous or deep fat) in the upper eyelid above
a naturally existing supratarsal fold. This presentation is
within the spectrum of sunken eyelids and develops over a
relatively long time period. Most often, primary triple folds
are presenting symptoms in elderly patients and in patients
who have lost signi cant body weight.
Secondary triple folds are present in patients after the
index blepharoplasty. Overzealous soft tissue removal in
the upper ap can create adhesion and subsequently result
in an extra eyelid crease above the surgically created fold.
In particular, removal of the medial retro-orbicularis oculi
fat (ROOF) may lead to triple fold and should be avoided. At
times, pretarsal or pre-aponeurotic soft tissue is removed
to facilitate adhesion and formation of the eyelid crease.
However, removal of this tissue above the point of xation
should be avoided because it may result in triple fold for-
mation (Fig. 18.18 and Fig. 18.19).
Tertiary triple folds form after secondary operations for
correction of high fold, ectropion, or eyelid retraction. The
extra creases are all consequences of re-adhesion from pre-
vious operations (Fig. 18.20 and Fig. 18.21).
If the extraneous crease is shallow, fat injection alone
might be enough to bolster the skin and prevent further
progression of the crease. Minor adhesions can be released
using an 18-gauge needle subcision, but this does not
allow for interposition aps. In most cases, open access is
required for meticulous release of adhesions and to per-
form preventive measures.
The upper ap should be released between the levator
aponeurosis and orbital septum. Usually, this division alone
is su cient in releasing the adhesion forming the extrane-
ous crease. If this is not the case, however, the space between
the postorbicularis fascia and the orbital septum should be
cleared for additional separation of outer and inner elements.
The later plane of dissection should be more extensive and
extend superiorly. Re-adhesion is prevented by inferior dis-
a
b
c
Fig. 18.17 The height of extra folds corresponds to the underly-
ing cause. (a) De ciency or excess removal of orbital fat. (b) Excess
removal of connective tissue and/or ROOF. (c) Excess removal of
orbicularis oculi muscle.
Fig. 18.18 Triple fold from excision of connective tissue. Removal
of the oculi muscle in the upper ap (upper arrow) can result in
triple fold. This is especially true when the oculi muscle excision is
further away from the xation point (bottom arrow, loop).
Area of fixation
Area of soft
tissue removal
Area of fixation
Area of soft
tissue removal
A line in high risk of
triple fold formation
Fig. 18.19 Soft tissue removal and area of xation. (a) Fixation
should be done at the highest point of soft tissue removal. (b) If
xation is done lower than the area of soft tissue removal, a triple
fold can be formed at the area of soft tissue removal.
a
b

18 Management of Double-Eyelid Surgery Complications
235
Previous
fixation level
New fixation level
Fig. 18.20 In case high xation is lowered, a triple fold can
develop because a double fold can easily develop at the area of the
previous xation site.
Fig. 18.21 Triple fold formation by absence of xation point. (a)
Point of xation (x) descends after blepharoptosis correction, which
has the e ect of correcting and preventing triple fold. (b) On the
other hand, and by the same principles, the absence of a xation
point by levator muscle recession during the correction of retracted
eyelid can result in triple fold.
Fig. 18.22 Correction or prevention of triple fold. (a) If the release of the upper ap between the levator aponeurosis and the orbital
septum is not su cient to correct the triple fold, the space between the postorbicularis fascia and the orbital septum should be dissected
extensively and superiorly for additional separation of outer and inner elements. (b) Re-adhesion can be prevented by inferior displace-
ment of well-organized septum and orbital fat between the orbicularis oculi and the levator aponeurosis. (c) The postorbicularis fascia and
muscle are lowered from the previous site of adhesion and anchored to the tarsal plate.
a
b
a
b
c

III Blepharoplasty
236
will ensure that the levator muscle is well within the orbital
rim and will decrease the weight burden on the muscle.
Injecting fat into the orbicularis oculi muscle can be
e ective for a triple fold caused by an adhesion within a
super cial layer. In most cases, however, this cannot be rec-
ommended because of the problem with surface irregulari-
ties. Fat can be injected beneath the orbital septum if the
septum can be visualized by an incision. The graft survival
rate is relatively high, with minimal risk of surface irregu-
larity or lump formation with closed eyelids. It is, however,
not a widely practiced technique and may represent a chal-
lenge in terms of technical knowhow.
Blepharoptosis
In the immediate postoperative period, mild to moder-
ate blepharoptosis may simply be due to edema, which
is transient and will disappear. If a moderate to severe
blepharoptosis does not recede with edema, the surgeon
must suspect injury of the levator aponeurosis as a cause
(Fig. 18.25).
Another method to prevent re-adhesion is to create a
roll with the skin and orbicularis oculi muscle of the upper
ap. The method is to pass the needle through the skin
and orbicularis oculi just beneath the crease, then through
the orbicularis oculi and skin of the upper ap, creating a
slightly bunched kind of roll (Fig. 18.13).
Postoperative blepharoptosis can coexist with multiple
creases. In such cases, early corrective operation for ptosis
is e ective in separating the anterior and posterior layers,
which were previously adhered.5
Sunken Eyelid/Primary Triple Fold
Sunken eyelids occur from de ciency of orbital fat or soft
tissue and rarely from adhesion between super cial and
deep structures. For this reason, primary triple fold and
sunken eyelids can be thought of as a single clinical entity.
As such, treatment for sunken eyelid is similar to treatment
for primary triple fold.
The lost volume of soft tissue can be replenished by
fat injection, dermofat graft, or grafting of other soft tis-
sues such as muscle fascia (Fig. 18.23 and Fig. 18.24). Fat
injection to the subcutaneous layer or oculi muscle layer
can create irregularity in texture. Microfat injection in the
deeper plane between the orbicularis oculi muscle and the
septum reduces the potential for surface irregularity. How-
ever, injecting into the deeper layer has the potential for
levator muscle injury, which would result in blepharoptosis.
Injection into the ROOF can also cause blepharoptosis from
the added weight, although this is usually transient. Never-
theless, the risk of this complication can be minimized by
injecting the fat just above the periosteum while the upper
eyelid is pulled upward and the eyes are wide open. This
Fig. 18.23 (a) Preoperative sunken eyelid is (b) corrected with
microfat injection.
Fig. 18.24 Correction of sunken eyelid by dermofat graft. (a) A
sunken eyelid is marked on the left upper eyelid. (b) Intraoperative
view shows dermal fat before graft. (c) Postoperatively, the sunken
eyelid is corrected.
a
b
a
b
c

18 Management of Double-Eyelid Surgery Complications
237
If levator muscle injury is recognized, the surgeon should
consider which tissue to advance and by how much. This
advancement will stretch out the levator or the Müller muscle,
so it is important to assess the tension through the full thick-
ness of the levator mechanism. The injured tissues should
be approximated and plicated minimally so that the Müller
muscle is minimally stretched. If the injury was to the upper
septum with resultant adhesion, simply releasing the adhe-
sion may free the levator and correct the blepharoptosis.4,6
In iatrogenic blepharoptosis cases, the patient must
understand beforehand the goals and limitations of the
operation. The goal is to achieve a normal and symmetric
eld of vision on primary gaze. However, the levator muscle
may lack the normal range of motion from brotic changes,
and the patient must understand that lid lag or lagophthal-
mos can persist afterward.
Removal of the Eyelid Fold
Several facts must be presented by the surgeon, and those
facts should be understood by the patient before removal of
a surgically created eyelid fold. The rst is that a visible scar
will be present even when the eyes are open. The second
is that the fold can reappear with time. The third is that
the eyelid may appear and feel bulkier due to the scar tis-
sue, injection of fat graft, or inferior displacement of fat and
septum down to the area in risk of re-adhesion.6
Because of these potential issues, the authors usually
recommend an inner eyelid fold rather than total removal
of the eyelid fold. Inner eyelid folds are created in a man-
ner similar to the operation of correcting high creases. The
adhesion forming the existing crease is deconstructed, and
orbital fat and septum are interposed between the layers
to prevent re-adhesion. Eversion should be achieved dur-
ing skin closure. The incision site is taped for a minimum
of one week.

■Key Technical Points
1. To prevent loss of folds, the suture must be tied
while avoiding the intrusion of soft tissue between
the levator aponeurosis and dermis.
2. Correction of high crease can involve dissection
through either the pre-aponeurotic or pre-septal
layer. Despite the potential injury to the Müller
muscle or levator aponeurosis, the pre-aponeurotic
space is associated with lower rates of triple fold
formation and allows a ptosis operation.
3. Prevention and correction of triple fold are the
same: The surgeon must separate the anterior and
posterior lamellae by all means available—including
the interposition of orbital fat into this space.
The most common location at which the levator
mechanism is violated is at the junction between the leva-
tor aponeurosis and the upper border of the tarsal plate.
While soft tissue excision along the top margin of the tarsal
plate is necessary at times to induce dermotarsal xation,
removal of soft tissue superior to the tarsal plate can vio-
late the bers connecting the aponeurosis to the plate. The
resulting blepharoptosis may not be noticed in the imme-
diate postoperative period because of the edema and the
compensation by the Müller muscle. Over the next several
years, the Müller muscle undergoes mechanical failure
from the demand of opening the eyelid without the help
of the levator aponeurosis. This is the most likely scenario
for delayed blepharoptosis in patients who have had double
eyelid operations more than a decade ago.
The levator function test is especially important for
elderly patients. Compensating by brow elevation may also
mask minimal blepharoptosis. As stated previously, minor
unilateral blepharoptosis can easily be missed and become a
cause for unexpected postoperative asymmetry. Likewise, it
is important to distinguish between true ptosis (levator fail-
ure) and dermatochalasis (drooping skin) in elderly patients.
Fig. 18.25 Correction of postoperative blepharoptosis. (a) The
patient su ered from bilateral high fold and traumatic blepharop-
tosis following blepharoplasty. (b) Intraoperative nding of the
dehiscent levator aponeurosis from the tarsus. (c) Postoperative
photo.
a
b
c

III Blepharoplasty
238

■Case Studies
Case 1: Triple Fold and Ptosis
A 49-year-old female had undergone a double fold opera-
tion 11 years previously, which resulted in triple fold of
the right upper eyelid 3 months after the initial operation.
Recently, the patient had undergone upper blepharoplasty
to address the triple fold but experienced immediate post-
operative ptosis with persistent triple fold and eccentric
crease. On examination, the patient was found to have a
ptotic upper eyelid with partial pupil coverage on the right
side (Fig. 18.26a). The di erence in MRDs was 2 mm.
The patient consented and underwent an open upper
blepharoplasty with ptosis correction of the right eye. The
triple fold was addressed as described previously, with
adhesiolysis and interposition of fat between the anterior
and posterior lamellae. A bulky subcutaneous roll was cre-
ated with the orbicularis oculi muscle to increase fold resis-
tance above the newly established crease. The upper ap
was splinted with DuoDERM to prevent inward folding of
the skin. A postoperative photograph at 6 month demon-
strates resolution of the triple fold with acceptable sym -
metry of the upper eyelid margins (Fig. 18.26b).
Case 2: Triple Fold and Deep Fold
A 46-year-old female with a history of multiple upper and
lower blepharoplasties presented with various complica-
tions. Her history is most relevant for the double-eyelid
operation 3 months prior, with a high crease in the right
eye as the major complication. The patient underwent an
unsuccessful revision, and presented 2 weeks afterward.
On examination, the right eyelid was notable for multiple
creases and ptosis. The left eyelid fold was deep and showed
a slightly ectropic feature (Fig. 18.27a).
The recommendation was to correct the immediate
functional problem in the right eyelid and to address the
deep fold in the left eye at a later time. During the intraop-
erative exploration of the right lid, the levator aponeuro-
sis was found not to be in continuity with the tarsal plate.
The adhesions responsible for multiple creases were lysed,
and the medial septal fat was mobilized and interposed
between the anterior and posterior layers. The upper ap
was splinted w ith DuoDERM CGF upon skin closure. The
outcome was satisfactory. The ptosis was corrected, and the
majority of extraneous folds did not reappear. Six months
later, the patient underwent a successful blepharoplasty of
the left eyelid, with resolution of the deep fold and ectro-
pion (Fig. 18.27b).
Fig. 18.26 Case 1. Revision of triple fold and ptosis. (a) A 49-year-
old female patient presented with eccentric crease and ptosis of the
right upper eyelid after revision upper blepharoplasty. The patient
underwent adhesiolysis and interposition of septal fat between the
anterior and posterior lamellae. A bulky subcutaneous roll was cre-
ated with orbicularis oculi muscle to increase fold resistance above
the newly established crease. (b) Postoperative photograph at 6
months demonstrates resolution of the triple fold with acceptable
symmetry of upper eyelid margins.
Fig. 18.27 Case 2. Revision of triple fold and deep fold. (a) A
46-year-old female patient presented with a high, triple fold with
ptosis in the right eye and deep, slightly ectropic left eyelid after
multiple upper and lower blepharoplasties. In the right eye, the
adhesions were lysed and the medial septal fat was mobilized and
interposed between the anterior and posterior layers. Correction
of deep fold and ectropion of the left eye was done 6 months after
right eye surgery. (b) Six-month postoperative view shows resolu-
tion of the preoperative problems.
a
b
a
b

18 Management of Double-Eyelid Surgery Complications
239
References
1. Kim YW, Park HJ, Kim S. Secondary correction of unsatisfac-
tory blepharoplasty: removing multilaminated septal struc-
tures and grafting of preaponeurotic fat. Plast Reconstr Surg
2000;106(6):1399–1404, discussion 1405–1406
2. Chen WP. The concept of a glide zone as it relates to upper
lid crease, lid fold, and application in upper blepharoplasty.
Plast Reconstr Surg 2007;119(1):379–386
3. Kim YW, Park HJ, Kim S. Revision of unfavorable double
eyelid operation by repositioning of preaponeurotic fat. J
Korean Soc Plast Reconstr Surg 2000;27(2):99–104
4. Cho IC. The Art of Blepharoplasty. Seoul, South Korea:
Koonja Publishing; 2013:84–124
5. Lew DH, Kang JH, Cho IC. Surgical correction of m ultiple
upper eyelid folds in East Asians. Plast Reconstr Surg
2011;127(3):1323–1331
6. Chang SH, Chen WP, Cho IC, Ahn TJ. Comprehensive review
of Asian cosmetic upper eyelid oculoplastic surgery: Asian
blepharoplasty and the like. Arch Aesthetic Plast Surg
2014;20(3):129–139

■Conclusion
Complications after blepharoplasty are too numerous and
varied to allow a comprehensive discussion within this
chapter, but the basic principles of reconstructive surgery
are applicable to a majority of these complications. The
rst principle is to understand the normal and abnormal
function and anatomy of the eyelid. The second principle
is to undo, or deconstruct, the postoperative tissue changes
causing the complication. The third principle is to redo the
initial operation without making the same mistake.

(Trang không có chữ)

IV
Facial Bone Surgery

(Trang không có chữ)

243
19 Zygoma Reduction
Sanghoon Park and Jihyuck Lee

■Introduction
Asian people tend to have a shorter and wider facial contour
compared with Westerners. The prominent malar complex
combined with the protruding angled part of the lower jaw
creates a boxy rather than oval-shaped face. When viewed
from below, the at midface and wide cheekbones also
create a boxy appearance. These facial characteristics are
typical of the Mongoloid face (brachycephalic face), while
the Caucasian face is slim and protruding in an anterior-
posterior dimension (dolicocephalic face) (Fig. 19.1). Con-
ventional standards of beauty vary across di erent cultures
and ethnicities. However, aesthetic standards in the coun-
tries of East Asia have become more “global” and in uenced
by Caucasian standards. Asians seek a slimmer face with a
three-dimensional appearance.
This discrepancy in racial characteristics and changes
in beauty standards led to a rise in individuals desiring
to change their facial contour and shape. In East Asian
countries such as Korea, China, and Japan, facial contour-
ing surgery is very popular and commonly performed to
attain a more slender and smooth facial contour. Recently,
this trend has spread to other parts of Asia and among the
Asians living in Western countries.
However, simply changing the Mongoloid face into a Cau-
casian face does not guarantee a satisfactory result in Asian
countries, because Asians have di erent aesthetic goals and
di erent cultural backgrounds. For example, prominent high
cheekbones are considered a symbol of youth and admired
in Western countries. However, the same prominent cheek-
bones are considered aesthetically unpleasing for Asian
women as this feature gives a harsh, strong impression.
Therefore, before the surgery, surgeons should be well aware
of the goals of zygoma reduction in Asians.
Patients who seek zygoma reduction are those who
desire a slim and slender oval face when viewed from the
front. People with a brachycephalic face characterized by
a at forehead and midface describe their face as boxy in
shape. They desire a three-dimensional and voluminous
face. People with prominent high cheekbones complain
that they look “too strong,” “o ensive,” “old,” “tired,” and
“masculine,” and they want to change their faces to have a
more “soft,” “young,” and “feminine” appeal.
The objectives of zygoma reduction are as follows:
1. Reduction of facial width for slender facial contour.
First and foremost, the aim of zygoma reduction is
to acquire a more slender and narrow facial contour.
Usually facial width is determined by the bizygomatic
distance which links the articular tubercles on
the two sides. Reduction or transposition of the
zygomatic arch is an e ective method to reduce
facial width. As the zygomatic body is usually
hypertrophied together, reducing only the zygomatic
arch may lead to a boxy appearance; thus, combined
and harmonious reduction of arch width and
zygomatic body is essential.
Pearls
• The aim of zygoma reduction is to reduce the width
of the cheekbone, thus changing the boxy at facial
shape into a three-dimensional contour and achieving
a smooth, feminine facial line.
• Bizygomatic width and volume and the position
of the zygomatic body are the key variables to be
evaluated, and the amount of body ostectomy is
determined during the surgery.
• The zygomatic body and arch are usually moved
medially, posteriorly, and sometimes superiorly
during the surgery; the point of maximal malar
projection is marked and its new position carefully
planned.
• In zygoma reduction overall facial shape, including
mandible prominence and facial height, should be
considered. Caution should be taken for patients
with a long face, as there is a risk for the face to
appear longer after the surgery.
• Reduction malarplasty can be performed solely or in
combination with mandible reduction, genioplasty,
or forehead augmentation.
• Soft tissue plays a great role in reduction
malarplasty. In patients with abundant cheek fat, the
slimming e ect is less obvious and cheek drooping
is more probable.
• The following ve factors are considered high risk
for skin and soft tissue sagging: (1) over 40 years of
age, (2) abundant cheek fat, (3) thin skin and skin
laxity, (4) class II mandible or ill-de ned mandible
neck line, (5) deep nasolabial fold or jowl.

IV Facial Bone Surgery
244

■Patient Evaluation
Direct physical examination is the key process to evalu-
ate the patient’s problems and establish a surgical plan.
Clinical photos are necessary, as is radiologic examination
including frontal view, lateral view, submentovertex view,
and Waters’ view. A computed tomography (CT) scan with
3D view is also essential to evaluate the shape of the zygo-
matic complex.
The volume and position of the zygomatic body, and
the bizygomatic width are key variables to be considered.
The volume of the zygomatic body determines the amount
of ostectomy required during the surgery. If the volume is
large, a wider resection of the zygomatic body should be
planned. However, over-zealous reduction results in a at
or de cient look. Therefore, keeping an adequate volume of
the zygomatic body in the antero-posterior dimension and
transverse plane is essential.
The position of the zygomatic body is measured both at
its most lateral margin and in its maximal projection. The
outer margin of the zygomatic body is observed in conjunc-
tion with temple and cheek. To narrow the anterior mid-
facial width, the lateral margin of the cheekbone should
2. Change a boxy at facial shape into a three-
dimensional contour. Even if facial width is reduced,
the face can still appear square.1 Asian faces have
a brachyfacial characteristic with a at suborbital
area. When viewed from below, the lack of malar
projection results in the suborbital area and
zygomatic arch forming a 90-degree angle that lends
a boxy appearance. In this case, the face appears
at and two-dimensional, and even wider than it
appears from the front. Therefore, changes in the
shape and position of the zygomatic body are needed
to create a midface fullness that appears more three-
dimensional and youthful.
3. Attain a smooth facial line that looks more feminine
and young. An angular face line needs to be made
soft. In the case where the cheekbones protrude
outwardly, the facial line connecting the temple-
zygoma-cheek-mandible angle constitutes a very
convoluted line (Fig. 19.2). In the case of Westerners,
prominence of the zygomatic body is a symbol of
beauty and youthfulness. However, for Asians this
prominence results in an obstinate and masculine
look, which gives a negative impression. High
cheekbones are not an ideal look in Asian cultures;
therefore, reduction is needed to make the face soft
and feminine. For those over the age of 35, facial
soft tissue decreases and skin starts to droop; malar
eminence looks even more pronounced and causes
grooves in the cheek and temple, gradually resulting
in a tired and aged look. Fat injections to such hollow
areas can be an easy option, but the result is not
predictable or permanent. Zygomatic reduction is a
good option for the middle-aged woman who desires
a youthful, soft, and feminine facial contour.
Fig. 19.1 Bony facial morphology at the level of the cheekbone
in axial section. Compare the (a) dolicocephalic Caucasian face and
the (b) brachycephalic Asian face.
Fig. 19.2 Anterior and posterior facial contour lines. The anterior
facial contour line connects the temple, zygomatic body, cheek,
and mandible body (red line), while the posterior facial contour line
connects the temple, zygomatic arch, mandible angle, and chin
(blue line). If the anterior contour line is too convoluted, the patient
gives a “strong,” “o ensive,” “old,” “tired,” “masculine” impression.
The posterior contour line re ects the facial width and facial size.
a
b

19 Zygoma Reduction
245
Once the surgical variables for the zygomatic body are
evaluated, the bizygomatic width is measured, and the
required amount of arch medialization, which is critical in
the reduction of posterior facial width, should be decided.
The posterior basal portion of the arch, which is posterior
to the osteotomy, cannot be medialized and should be care-
fully shaved to prevent visible step. Too much arch reduc-
tion with the remaining zygomatic body will result in a at,
boxy face. To avoid this outcome and create a full midface
contour, the reduction of the zygomatic body and arch
should be coordinated and balanced.
There are many variables that need consideration dur-
ing surgery, and these should be decided by the above-
mentioned evaluation. Variables of the zygomatic body are
(1) amount of ostectomy, (2) amount of medialization, (3)
amount of setback, and (4) superior or inferior position-
ing. Variables of the zygomatic arch are the amount of arch
medialization and the shaving quantity of the posterior
area of the articular tubercle.
Facial soft tissue is an important aesthetic component
in zygoma reduction and should be considered before and
during the surgery. If the patient has thin fair skin with
minimal cheek fat, the changes after bone surgery will be
obvious and the chance of soft tissue drooping is minimal.
This patient is a good candidate for zygoma reduction.
However, bony step, especially around the orbit, may be
visible and the plate may be palpable through the thin skin.
Surgeons should take extra e ort to ensure a smooth tran-
sition between bony osteotomy. If the patient has abun-
dant cheek soft tissue, or thick skin, there is a high risk of
cheek drooping. The patient should be informed about the
possibility of cheek drooping and appropriate adjunctive
measures, including liposuction or lifting procedures. If the
patient has a thick malar fat pad, the zygomatic body should
be slightly over-corrected to prevent under-correction.
be trimmed or moved inward. If the outer margin of the
cheekbone is placed wide, the amount of narrowing and
medialization should be maximized and ostectomy should
be combined.
The point of maximal malar projection (MMP) is the
point where the outer contour of the zygomatic complex
protrudes most in the basal three-quarters view. If the
reduction of the zygomatic body is performed by shaving, or
the osteotomy is placed lateral to the MMP, this point stays
unchanged while the outer margin of the zygomatic body
is narrowed, resulting in an unnatural, box-shaped cheek-
bone. As stated before, the purpose of reduction malar-
plasty is not resection of the projection; therefore, adequate
projection and position of the MMP is the key postopera-
tive result. The point of MMP is marked and the surgeon
decides where to move this point three-dimensionally. The
amounts of medial repositioning and ostectomy are closely
related to the reduction of anterior facial width.
The ideal position of the MMP may vary among dif-
ferent ethnicities; however, the following are two simple
methods of determining the ideal position of the MMP
(Fig. 19.3).
1. Hinderer analysis. The MMP is determined at the
point of intersection of two lines, where the rst
line connects the lateral canthus and the oral
commissure, and the second line connects the nasal
alar base and the tragus line. The new location is a
point placed in juxtaposition to the crossed lines in
the upper outer quadrant.2
2. W ilkinson analysis. A line is dropped vertically
downward from the lateral canthus to the inferior
border of the mandible. The MMP is located at one-
third the distance from the lateral canthus to the
angle of the mandible.3
Fig. 19.3 Determining the ideal position of the maximal malar projection (MMP). (a) Hinderer analysis. (b) Wilkinson analysis.
a
b

IV Facial Bone Surgery
246
The approach for zygoma reduction can be simply
divided into two parts: the external approach (coronal inci-
sion, temporal incision, preauricular incision) and the intra-
oral approach. The external and the intraoral approaches
have their respective advantages and drawbacks.11
As zygomatic reduction developed from the treatment
of zygomatic fracture, the coronal approach was rst used
to expose the entire zygomatic body and arch. However, it
requires a long operation time, and it may cause bleeding
and visible scarring. The intraoral approach has the advan-
tage of hidden scars, limited bleeding, and short operation
time. However, it provides limited operative exposure,
resulting in di cult osteotomy, limited space for xa-
tion, and the risk of infra-orbital nerve injury. Side e ects
include cheek drooping due to wide dissection and volume
reduction, which can be avoided by minimizing the dissec-
tion. The osteotomized segment should be rigidly xed and
postoperative elastic dressing provided to prevent cheek
drooping. The intraoral approach can be used solely; how-
ever, it is usually combined with pre-auricular incision or
temple incision to minimize the dissection and the possi-
bility of cheek drooping.
Overall facial shape, including mandible prominence
and facial length, should be considered (Fig. 19.4). Zygoma
reduction can be performed solely or in combination with
mandible reduction. If the patient has a prominent mandi-
ble, reduction malarplasty alone may not be able to balance
bigonial and bizygomatic width, and combined mandible
reduction should be recommended. If a patient has a long
face with prominent cheekbones, a reduction in bizygomatic
distance deteriorates the excessively narrowed long face and
leads to “cucumber face.” It is advisable to focus on the set-
back of the zygomatic body instead of the medialization of
body and arch, and selectively create a soft facial contour.

■Surgical Techniques
The surgical technique and approach for zygoma reduction
was developed in 1983 when Onizuka et al4 introduced the
chiseling and shaving method for the protruding portion
of the malar bone via intraoral incision. Di erent surgical
techniques have been devised, such as bone shaving, in-
fracture of the zygomatic arch,5 and osteotomy/ostectomy
of the zygomatic body.2,6,7,8,9 Bone shaving is the simplest
and most straightforward method, and can be used for lim -
ited, localized protrusion of a zygomatic body. However,
shaving of the zygomatic body may lead to the exposure of
cancellous bone, resulting in unpredictable resorption and
postoperative irregularity10; thus, there is a limitation on
the amount of resection, and the overall size of the zygo-
matic body cannot be reduced with this method. Due to the
thickness of the instrument, the shaving method cannot be
applied to the zygomatic arch to reduce the overall facial
width.11 The in-fracture technique5 is a useful method in
reducing the protrusion of the zygomatic arch. Surgeons
usually conduct osteotomy of the zygomatic arch, avoid-
ing a full-depth cut and maintaining the continuity of
the periosteum (greenstick),10 and pushing the zygomatic
segments medially. Its major advantages are simplicity
and speed; however, it carries the risk of an uncontrolled
amount of in-fracturing in the zygomatic arch, and it has a
limited e ect on a prominent zygomatic body.
An L-shaped osteotomy of the zygomatic body is the
preferred method for patients with moderate to severe
malar protrusion due to wide zygomatic arch and promi-
nent body. An L-shaped osteotomy is made in the anterior
part of the zygomatic body and a separate osteotomy is
made in the posterior part of the zygomatic arch. With or
without removal of bone,6 a zygomatic segment is moved
to the desired position and xed w ith wires or plates and
screws. The L-shaped osteotomy technique can change
both the zygomatic body and arch and has the advantage
of controlling the degree of reduction as well as the shape
after reduction. As patients usually desire change in the
zygomatic body and arch, L-shaped osteotomy is currently
the most frequently used and preferred method in zygo-
matic reduction (Fig. 19.5).
Tr
Me'
Ft

Ft
Zy

Zy
Go'
Go'
Zy – Zy
Zy – Zy
Zy – Zy
Tr – Me'
Ft – Ft
Go' – Go'
= 70 – 75%
= 80 – 85%
= 70 – 75%
Fig. 19.4 Evaluation of facial harmony. Facial harmony should be
considered between midfacial width (Zy–Zy) and lower facial width
(Go′–Go′), and between midfacial width and upper facial width (Ft–
Ft). The ratio between the height (Tr–Me′) and the width of the face
should be in proportion.

19 Zygoma Reduction
247
the zygomatico-maxillary buttress. Great attention must be
paid to avoid injury to the orbital contents or infraorbital
nerve. A second, parallel line is drawn lateral to the rst line
to represent the strip of bone to be resected, allowing inset
of the fragment.12 The distance of the second line from the
rst line depends on the patient’s preference and the width
of the zygomatic body. A wider parallel osteotomy can be
made for greater reduction; however, the usual width of the
strip at the authors’ hospital is ~ 3 to 5 mm. The short limb
of the osteotomy must be high enough to avoid the dental
roots. Careful dissection is required in the zygomatic-ptery-
goid space to prevent injury to the vessel, which may lead to
profuse bleeding and postoperative bruising.
Multiple retractors are placed and the cuts are made
w ith a reciprocating saw starting from the superior lateral
limb of the osteotomy. Superior medial limb and nally
inferior transverse cuts are made, and the intervening bone
fragment is removed.
Posterior Osteotomy
Upon exposing the posterior part of the zygom atic arch,
the course of the frontal branch of the facial nerve and
the zygom atic arch is m arked on the skin. A ~ 1-cm verti-
cal incision is m ade w ithin the sideburn,12 2 to 3 cm ante-
rior to the tragus. This incision should lie posterior to the
course of the nerve. The arch is identi ed after the dis-
section of the periosteum , and ne elevators are passed
over the top and behind the arch and as far posteriorly as
possible to ensure that the osteotomy is still anterior to
the temporom andibular joint. A reciprocating saw is used
to m ake this vertical osteotomy. When the posterior oste-
otomy is completed, the zygom atic segm ent should be
free to m ove w hile rem aining attached to the m asseter.
Additional bone distal to the osteotomy m ay be burred if
necessary.12
Fixation
The osteotomized body and arch are positioned posteriorly
and medially as a result of the osteotomy, and the interven-
ing segment is removed. According to the patient’s desired
outcome and preoperative planning, the three-dimensional
location of the segment is determined while good contact
of bony surfaces is maintained. Six-hole miniplates with
screws are placed to x the anterior portion of the segment,
and two- or three-hole miniplates with screws are used to
x the zygomatic arch (Fig. 19.6). Positioning of the osteot-
omized segment is the most critical step for postoperative
results, and the nal segment position is adjusted based on
pre-existing asymmetry and intraoperative appearance to
achieve the desired nal outcome. An identical procedure
is then performed on the contralateral side. Standard tech-
niques are used to close the intraoral and skin incisions.
As the intraoral approach is the most widely used
method these days, zygoma reduction via the intraoral
approach with an L-shaped osteotomy is the most pre-
ferred method to correct facial imbalance in patients with
prominent zygomatic body and arch.
Anesthesia and Approach
All patients are given general anesthesia. Orotracheal intu-
bation is preferred at the authors’ hospital, but nasotracheal
intubation can be used. A ~ 3-cm labiobuccal vestibular inci-
sion is made on each side of the maxilla.7 Through this inci-
sion, the soft tissues are elevated superiorly and laterally at
the subperiosteal plane. Dissection is limited to the area of
the zygomatic body, the anterior wall of the maxillary sinus,
and the lateral and inferior orbital rim. As the dissection
extends superolaterally over the malar eminence, a portion
of the origin of the zygomatic major and zygomatic-cuta-
neous ligaments may be partially divided from the bony
surface.
Anterior Osteotomy
An inverted L-shaped osteotomy line is marked over the
malar eminence (Fig. 19.5). This line generally extends
medially from the lateral border of the orbital rim to just
below the infraorbital foramen. Be careful not to start the
osteotomy too low from where the arch changes from a
vertical to a horizontal direction, which may result in insuf-
cient volume reduction in the zygomatic body. The short
limb of the osteotomy then turns at about a 90° angle toward
Fig. 19.5 Design of bone cuts in malar reduction. An inverted
L-shaped osteotomy line is marked over the malar eminence. A sec-
ond, parallel line is drawn lateral to the rst line to represent the
strip of bone to be resected. A posterior bone cut is made ~ 2 to 3
cm anterior to the tragus.

IV Facial Bone Surgery
248
Ostectomy versus Osteotomy
In patients with a oversize zygomatic body, repositioning
the zygomatic body alone can neither slim the overall face
nor smooth the midface contour. Therefore, a patient who
has prominent zygomatic body requires the appropriate
ostectomy and reduction of bony volume together. How-
ever, as ostectomy may lead to accidental bony gap, sur-
geons must take great care that ostectomy is carried out in
the sagittal dimension as much as possible and maximize
the bone-to-bone contact to prevent the bony gap.
Vector of Transposition
Repositioning of the osteotomized zygomatic complex is
the single most important step in reduction malarplasty.
The MMP point is determined before surgery through thor-
ough consultation and physical examination.
If the patient’s chief complaint is facial width, the zygo-
matic segment should be transposed medially, and if patients
seek improvement in a prominent zygomatic body to give
a less harsh impression, the zygomatic complex should be
transposed medially and posteriorly, with more reduction in
the zygomatic body than in the zygomatic arch. By control-
ling the amount of transposition of the zygomatic body and
arch, and by combining the medial and posterior transposi-
tions, a harmonious and balanced face can be attained.

■Key Technical Points
Shape of the Osteotomy: “I” versus “L”
There are two main osteotomy patterns used for the zygo-
matic body: I-shaped osteotomy and L-shaped osteotomy.11
Baek et al13 described I-shaped osteotomy as a technique to
remove the malar complex. This osteotomy is placed lat-
eral to the maximal malar projection and usually cannot
include the volume of malar projection. The osteotomized
segment may drift downward as the masseter muscle pulls
the fragment.
The L-shaped osteotomy, w hich evolved from the
I-shaped osteotomy, has the key advantage of including
the volum e of the m alar projection. Fragm ent displace-
m ent is avoided and the m asseter m uscle cannot drag the
fragm ent dow nward because of the countercheck of the
inferior border.11 Furtherm ore, the L-shaped osteotomy
has a larger contact surface than the I-shaped osteotomy.
The greatest advantage of the L-shaped osteotomy is from
the aesthetic point of view, as the osteotomy is e ective
in reducing the w idth of the zygom atic body and repo-
sitioning the MMP point. For m axim izing the degree of
reduction, the authors choose to position the superior
osteotomy line as close to the orbital rim as possible. Care
m ust be taken to avoid injury to intraocular and perior-
bital structures.
Fig. 19.6 Rigid xation of malar complex using two miniplates.
(a) Applying a prebending miniplate to the zygomatic arch.
(b) Applying miniplates to the zygoma body.
a
b

19 Zygoma Reduction
249
Nonunion
Nonunion is a source of under-correction and cheek drooping,
and is one of the reasons for unidenti ed pain in long-term
follow-up. Though radiology can reveal breakage of xation
material and separation of bony segments, examinations may
at times be unable to detect de nite signs of malunion. Partial
separation of bone, especially in the supero-lateral position
of the orbital rim, is often found but is not considered non-
union if one-third of the bone is healed in continuity. Possible
causes of nonunion are excessive resection of bone, unstable
xation, excessive movement (e.g., when chewing), muscle
pull, and trauma in the immediate postoperative period. Con-
servative treatment can be tried initially to relieve pain and
camou age soft tissue depression. Soft tissue depression can
be corrected with fat injections, although frequent relapse
can occur. In cases of repeated relapse after fat injection,
onlay Medpor (Stryker) insertion to create continuity over
the gap is an option. Indications for major surgery include a
severe recurrent pain, and aesthetic problems such as obvi-
ous bony gap, asymmetry, and sagging of the malar complex.
Repositioning of the zygoma complex is ideal, though very
di cult if bone loss is extensive, and additional bone graft or
alloplastic material may be necessary.
Infraorbital Nerve Injury and
Paresthesia
During zygomatic reduction, injuries to the orbit, orbital
contents, infraorbital nerve, and temporal bone are possi-
ble. To prevent injury to these structures, the surgeon must
be careful and acutely aware at all times regarding the loca-
tion of the saw.12 Excessive pull by retractors are a com -
mon source of paresthesia after surgery. Plate and screws
may cause the paresthesia if they are placed too close to the
infraorbital foramen.
Trismus
Compression of the temporalis muscle due to inward
movement of the zygomatic arch can cause trismus. It will
improve within 1 to 2 months after surgery, and mouth
opening exercises are helpful to relieve those symptoms.
Asymmetry
As most patients who complain of asymmetry postopera-
tively already had asymmetry prior to surgery, a careful
and thorough preoperative examination is critical, followed
by communication regarding the possibility of asymmetry
and limitations of surgery.
Fixation
Although xation may not be essential in malar reduction
using the in-fracture method, rigid xation is necessary
when one or more osteotomies are conducted. Only rigid
xation to both the zygomatic body and arch can guaran-
tee precise repositioning and stability. If rigid xation is
not used after osteotomy, under-correction, asymmetry, or
relapse after surgery can occur. It is a serious shortcoming
that surgeons are unable to control the exact degree and
position of movement, especially in the eld of aesthetic
surgery. Rigid xation is also critical to prevent nonunion
and postoperative pain.
As the masseter muscle functions as a depressor and
a medial rotator for the zygomatic segment after oste-
otomy, three-point xation is necessary for the zygomatic
body, orbital rim and zygomatic arch to prevent three-
dimensional rotation. However, xation in the orbital rim
requires additional incision. To avoid additional incision
and xation in the orbital rim, the authors recommend
using double-square midplate in the zygomatic complex as
a very simple and easy method to prevent rotation while
minimizing the incisions.

■Complications and
Their Management
Sagging of Soft Tissue
As reduction m alarplasty involves reduction of bone as
well as transposition, sagging of soft tissue m ight be
inevitable and needs to be addressed during the pro-
cedure. Previously, an inferiorly positioned zygom atic
complex or m obile bone segm ent was a m ajor cause of
soft tissue sagging. This complication can be prevented
by rigid xation.
Wide dissection and excess soft tissue are potential
reasons for sagging of soft tissue. Minimizing the dissection
and preserving the origin of the masseter muscle in the
zygomatic body can minimize unwanted soft tissue prob-
lems. The status of soft tissue also plays a role in soft tissue
sagging. High-risk factors for skin and soft tissue sagging
include (1) age over 40 years, (2) abundant cheek fat, (3)
thin skin and skin laxity, (4) class II mandible or ill-de ned
mandible neck line, and (5) predisposing deep nasolabial
fold or jowl. In these high-risk groups of patients, preopera-
tive explanations about the possibility of cheek drooping
are necessary, and special attention should be paid before
and during the procedure to try to overcome this complica-
tion. Midface lift, thread lift, buccal fat removal, and para-
nasal augmentation are helpful adjunctive procedures and
can be combined or performed separately.

IV Facial Bone Surgery
250

■Case Studies
Case 1: Zygoma Reduction
A 32-year-old woman complained of prominent zygoma
and wide midface (Fig. 19.7). An inverted L-shaped ostec-
tomy with a 5-mm reduction of each zygoma was conducted
to reduce the protrusion of her zygoma. The posterior part
of the zygomatic arch was divided with complete ostec-
tomy. After the osteotomized zygoma was shifted medially
(5 mm) and posteriorly (3 mm), it was xed with mini-
plates and screws. The body of the zygoma was xed with a
double-bridged plate to provide stability against the torque
from the masseter muscle. The arch of the zygoma was
xed with a pre-bending plate to achieve an accurate posi-
tion as well as stability (Fig. 19.8). The malar prominence
and midfacial width were reduced markedly at 12 months
postoperatively (Fig. 19.9).
Under-correction
From the patient’s aesthetic point of view, the most com -
mon complaint after zygomatic reduction is under-cor-
rection. Inadequate reduction of the zygomatic body or
inappropriate positioning of the maximum malar pro-
jection is a common cause for dissatisfaction. Therefore,
proper patient selection is required and patients’ expecta-
tions should be realistically addressed and adjusted.
Fig. 19.7 Case 1. Preoperative (a) frontal
and (b) oblique photographs of the patient.
a
b

19 Zygoma Reduction
251
Fig. 19.8 Case 1. (a) Preoperative and (b) postoperative radiographic showing posteromedial repositioning of the zygoma.
Fig. 19.9 Case 1. Twelve-month postopera-
tive (a) frontal and (b) oblique photographs.
a
b
a
b

IV Facial Bone Surgery
252
(Fig. 19.11). After complete ostectomy was applied to the
anterior and posterior part of the zygoma, the zygoma
was repositioned posteriorly and medially. Narrowing
genioplasty and concomitant mandible contouring surgery
were performed to correct her square lower face. Fourteen
months after the operation, the patient’s facial contour
appears soft and slender (Fig. 19.12).
Case 2: Combined Zygoma Reduction
and Mandible Contouring
A 28-year-old woman complained of malar protrusion and
prominent mandibular angle (Fig. 19.10). She underwent
reduction malarplasty and mandible contouring surgery
Fig. 19.10 Case 2. Preoperative (a) frontal, (b) oblique, and (c) basal photographs. Zygoma reduction and mandible narrowing surgery
were done simultaneously.
Fig. 19.11 Case 2. Three-dimensional CT images: (a) preoperative and (b) 8 months postoperative
a
b
c
a
b

19 Zygoma Reduction
253
7. Kim YH, Seul JH. Reduction malarplasty through an in-
traoral incision: a new method. Plast Reconstr Surg 2000;
106(7):1514–1519
8. Agban GM. Augm entation and corrective m alarplasty. Ann
Plast Surg 1979;2(4):306–315
9. Uhm KI, Lew JM. Prominent zygoma in Orientals: classi cation
and treatment. Ann Plast Surg 1991;26(2):164–170
10. Kook MS, Jung S, Park HJ, Ryu SY, Oh HK. Reduction m alar-
plasty using m odi ed L-shaped osteotomy. J Oral Maxillo-
fac Surg 2012;70(1):e87–e91
11. Hong SE, Liu SY, Kim JT, Lee JH. Intraoral zygom a reduc-
tion using L-shaped osteotomy. J Craniofac Surg 2014;
25(3):758–761
12. Morris DE, Moaveni Z, Lo LJ. Aesthetic facial skeletal
contouring in the Asian patient. Clin Plast Surg 2007;
34(3):547–556
13. Baek SM, Chung YD, Kim SS. Reduction m alarplasty. Plast
Reconstr Surg 1991;88(1):53–61
References
1. Kang JS, ed. Plastic Surgery. Seoul, Korea: Koonja; 2004
2. Hinderer UT. Malar implants for improvement of the facial
appearance. Plast Reconstr Surg 1975;56(2):157–165
3. Wilkinson TS. Complications in aesthetic m alar augm enta-
tion. Plast Reconstr Surg 1983;71(5):643–649
4. Onizuka T, Watanabe K, Takasu K, Keyama A. Reduction ma-
lar plasty. Aesthetic Plast Surg 1983;7(2):121–125
5. Yang DB, Park CG. Infracture technique for the zygomat-
ic body and arch reduction. Aesthetic Plast Surg 1992;
16(4):355–363
6. Cho BC. Reduction m alarplasty using osteotomy and repo-
sitioning of the m alar complex: clinical review and com -
parison of two techniques. J Craniofac Surg 2003;14(3):
383–392
Fig. 19.12 (a–c) Case 2. Fourteen-month postoperative photographs.
a
b
c

254
20 Mandible Reduction
Sanghoon Park and Seungil Chung
lateral protrusion of the m andibular angle rather than
soft tissue contribution such as hypertrophied m asseter
m uscle.1,2 Anthropologic studies have show n signi cant
quantitative facial anthropom etric di erences am ong
di erent ethnic backgrounds; one such di erence being
that Koreans, in comparison to Caucasians, tend to have a
m ore developed lower face.3 In addition, the average bigo-
nial distance in Caucasian wom en is 105 to 109 m m ,4,5
whereas in Korean wom en the average distance is 118 to
125 m m .3 Since Koreans have a greater bigonial distance
and m ore ared m andibular angle, they often undergo
m andible reduction to slenderize the lower facial contour,
whereas Caucasians prefer m andible augm entation to
correct weak jaw lines.6

■Introduction
The overall Asian facial structure is typically classi ed as
brachycephalic or mesocephalic, with a widened mandibu-
lar arch and broad lower facial skeleton. In countries such
as Korea, China, and Japan, these characteristics are often
viewed as masculine and unattractive; thus, both men and
women often wish to make their faces appear more slim
and slender.
The w idth of the lower third of the face is determ ined
by the w idth of the m andible itself, which is surrounded
by m uscles and subcutaneous fat tissues. Generally, the
cause of prom inent m andibular angle in Asians is the
Pearls
• “Angle reduction” is the old name for this procedure
and represents a major misconception regarding
what the surgery is for. The purpose of mandible
reduction is to make the lower face appear slim in
the frontal view and to achieve a smooth contour in
the lateral view. Changing the mandibular plane and
contouring the whole lower border of the mandible
are critical steps. On the other hand, angle reduction
with removal of triangular bone will inevitably leave
an unnatural lower contour of mandible with a
secondary angle.
• Because shaping the lateral contour of the mandible
alone may result in minimal improvement in the
frontal view, surgical techniques to reduce the width
of the lower face via burring or ostectomy of the
lateral cortex should usually also be done.
• The chin plays an important role in creating a
beautiful facial line and overall contour; therefore,
genioplasty should be considered in continuity with
mandible reduction.
• The relationship between the maxilla and the
mandible in pro le view should be observed. In
class II, or class III pro le, orthognathic surgery
is rst considered. However, in patients with
mild deformity, or in patients who do not want
orthognathic surgery, mandible reduction should
be planned to prevent the existing problems from
deteriorating.
• The inferior alveolar nerve is the most important
structure during mandible reduction, and it should
be carefully examined preoperatively in panoramic
view as well as in a computed tomography (CT)
scan. It is typically located at least 20 mm away from
the upper border of the mandible, which should be
kept in mind when designing and conducting the
osteotomy. The most common cause of paresthesia
is not a direct cut but a blunt injury to the nerve
by retractors coming out of the mental foramen.
Osteotomy should be conducted at least 3 mm away
from the mental foramen.
• The incidence of m ajor intraoperative hem orrhage
has decreased due to advances in surgical
technique and the use of a hypotensive anesthetic
protocol. If the retrom andibular vein or the
facial artery is torn during a procedure, adequate
hem ostasis w ith electrocautery m ay not be
easy, and this m ay lead to excessive blood loss.
Application of hem ostatic substances and external
m anual compression for m ore than 30 m inutes can
help to stop the bleeding.
• Following the completion of surgery, the soft tissues
of the cheek and the neck should be checked for any
signs of bleeding or swelling. Any sign of swelling or
bleeding near the throat is a serious complication
and should be treated immediately as it may cause
breathing problems.

20 Mandible Reduction
255
modifying the shape of the chin, in conjunction with man-
dible reduction, is essential to achieve a slimmer and oval-
shaped contour.12,13,14 The authors’ current techniques for
a prominent mandible are (1) controlling the slope of the
mandibular plane by resecting the mandibular angle and
controlling the inferior border of the body via a long curved
resection technique, (2) reducing the width of the lower
face via burring or ostectomy of the lateral cortex, and (3)
narrowing genioplasty according to the patient’s speci c
demands. Since the authors introduced the technique in
2008, simultaneous performance of narrowing genioplasty
and mandible reduction has been widely called “V-line sur-
gery” since the shape of the contoured jaw line looks like
the letter V (Fig. 20.1).
V-line surgery not only narrows the width of the man-
dible and contours the jaw line, but also reduces the size
and controls the position of the chin in both the vertical
and anterior-posterior directions, making a smaller and
more feminine oval facial contour possible.
On the basis of technical perfection, the establishment
of appropriate surgical indications for each technique is
mandatory to achieve aesthetically pleasing results. Anal-
ysis of the individual’s entire face should come from a
thorough understanding of lower facial types. The authors
classify the shape of the lower face according to the shape
of the chin, which is helpful in establishing the treatment
plan (Fig. 20.2).15

■Patient Evaluation
Diagnosis
The condition may easily be diagnosed by clinical ndings
and radiologic examination. The degree of protrusion of the
mandible, asymmetry, masseter muscle hypertrophy, and
amount of the subcutaneous fat should be evaluated. The
degree of hypertrophy of the masseter muscle can be iden-
ti ed by palpating the tightened versus relaxed status of
the jaw. Hyperostosis, mostly around the mandible angle,
is noted in the radiologic studies. Two-thirds of the cases
Resection of the Mandibular Angle
In 1949 Adams introduced a surgical technique for resecting
mandibular bone and masseter muscle via the transcutane-
ous approach, and Converse performed the same procedure
through an intraoral approach in 1959.7 In 1989 Baek intro-
duced mandibular angle reduction for Asian patients via
the intraoral approach. In 1991 Yang and Park introduced
a surgical technique for contouring the mandibular body
and the symphysis with a sequential resection of the bone.
Since the late 1990s one-stage, long curved ostectomy has
been widely used to contour the mandible.8
Narrowing the Width
The conventional ostectomy, which resects the inferior bor-
der of the mandibular angle and body, can bring a satisfac-
tory contour from the side view; however, it fails to show
improvement in the frontal facial contour due to its inabil-
ity to narrow the broad lower face. To achieve the desired
appearance of the frontal view facial contour, a variety of
surgical techniques were developed. In 1997, Deguchi et
al reported that the width of the lower face could be nar-
rowed by a technique that shaves the lateral cortex anterior
to the inferior alveolar nerve and splits the angle posterior
to the nerve.9 In 2001 Han and Kim e ectively reduced
the bigonial width through lateral cortex ostectomy with-
out a mandibular angle reduction.10 In 2004, Hwang et al
introduced simultaneous utilization of the two di erent
techniques.11
Creating an Ideal Shape and
Adding Dimension to a Flat Face
Although the previously mentioned mandible reduction
techniques have many advantages, they fail to correct the
broad and blunt appearance of the chin. The chin is a major
determinant of an attractive lower facial contour. Thus,
the authors have reported that narrowing the width and
Fig. 20.1 Mandible reduction surgery has evolved from (a) simple resection of the angular portion to (b) contouring of the total man-
dible shape as the desire for a slim and small face has increased. Recently, (c) narrowing genioplasty was introduced to achieve a slim and
oval-shaped jaw using the conventional surgical method.
a
b
c

IV Facial Bone Surgery
256
be identi ed. The ideal gonial angle is within the range of
105 to 115 degrees, and the MP-SN angle is 30 to 40 degrees.
After measuring and understanding the accurate balance of
the upper and midface, the amount of reduction, lengthen-
ing, and vertical/horizontal advancement or retrusion (set-
back) of the mandible in the anterior-posterior direction
will be determined.
Transverse Plane
Three-dim ensional CT or the cervical-vertex view is
used to identify the transverse shape of the m andible
(Fig. 20.3). The angle of divergence and convexity of the
m andible are observed. In cases w ith an inward-curled
angle w ith a convex transverse shape, sagittal resection
of the body w ill help to reduce the w idth of the m andible
m ore e ectively.
show mild to moderate increase in bigonial distance due to
lateral aring of the mandible angle. However, the remain-
ing third shows total mandibular hypertrophy and accentu-
ated square contour of the whole lower face.
The shape and width of the lower face in the frontal
view can be classi ed as in Fig. 20.2. The pro le as well as
the height of the chin should be taken into consideration.
The status of soft tissue including muscle and fat should be
considered as well.
Preoperative Evaluation and
Surgical Planning
The author routinely obtains a patient’s photographic
documentation and radiologic examination that includes
panoramic view, skull lateral view, postero-anterior (PA)
cephalogram, and 3D CT image. For precise surgical planning
and prevention of postoperative asymmetry, three-dimen-
sional analysis of the photographs and the radiographs in
the frontal, sagittal, and transverse planes is important.
Examination of the shape and symmetry and understand-
ing the overall balance of the face are mandatory.
Frontal Plane
Using the PA cephalogram and 3D CT, the degree of pro-
trusion or aring of the mandible angle, symmetry, con-
vexity of the body, deviation, and shape of the chin should
be examined. The amount of narrowing and lateralization
(considering the degree of asymmetry), and the amount
of angle and inferior border resection are determined
after checking the course of the inferior alveolar nerve. A
panoramic view is helpful in determining the amount of
ostectomy of the mandibular angle and body, as well as the
position of its ostectomy line.
Sagittal Plane
Using the lateral cephalogram, the gonial angle, the man-
dibular plane–sellar nasion angle (MP-SN angle), and the
vertical and anterior-posterior position of the chin should
Fig. 20.2 The shapes of the lower face in the frontal view are diverse. Because the chin should be designed based on the individual
patient’s preference, this classi cation system helps patients to compare the shapes of the chin and consult with the surgeon in detail.
Fig. 20.3 Analysis of the transverse plane. The exact region and
amount of sagittal resection can be determined by thorough eval-
uation of the angle of divergence and convexity of the mandible
from this view.

20 Mandible Reduction
257
Asymmetry
Dental occlusion and overall facial conformation should
be considered to analyze asymmetry of the face. Special
care should be taken if a mismatch is observed between
the actual photographs and the radiographs. If facial asym -
metry is due to skeletal factors, the degree and extent of
asymmetry should be evaluated. If there is canting due
to maxillary vertical discrepancy, then the patient should
fully understand the limitations of mandibular contour-
ing surgery. Mandibular asymmetry of mild to moderate
degree can be improved by disproportionate resection of
the mandible border and elaborate three-dimensional
shaving. Asymmetries con ned to the chin relative to the
face are most frequently encountered. For individuals
whose chin shifts to one side, mandible reduction makes
the chin asymmetry more obvious, and concomitant hori-
zontal osteotomy of the chin and transverse movement
may be required.
Soft Tissue Contribution
A hypertrophied m asseter m uscle, which is a critical fac-
tor for determ ining the w idth of the face, should be cor-
rected. Generally, detachm ent of the m asseter from its
insertion to the m andible alone can reduce the volume of
the m uscle, and additional resection of the m uscle is not
recom mended. In cases w ith severe hypertrophy of the
masseter m uscle, botulinum toxin injection or a partial
resection of the m edial aspect of the masseter m uscle can
be done. However, this increases swelling and the risk of
nerve injury or in am m ation by necrotic m uscle debris.
Buccal fat removal m ay be combined for excessive cheek
fat. A lifting procedure is required for skin and soft tissue
sagging, after checking the patients’ age and skin elasticity.
The high-risk factors for skin and soft tissue sagging are
(1) age over 40, (2) abundant cheek fat, (3) thin skin and
skin laxity, and (4) class II occlusion or ill-de ned m an-
dible neck line.
Ethnic Variation and Cultural Background
The ideal facial shape m ay di er depending on personal
preference, as well as ethnic or cultural background. Espe-
cially when consulting patients with di erent national or
ethnic backgrounds, careful attention should be paid to
their ideal or desirable facial shape. For example, Chinese
patients prefer a pointed chin, Japanese prefer a round
chin, and Koreans prefer a m oderately trapezoidal chin. In
the case of fem inization surgery for transgenders, to sat-
isfy their special needs, m axim izing the feminine charac-
teristics, rather than simply reducing the w idth and size of
the m andible, is essential.
Consideration in Surgical Planning
The Chin
The term chin refers to both the bone and the surround-
ing soft tissues. The chin is a very important component in
lower facial morphology, and full attention should be given
to the procedure of lower facial contouring surgery. In some
patients, resection of the mandible alone does not make the
face appear slender. This is mainly attributed to a wide, at
chin and a U-shaped lower facial morphology. Therefore, to
create a slim and attractive face, reducing the width of the
chin and modifying its shape and position is necessary in
addition to resection of the mandible. The amount of central
resection should be individualized depending on the width
of the chin and the patient’s need. In the authors’ practice,
resection of the central strip ranges from 6 to 12 mm (aver-
age 9.1 mm). In most cases, this amount of resection pro-
duces the desired shape and width of the chin. Advancement
or setback (retrusion) of the chin should also be considered if
a change of pro le is required. The ideal aesthetic chin posi-
tion should be determined in the pro le view, considering
the positions of the nasal tip and the upper and lower lip.
However, critical decisions with regard to the chin position
are made when viewing the patient “face to face,” consider-
ing the varying perspectives in repose and with broad smile.
Abnormal Skeletal Relationship between
the Maxilla and Mandible
The relationship of the mandible with the maxilla should be
understood, because not all patients have a normal inter-
maxillary skeletal relationship. In cases with protruding
mandible showing class III occlusion, or those with relative
underdevelopment of the lower jaw showing class II occlu-
sion, orthognathic surgery may be needed to improve this
disorder. If mandibular contouring surgery is to be done
without correcting class II or class III skeletal problems, cer-
tain characteristics should be considered to avoid aggravat-
ing the intermaxillary problems. In cases with prominent
mandible showing a skeletal class III relationship, a long jaw
line may appear more accentuated if the angle is resected
too much during mandible reduction. Therefore, the angle
should be conservatively resected and sagittal shaving
should be properly performed to minimize aggravation of
prognathic appearance. In patients with a retruded man-
dible showing a class II pro le, excessive resection of the
mandible angle causes a more obscure cervico-facial line.
Therefore, conservative mandible resection and maximal
sagittal shaving of the body of the mandible, combined
with advancement genioplasty are recommended. In a long
face, angle resection should be performed in a limited way
to prevent the aggravation of steep mandibular plane.

IV Facial Bone Surgery
258
of a curved ostectomy may be extended to just below the
mental foramen depending on a patient’s facial morphol-
ogy. Simultaneous reduction of the mandibular angle and
body can result in a much smaller lower facial contour.
Tangential Ostectomy with a Reciprocating
Saw (Lateral Cortex Ostectomy)
This procedure removes the external cortex of the mandib-
ular ramus by means of a reciprocating saw. It is performed
to narrow the bigonial distance in the laterally ared angles
of the mandible or to reduce the thickness of the body of
the mandible in the frontal view.9,10,11 However, this pro-
cedure is not recommended due to the high risk of nerve
injury, soft tissue adherence to the bony medulla, and di -
culty in shaping. The authors recommend sagittal resection
with burring, leaving a thin lm of outer cortex, in which it
is easy to control the shape of the mandible and a natural
healing process is ensured.
General Procedure
In Korea most mandibular angle reduction is performed by
long curved ostectomy using intraoral incision with burr-
ing. If patients want a more V-line chin, the authors add the
narrowing genioplasty procedure.12 The general procedure
is as follows (Fig. 20.5):
1. Mandibular reduction is performed under general
anesthesia. Either nasotracheal or endotracheal
intubation can be used. The authors generally use
endotracheal intubation with a tube anchored in the
rst premolar teeth with a 3–0 nylon suture.
2. The patient is positioned supine with a transverse
roll beneath the shoulders to extend the neck. The
entire face is prepped with betadine solution. The

■Surgical Techniques
Approach: Intraoral versus
External Approach
Mandible angle reduction can be done using the intra-
oral approach or the external approach. Traditionally,
mandible angle ostectomy has been performed using the
intraoral approach with an oscillating saw.16 This approach
involves minimal space to work along with poor visibility,
and it requires technical skill in manipulating the oscil-
lating saw. Because somewhat blind removal of the man-
dible is required, ostectomy may be facilitated by burring
the ramus area or by using indirect mirrors, especially in
patients with inwardly curved angles.
An external approach was previously used because
it was easy and allowed direct access to the mandibu-
lar angle.17 The external approach can be used with chin
incision or postauricular incision. With the postauricular
approach, scar is hidden and the operation time is shorter.
Because poor visibility of the anterior part of the mandible
causes unsatisfactory outcomes, this approach should be
applied only to a limited population of patients who have
mandible angle prominence.
Types of Ostectomy: Curved Ostectomy
versus Tangential Ostectomy
See Fig. 20.4 for the two types of osteotomy.
Curved Ostectomy with an Oscillating Saw
This procedure can be applied to most patients with prom -
inent mandibular angle.8 It reduces the postero-inferior
mandibular angle in the lateral view. The anterior extent
Fig. 20.4 Types of ostectomy for mandible reduction. (a) Curved ostectomy with an oscillating saw. (b) Tangential ostectomy with a
reciprocating saw (lateral cortex ostectomy).
a
b

20 Mandible Reduction
259
5. Using a specialized angle retractor, the mandibular
angle is hooked, and the desired level of the
osteotomy line is marked on the bone with a
marking pencil. The marked line is then checked
w ith dental mirrors.
6. Usually, a long curved ostectomy is performed. A
110-degree oscillating saw is used for the ostectomy.
We use a set of oscillating saws of di erent lengths.
If the ostectomy is done with full thickness, the bone
segment moves freely. When patients request angle
reduction, the authors employ the curved ostectomy
technique, and for a V-line face, a long curved ostectomy
technique with narrowing genioplasty is performed.
7. After the ostectomy, the attachment of muscle to the
medial part of the mandible usually remains. A large
elevator or Bovie electrocautery is used to divide
any remaining medial pterygoid muscle bers from
the medial surface of the osteotomized segment,
allowing its removal.
8. Finally, a high-speed bur is used to remove any
additional bone from the lateral cortex and to make
a smooth transition. This procedure prevents the
chance of secondary angle.
9. An identical procedure is performed on the
contralateral side. Here any preoperative asymmetry
in the degree of angle prominence should be taken
into account and a relatively greater or lesser amount
of mandibular bone resected.
oral cavity and the teeth are brushed with dilute
aqueous betadine solution. The operative eld is
draped to assist with intraoperative evaluation of
symmetry. Surgery is performed in the intraoral area
in a dark eld; hence, wearing a headlight is helpful
in performing the surgical procedure.
3. A rubber opener is placed between the upper and
the lower teeth. The incision line is designed using a
gentian violet solution. A buccal vestibular incision
design is made from the ramus extending anteriorly
to the rst molar or second premolar while leaving
a 7- to 8-mm mucosal cu . This mucosal cu helps
to close the suture in an easy manner. The operative
eld is in ltrated with 0.25% lidocaine with
1:200,000 diluted epinephrine solution.
4. Through a subperiosteal elevation with the
periosteal elevator, the lateral aspect of the
mandibular body is exposed. The dissection
continues superiorly along the vertical ramus
to adequately expose the area of resection. The
masseter bers are stripped from the lower border
of the body, angle, and posterior border of the ramus
with an angle stripper to secure a good operative
eld. Subperiosteal dissection prevents bleeding
from the masseter muscle. During the dissection the
mental nerve, the marginal mandibular branch of
the facial nerve, the retromandibular vein, and the
facial artery should be protected.
Fig. 20.5 Operative procedures. (a) The incision line is designed. (b) Subperiosteal elevation with periosteal elevator. The lateral aspect
of the mandibular body is exposed. (c) The desired level of the osteotomy line is marked on the bone with a marking pencil. The marked
line is checked by using dental mirrors. (d) A long curved ostectomy is performed. A 110-degree oscillating saw is used for the ostectomy.
(e) Dividing the attachment of muscle to the medial part of the mandible. A large elevator or Bovie electrocautery is used to divide any
remaining medial pterygoid muscle bers from the medial surface of the osteotomized segment.
a
b
c
d
e

IV Facial Bone Surgery
260
determined preoperatively, depending on the width of chin
and the patient’s desire. The two segments are approxi-
mated centrally and xed with microplates and screws.
Advancement of the two segments is also possible if cor-
rection of the pro le is required. The resection of the cen-
tral strip ranges from 6 to 12 mm.
Postoperative Care
After the surgery, the patient’s vital signs are monitored to
ensure stability 4 to 6 hours postoperatively. The patient
may drink water after stability has been con rmed; this
progresses to a liquid diet. To reduce swelling or bleed-
ing, the patient is put in a semi-Fowler position. Generally,
patients are hospitalized for one night after the surgery.
Blood drainage tubes are kept for one night to drain pos-
sible bleeding from the operation site.

■Key Technical Points
1. Important anatomic structures must be respected.
Previous anatomic study has demonstrated that the
inferior alveolar nerve typically courses at least 20
mm away from the upper border of the mandible,
which should be kept in mind when designing the
osteotomy. As a rule of thumb, the osteotomy line
should be at least 1 inch (2.5 cm) away from the
upper border of the mandible at the rst molar.
2. The surgeon accurately determines the position and
quantity of mandibular bone to be removed through
a combination of clinical assessment, experience,
and knowledge of mandibular anatomy.
3. The superior limit for resection is the occlusal
plane; the anterior limit is the convergence of the
mandibular oblique line with the lower mandibular
border.
4. The resected segment typically has an elongated
semilunar shape instead of being triangular; when
removed, it leaves a gently curved lower mandibular
border. The oblique height of this segment is
typically in the range of 10 to 20 mm, with length
ranging 30 to 70 mm.
5. If an osteotomy is too straight and fails to form a
smooth transition, it will leave a “secondary angle.”
The secondary angle can be palpated or sticks out
externally. If secondary angle is obvious, it may
require burring or an additional osteotomy.
10. The bilateral wounds are irrigated by saline and
hemostasis secured. The wounds are closed in
two layers (periosteum and mucosa) w ith a 4–0
absorbable suture. Bilateral suction drains are left in
place overnight. Compression with a facial bandage
is used.
Combined Narrowing Genioplasty
Narrowing genioplasty, either as a single procedure or in
combination with mandible reduction, makes the lower
face appear slender or produces a more feminine chin con-
tour.12 The soft tissue attachment of the chin is maintained
to produce a maximum narrowing e ect and to maintain
blood ow to the bony segments. A horizontal osteotomy
and two vertical osteotomies are designed as shown in
Fig. 20.6. The amount of resection in the central segment is
Fig. 20.6 (a,b) Narrowing genioplasty combined with mandible
reduction is required in patients with wide or blunt chin, and it
greatly improves the slimming e ect in mandible reduction. A hori-
zontal osteotomy and two vertical osteotomies are designed. The
central segment is resected, and two lateral segments are approxi-
mated centrally and xed with miniplates and screws.
a
b

20 Mandible Reduction
261
the osteotomy to become vertical as it courses posteriorly
up the ramus, as this may cause a ramus, subcondylar, or
condylar fracture. Such fractures are treated as described
elsewhere, using open reduction with internal xation or
intermaxillary xation as indicated.19
Infection and In ammation
Though wound infection follow ing surgery is uncommon,
problematic issues may arise due to the following condi-
tions: poor pre- and postoperative oral hygiene, improp-
erly sealed wound, insu cient ushing, bone fragments
or dust left behind in the wound, damaged salivary glands,
or periodontal disease. To prevent the risks of postopera-
tive infection, intravenous antibiotics are administered on
admission. After discharge, oral antibiotics are prescribed
to the patient.
Unfavorable Aesthetic Outcomes
Caution should be taken to avoid removing too much bone
from the jaw line, or else the contour may appear too sharp
or the cheeks may look too hollow. Prior to surgery, the
design of the osteotomy should be carefully planned, and
accurately measured and marked so that the procedure is
performed without any complications.20 Fat grafting may be
performed to cover and camou age any areas of over-correc-
tion. Changes in the skeleton are re ected favorably or unfa-
vorably by the overlying soft tissues. Careful preoperative
facial analysis of both hard and soft tissues will maximize
favorable aesthetic outcomes.21 Other complications unique
to mandible reduction are best dealt with by prevention.

■Case Studies
Case 1
A 20-year-old woman complained of her prominent man-
dibular angles (Fig. 20.7). She desired a slender and smooth
lower facial contour. The intergonial distance was large,
and this, in combination with lateral aring of the angle,
made her lower face appear broad, square, and strong. After
a full-thickness ostectomy of a lower border of the man-
dibular body-angle region, shaving of the outer cortex was
accomplished (Fig. 20.8). After the mandible contouring
surgery, the gonial angle and the mandibular plane angle
increased (Fig. 20.9). Ten months following the operation,
the contour of her lower face appeared soft and slender
(Fig. 20.10).

■Complications and
Their Management
Hemorrhage and Hematoma
The incidence of major intraoperative hemorrhage has
decreased over the years, principally because of advances
in surgical technique and the use of hypotensive anes-
thetic protocols (mean systolic blood pressure of 65 mm
Hg). Hypotensive anesthesia coupled with injection of local
anesthetic with vasoconstrictor minimizes blood loss and
increases visualization of the operative eld. If the retro-
mandibular vein or facial artery is torn during the proce-
dure, attempts to secure hemostasis often fail because
electrocauterizing the bleeding vessel is not easy. Unsuc-
cessful hemostasis may lead to excessive blood loss. Appli-
cation of a hemostatic substance like Surgicel (Ethicon) or
external manual compression for at least 30 minutes can
help to stop the bleeding.16 Following the completion of
surgery, the soft tissue of the cheek and the neck should
be checked for any signs of bleeding or swelling. Any signs
of swelling or bleeding near the throat should prompt
extreme awareness and alarm because it may cause a
breathing problem, possibly leading to a fatal outcome.
Nerve Injury
If the curved osteotomy is made too high on the mandibu-
lar body, the inferior alveolar nerve may be injured. Prior
to surgery, a panoramic X-ray is taken to locate and check
the course of the inferior alveolar nerve. The surgeon must
accurately de ne the course of the inferior alveolar nerve
during the surgery by measuring its course from the lower
border of the mandible. The osteotomy should be at least 3
mm away from the inferior alveolar canal and mental fora-
men.18 Special care should be taken when performing oste-
otomy cuts, and drilling should be accompanied by copious
irrigation to prevent heat injury. If it appears that the nerve
has been damaged or amputated, then a 7–0 nylon neuro-
rrhaphy needs to be performed to secure possible recovery
of the nerve.
Fracture
During an angle reduction, a precise ostectomy around the
posterior border of the mandible is important to avoid a
condylar fracture. When using the oscillating saw, adequate
periosteal dissection is essential to adequately visualize the
posterior mandibular border. The surgeon must not allow

IV Facial Bone Surgery
262
Fig. 20.7 Case 1. Preoperative (a) fron-
tal and (b) oblique photographs of the
patient.
Fig. 20.8 Case 1. Bone fragments resected by ostectomy.
Fig. 20.9 Case 1. Cephalograms (a) before and (b) after the surgery.
a
b
a
b

20 Mandible Reduction
263
and screws were used for xation. To obtain a smooth cur-
vature of the mandibular lower border, the marginal part
of the mandibular body-angle region was trimmed using
an oscillating saw and bur (Fig. 20.12). After mandibular
contouring surgery, the patient requested correction of her
malar prominence and underwent reduction malarplasty.
Twenty months following the rst operation, the contour of
her lower face appeared soft and slimmer (Fig. 20.13).
Case 2
A 25-year-old female with an angulated lower face wanted
to make her facial contour slender, smooth, and “egg
shaped” (Fig. 20.11). A complex genioplasty combined with
mandibular contouring was performed. The complex genio-
plasty consisted of 8 mm horizontal reduction, 2 mm verti-
cal reduction, and centering genioplasty. Absorbable plates
Fig. 20.10 Case 1. Ten-month postopera-
tive photographs. Postoperative (a) frontal
and (b) oblique.
Fig. 20.11 Case 2. Preoperative (a) frontal
and (b) oblique photographs of the patient.
a
b
a
b

IV Facial Bone Surgery
264
Fig. 20.12 Case 2. Bone fragments resected by ostectomy:
(a) mandibular contouring; (b) zygoma reduction.
Fig. 20.13 Case 2. (a) Frontal and (b) oblique
postoperative photographs of the patient at
twenty months after mandible reduction and
eleven months after malar reduction.
a
b
a
b

20 Mandible Reduction
265
angulated, which made her look muscular. She underwent
mandible and zygoma reduction surgery simultaneously.
After the mandible contouring surgery, the gonial and man-
dible plane angle increased (Fig. 20.15). Six months follow-
ing the operation, the contour of her lower face appeared
soft and slimmer (Fig. 20.16).
Case 3
A 20-year-old woman requested that her prominent man-
dibular angle and zygoma be corrected (Fig. 20.14). The
zygomatic complex was protruded and the mandible was
Fig. 20.14 Case 3. Postoperative (a)
frontal and (b) lateral photographs of the
patient.
a
b

IV Facial Bone Surgery
266
Fig. 20.15 Case 3. Three-dimensional CT scans (a,b) before and (c,d) after the surgery.
a
b
c
d

20 Mandible Reduction
267
12. Park S, Noh JH. Importance of the chin in lower facial con-
tour: narrowing genioplasty to achieve a feminine and slim
lower face. Plast Reconstr Surg 2008;122(1):261–268
13. Lee TS, Kim HY, Kim T, Lee JH, Park S. Importance of
the chin in achieving a fem inine lower face: narrowing
the chin by the “mini V-line” surgery. J Craniofac Surg
2014;25(6):2180–2183
14. Lee TS, Kim HY, Kim TH, Lee JH, Park S. Contouring of the
lower face by a novel m ethod of narrowing and length-
ening genioplasty. Plast Reconstr Surg 2014;133(3):
274e–282e
15. Park S. Classi cation of chin in term s of contour and width
and preference in Korean. Paper presented at: 61st Annual
Meeting of Korean Society of Plastic Surgery; 2007:355
16. Neligan PC. Principles. In: Neligan PC, ed. Plastic Sur-
gery. Vol. 1, 3rd ed. Seattle, WA: Elesevier Saunders;
2012:179–183
17. Morris DE, Moaveni Z, Lo LJ. Aesthetic facial skel-
etal contouring in the Asian patient. Clin Plast Surg
2007;34(3):547–556
18. Lo LJ, Wong FH, Chen YR. The position of the inferior alveo-
lar nerve at the m andibular angle: an anatomic consider-
ation for aesthetic mandibular angle reduction. Ann Plast
Surg 2004;53(1):50–55
19. Hwang K, Han JY, Kil MS, Lee SI. Treatment of condyle frac-
ture caused by mandibular angle ostectomy. J Craniofac
Surg 2002;13(5):709–712
20. Jin H, Park SH, Kim BH. Sagittal split ram us osteotomy with
m andible reduction. Plast Reconstr Surg 2007;119(2):
662–669
21. Hsu YC, Li J, Hu J, Luo E, Hsu MS, Zhu S. Correction of square
jaw with low angles using mandibular “V-line” ostectomy
combined with outer cortex ostectomy. Oral Surg Oral Med
Oral Pathol Oral Radiol Endod 2010;109(2):197–202
References
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2. Yang DB, Park CG. Mandibular contouring surgery for
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m iddle face in young Korean women. J Korean Soc Plast Re-
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skeleton. Perspect Plast Surg 1988;1:23–69
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6. Whitaker LA. Aesthetic augm entation of the posterior
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8. Gui L, Yu D, Zhang Z, Changsheng LV, Tang X, Zheng Z. Intra-
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Fig. 20.16 Case 3. Six-month postopera-
tive (a) frontal and (b) lateral photographs
of the patient.
a
b

268
21 Aesthetic Orthognathic Surgery
Seong Yik Han and Kar Su Tan
there has been an emerging trend of performing a two-jaw
surgery (maxillary Le Fort I operation with mandibular
setback) on patients with normal occlusion for purely cos-
metic reasons. In the authors’ opinion this is unacceptable.
Surgeons must be wary of the commercialization of medi-
cine and of the ne line between ethics and economics, and
never lose sight of the sacred nature of their job.
During orthognathic surgery’s history of more than
170 years, many surgeons have tried to set the concept of
operation to achieve these purposes.1,2 Technically, the site
and design of osteotomy, the approach for the osteotomy
(extraoral or intraoral), the method for xation (with wire
or with plates and screws), and the emergence of the bone
expansion and distraction osteogenesis techniques are
among the innovations (Fig. 21.1).3,4,5 Since 1960 orthog-
nathic surgery has made rapid progress alongside the
advancements in technology such as the xation plate and
screw system for rigid xation. Information technology (IT)
development with software and 3D cone beam computed
tomography (CT) and printing technology also have con-
tributed to the improvement of analysis and diagnosis.
To approach orthognathic surgery, an understanding of
the basic concept of occlusion is crucial since restoration

■Introduction
“Orthognathic surgery” literally means “correctly (ortho-)
positioned jaw (gnathic).” It refers to the surgical correc-
tion of abnormal mandible, maxilla, or both. Abnormal
dentofacial development or asymmetry may not only
result in an unaesthetic face and functional deteriora-
tion, but also can lead to psychosocial problems. Thus the
objective of this surgery is to restore both function and
aesthetics. Functional restoration refers to reinstating the
functions of occlusion, mastication, swallowing, temporo-
mandibular joint (TMJ) function, speech, and phonation.
Aesthetic improvement involves the re-establishment of
facial symmetry and harmony. The former should always
be prioritized over the latter. Ultimately, it is hoped that the
functional and aesthetic improvement will encourage the
resolution of any psychosocial issues.
In the authors’ decades of experience with more than
3600 orthognathic surgical cases, 96% percent of the patients
reported that they overcame their inferiority complex fol-
lowing orthognathic surgery. Their new-found con dence
could be seen on their faces a month after surgery. Recently,
Pearls
• Orthognathic surgery is a dual-pronged operation
that ful lls both functional and aesthetic goals
through repositioning of the maxilla and/or
mandible via orthodontic and surgical manipulation.
Functional restoration should take precedence over
aesthetic considerations.
• The psychological impact of orthognathic surgery
should be emphasized in the preoperative
evaluation. It is recommended that signi cant others
attend the preoperative discussion with the patient.
• Understanding of malocclusion is important for
proper functional rehabilitation. However, restoring
normal occlusion does not necessarily ensure a good
aesthetic outcome.
• Pure orthodontic compensation treatment is
sometimes about moving the teeth in the opposite
direction to the surgical movement. Hence, it
is important for the orthodontist to be able to
recognize which patients will eventually require
surgery, and thus avoid a painful detour to a trial of
orthodontics that produce no bene t.
• Temporomandibular joint positioning should be
assessed rst as the condylar position is the key
reference point of the mandible. Masticatory muscle
function and facial nerve function should also be
checked before treatment.
• High sagittal supraforaminal osteotomy is superior
to sagittal split ramus osteotomy not only because it
requires a shorter operating time, has less bleeding
tendency, and is less invasive, but also because it has
the lowest risk of inferior alveolar nerve injury.
• Adequate soft tissue protection, meticulous
hemostasis, rigid xation, proper preoperative
planning, and good surgical skills are the key tenets
for a successful facial bone surgery.
• “Aged appearance” can result from the relaxed midfacial
soft tissue following LeFort I or bimaxillary surgery, and
may require additional aesthetic procedures.

21 Aesthetic Orthognathic Surgery
269
The modern interpretation of Angle’s classi cation is
con ned mainly to the anterior-posterior relations (on the
sagittal plane), omitting information on the vertical and
transverse planes. In practice, the ideal occlusion can be
described as having (1) class I molar and canine relation-
ship; (2) no crowding, no spacing, no rotation; (3) overjet
~ 2 to 4 mm; (4) correct crown angulation and inclination;
(5) at and slight upward curve of Spee; and (6) upper and
lower midlines that are in alignment. Malocclusion should
be analyzed w ith respect to intra-arch and inter-arch
problems. Intra-arch problems are related to individual
teeth—sagittally and vertically rotated, or transpositioned.
Inter-arch problems are related to the intermaxillary prob-
lems, which occur on three planes: (1) class II or III maloc-
clusions in the sagittal plane; (2) cross-bite, scissor bite, or
midline shift in the transverse plane; and (3) deep bite or
open bite in the vertical plane.

■Patient Evaluation
The goal of consultation is to determine what a patient
wants (chief complaints) and his or her concerns regard-
ing function and aesthetics. Past medical and dental history
(especially orthodontic treatment) is particularly important.
The psychological state of the patient should also be evalu-
ated during the interview. If the patient appears to have
to normal occlusion is the overriding priority of all orthog-
nathic surgeries. It is therefore of utmost importance that
the surgeon rst be well informed on what constitutes nor-
mal occlusion. In normal occlusion, the mesiobuccal cusp
of the upper rst molar is received in the groove between
the mesial and distal buccal cusps of the lower rst molar.
Anteriorly, the upper canine should occlude between the
lower canine and rst premolar. Angle classi ed the maloc-
clusion into three classes with respect to the dental align-
ment and interrelationship of maxillary and mandibular
arches and bones (dento-skeletal) (Fig. 21.2).4 Class I mal-
occlusion is de ned as having a normal molar occlusion
between the upper rst and lower rst molars but prob-
lems w ith the other teeth, such as rotation or malposition-
ing. Class II malocclusion involves cases where the lower
rst molar is occluded distal to the upper rst molar. This
is subdivided into two divisions: Division 1 is where the
upper incisors are proclined, increasing the overjet; divi-
sion 2 is for cases with retroclined incisors, with reduced
overjet. Class III malocclusion describes the lower rst
molar as being occluded mesial to the upper rst molar.
According to Angle’s classi cation, it was found that class
I is the most common occlusion pattern across all races.
However, Japanese persons were found to have a signi -
cantly greater percentage of class II relationships (15%),
while class III relationships are highest among the Chinese
population (34%).6
Blair (1907)
Perthes (1924)
Schlössmann (1922)
Schuchardt (1954)
Trauner & Obwegeser
(1975)
Obwegeser & Dal Pont
(1958)
Fig. 21.1 The development of the mandibular ramus osteotomy technique. Blair, Schlössmann, and Perthes performed osteotomy via
the external oral approach, Schuchardt and Obwegeser used the intraoral approach, and Perthes (1924) is known to be the rst to perform
a sagittal osteotomy on the ascending ramus. The intraoral sagittal spit ramus osteotomy was rst performed by Obwegeser (1953), and
Dal Pont modi ed Obwegeser’s procedure to enlarge the contacting surfaces.

IV Facial Bone Surgery
270
facial height is the distance between the soft tissue nasion
and menton. The facial width is de ned by the bizygomatic
width—the distance between the outermost points of the
soft tissue zygomatic arch. The bitemporal width and bigo-
nial width should approximate 80 to 85% and 70 to 75% of
the bizygomatic width, respectively (refer to Fig. 19.4).
Lip projection is also a determining factor of facial aes-
thetics. Asians usually have distinctive characteristics of
the lip due to a combination of thickness, bimaxillary pro-
trusion, and labioversion of the upper and lower incisors.
The ideal upper lip should be balanced with the nose and
cheek, and the lower lip should be slightly posterior to the
upper lip. The amount of teeth exposure depends on the
vertical height of the maxilla. When both lips are in repose,
the vermillion of the lower lip should be ~ 25 to 30% more
exposed compared with the upper lip. This is especially
important for orthognathic surgery for a cleft lip-palate
patient. When smiling, the incisors should be at least three-
quarters exposed yet not exceed 2 mm of gingival show. A
gummy smile, or excessive gingival show during smiling, is
not a reliable indicator of the adequacy of maxillary height.
Finally, facial symmetry can be assessed based on several
relationships, involving the midsagittal plane through the
nasal tip, midline of the upper and lower incisors, midline
of the symphysis of the chin, and the gonion position of
either side. Dynamic symmetry can be assessed by observ-
ing the level of the oral commissures and teeth exposure
on smiling. Occlusal plane canting should also be assessed.
Cephalometric analysis is crucial for identifying the
patient’s skeletal and dental problems for corrective surgical
planning and postoperative assessment. Standard reference
points on a cephalometric X-ray image and basic propor-
tions are shown in Fig. 21.4 and Fig. 21.5. Cephalometric
data analysis reveals that there exists some disparity in
certain parametric values between Asians and Caucasians
obsessive-compulsive tendencies, extra care should be taken
before the surgery. The psychological impact of orthogna-
thic surgery should be discussed with the patient before
surgery. It is recommended that signi cant others, including
family members, also attend the preoperative discussion. In
bimaxillary protrusion patients, who have the greatest risk
of postoperative “aged face,” it is wise to warn them about
the possibility of additional aesthetic procedures because of
the increased skin redundancy after surgery.
Docum entation of any temporom andibular joint (TMJ)
symptom s such as clicking, deviation on m outh opening,
and associated headaches should be recorded. In particu-
lar, pre-existing TMJ dysfunction prior to surgery should
be addressed before orthodontic treatm ent, as the con-
dylar position is the key reference point of the m andible.
The range of m otion and any deviation on m outh open-
ing should be carefully docum ented. Masticatory m uscle
function and facial nerve function should also be checked
before treatm ent.
Harmony and symmetry are the key factors determin-
ing facial aesthetics, even though it should be recognized
that what de nes a beautiful face can di er according to
sociocultural factors. In the frontal view, the face can be
divided equally into the upper third (trichion to glabella),
middle third (glabella to subnasale), and lower third (sub-
nasale to menton) (Fig. 21.3a). Vertically the frontal plane
is composed of equal fths (rule of fths) (Fig. 21.3b).
The central fth is the distance between the medial
canthi (which is equivalent to the alar base width). The
outer two- fths is the distance between the outer canthi
and the outermost point of the ear. A vertical line from
either outer canthus indicates the ideal vertical posi-
tion of the gonion (mandibular angle) on both sides. The
facial height-to-width ratio (facial index) is optimal when
it approaches 1.35:1 for males and 1.3:1 for females. The
Fig. 21.2 Angle’s classi cation of malocclusion. (a) Class I malocclusion. (b) Class II malocclusion. Mandible is in a retruded position
compared with the maxilla. (c) Class III malocclusion. Protrusion of the mandible with mesial occlusion of the lower teeth is observed.
a
b
c

21 Aesthetic Orthognathic Surgery
271
Tr
G'
Sn
Me'
1/3
1/3
1/3
1/3
2/3
1/5

1/5

1/5

1/5

1/5
Fig. 21.3 Aesthetic facial division on frontal view. (a) The face can be divided equally into the upper third (trichion to glabella), middle
third (glabella to subnasale), and lower third (subnasale to menton). (b) Vertically, the face is divided into equal fths (rule of fths).
Por
S
G'
N
N'
Or
PNS
Go
Ar
UIA
ANS
A
Pr
Sn
A'
Ls
LIE
UIE
Li
B'
B
LIA
Pog
Pg'
Gn
Me
M'
Fig. 21.4 (a,b) The skeletal, dental, and soft tissue reference points in cephalometry (see Table 21.1 for key).
a
b
a
b

IV Facial Bone Surgery
272
(Fig. 21.6).6,7,8 These di erences account for the characteris-
tics features in facial morphology observed in these ethnic
groups. Important observations in Asians include (1) more
vertical growth tendency (downward grow th); (2) upper
and lower incisors that are are more labially inclined, giving
the lip a more protrusive appearance; (3) facial pro les that
are more convex, especially in the middle third of the face
(between points A and B); (4) more acute nasolabial angle;
(5) signi cantly shorter distance between the upper lip and
E-line (UL–EL) and lower lip and E-line (LL–EL). No statisti-
cally signi cant di erence was observed in reference angles
like sella-nasion-A point angle (SNA), sella-nasion-B point
angle (SNB), A point-nasion-B point angle (ANB), and men-
tolabial angle across all the ethnic groups (Fig. 21.6).
With the advent of new technology such as cone beam
computed tomography (CBCT) and 3D processing software,
we are currently on the verge of transitioning from the 2D
era into 3D. But cephalometric analysis is still useful today
and forms the foundation of our understanding of the facial
metrics. A dental model is also important in providing
information on the arch form (arch width and arch length),
teeth position, upper and lower molar relation, and teeth
inclination. It also gives a rough simulation of postoperative
upper and lower jaw relationships.
N
ANS
Me
S
N
A
B
E line
G
Sn
St
Li
Me'
1/2
1/2
1/2
1/2
1/3
2/3
Fig. 21.5 Basic proportions, angles, and lines in cephalometric anal-
ysis of the face. (a) The nasion (N)–anterior nasal spine (ANS)/ante-
rior nasal spine (ANS)–menton (Me) ratio is the most frequently used
parameter to assess the adequacy of the vertical height of the chin.
(b) The “esthetic line” (E-line, Ricketts line) is drawn from the nasal tip
(pronasale) to the soft tissue pogonion (Pog′) to evaluate lip position.
(c) The ideal ratio of the distances Sn–St:St–Me′ is 1:2 and that of the
distances Sn–Li:Li–Me′ is 1:1. S, sella; Me′, soft tissue menton; St, sto-
mion; A, A point, subspinale; B, B point, submentale; G, glabella; Sn,
subnasale; and Li, Labrale inferior.
Fig. 21.6 Disparity of parametric values of cephalometry among
Asians and Caucasians.8 Asians (dotted line) show a higher vertical
growth tendency and a more convex pro le compared with Cauca-
sians (solid line). The nasolabial angle is more acute in Asians and
the upper incisors are more labially inclined, giving the upper lip a
more protrusive appearance. The lower anterior teeth are also labi-
ally inclined to the mandibular plane in Asians.
a
b
c

21 Aesthetic Orthognathic Surgery
273
Table 21.1 Reference points in cephalometry
Skeletal reference points
N
Nasion
Most anterior point of nasofrontal suture
S
Sella
Center of sella turcica
Or
Orbitale
Most inferior point on orbital margin
A
A point, subspinale
Deepest point of anterior border of maxilla
B
B point, submentale
Deepest point of anterior border of mentum
Pog
Pogonion
Most anterior point of mentum
Gn
Gnathion
Midpoint between Me and Pog
Me
Menton
The lowest point of symphysis
ANS
Anterior nasal spine
Most anterior point of nasal oor
PNS
Posteror nasal spine
Most posterior point on hard palate contour
Ar
Articulare
Intersection of sphenoidal basis and condylar posterior border
Go
Gonion
Most inferior, posterior point on mandibular angle
Por
Porion
Uppermost point on bony external auditory meatus
Dental reference points
UIE
Upper incisor edge
Incisal point of upper incisor
UIA
Upper incisor apex
End point of root of incisor
LIE
Lower incisor edge
Incisal point of lower incisor
LIA
Lower incisor apex
End point of root of lower incisor
Soft tissue reference points
Tr
Trichion
Hairline at the forehead middle line
G′
Soft tissue glabella
Median point between eyebrows (most anterior point of forehead)
N′
Soft tissue nasion
Deepest point on skin at root of nose
Pr
Pronasale
Most anterior point of tip of nose
Sn
Subnasale
Transitional point of nasal septum and upper lip
A′
Soft tissue A point
Deepest point between subnasale and upper lip
Ls (UL)
Labialis superior (upper lip)
Most anterior point of upper lip
St
Stomion
Middle point between upper and lower lips
Li (LL)
Labialis inferior (lower lip)
Most anterior point of lower lip
B′
Soft tissue B point
Deepest point between lower lip and chin
Pog′
Soft tissue pogonion
Most prominent point of soft tissue chin
Me′
Soft tissue menton
Most inferior point of chin

IV Facial Bone Surgery
274
located at the upper part of the ascending ramus should be
kept unless it will constantly spill into the surgical eld for
the rest of the surgery.
The periosteum is incised with diathermy and elevated
o the ascending ramus, retromolar area, and rst molar
region laterally and buccally. Elevation of the periosteum
is also done medially between the sigmoid notch and lin-
gula around the mandibular foramen. Periosteal elevation
should extend up to the posterior margin to allow instru-
ments to be inserted and to protect the soft tissue at the
posterior margin during osteotomy. Prior to elevation of
the lingual periosteum of the ascending ramus, in ltration
of epinephrine and lidocaine is helpful to avoid accidental
rupture of nutrient vessels emerging from the bony fora-
men. After soft tissue protection is ensured, bone cutting
begins with a 3.1- or 4-mm round bur at the anterior bor-
der of the ascending ramus. The cortex at the anterior bor-
der is removed carefully up to the rst marrow bleeding
point. At this point, in ltration of epinephrine/lidocaine is
performed again before continuing the next step.
Lingual cortex osteotomy is done with a 2.7-mm round
bur. Soft tissue protection is ensured with a narrow chan-
nel retractor or broad curved periosteal elevator. Special
care should be taken not to injure the inferior alveolar
nerve and vessels. The authors usually keep the dissection
area narrow to avoid damage to the vessel and nerve at the
mandibular foramen. The lingual cortex osteotomy is car-
ried to the posterior border of the ascending ramus.
Buccal cortex osteotomy should be designed depend-
ing on whether the objective is to achieve setback, advance-
ment, or transverse rotation of the mandible. This can
range from a vertical osteotomy near the rst molar area
to an oblique line running from the second molar to the
mandibular angle. Once again, adequate protection is nec-
essary to avoid injury to the facial artery and the marginal
mandibular branch of the facial nerve.

■Surgical Techniques
In patients with slight malocclusion and no cosmetic con-
cerns, it is reasonable not to o er any treatment. But in
cases of skeletal discrepancy of the facial bones, surgery
might be the most useful modality of treatment. For Asian
patients, the authors prefer Le Fort I osteotomy, high sagit-
tal supraforaminal osteotomy (HSSO), anterior segmental
osteotomy (ASO), and genioplasty. Table 21.2 summarizes
the appropriate operations for the respective diagnoses.
Typically, the orthognathic surgery is performed under
general anesthesia with nasotracheal intubation. Inten-
tional hypotension and perioperative antibiotic coverage in
most cases is mandatory.
Surgery of the Mandible
Sagittal Split Ramus Osteotomy (SSRO)
Among the various techniques of mandibular osteotomy
proposed so far, sagittal split ramus osteotomy (SSRO), after
the Obwegeser–Dal Pont method, is the most widely adopted
technique. It is generally indicated in horizontal mandibular
excess or de ciency, or cases of mandibular asymmetry.9
First, mark the midline that runs from the glabella
along the nasal dorsum, down the philtrum and the mid-
line of the upper lip and upper incisors, through the mid-
line of the lower incisors to the midline of the symphysis.
This line is helpful as a reference during and after surgery.
Mucosal incision starts from the buccal vestibule of the
lower rst molar and continues along the anterior margin
of the ascending ramus laterally (Fig. 21.7a). Meticulous
soft tissue dissection to the periosteum with proper hemo-
stasis will guarantee safe bone surgery. The buccal fat pad
Table 21.2 Categorization of orthognathic surgery by diagnosis
Diagnosis
Appropriate operation
Mandibular protrusion
Mandibular setback (SSRO or BVSRO) + genioplasty
Maxillary protrusion
Le Fort I
Mandibular vertical excess
Genioplasty
Maxillary vertical excess
Double jaw surgery
Mandibular retrusion
SSRO
Mandibular vertical de ciency
SSRO + genioplasty
Open bite
Double jaw surgery or Le Fort I only
Bimaxillary protrusion
ASO + genioplasty or upper ASO and lower SSRO + genioplasty
Abbreviations: ASO, anterior segmental osteotomy; BVSRO, bilateral vertical sagittal ramus osteotomy; SSRO, sagittal split ramus osteotomy.

21 Aesthetic Orthognathic Surgery
275
try. The condylar head is checked to m ake sure it is in
a good and stable position in the glenoid fossa. Once
everything is confirm ed to be in position, osteosynthe-
sis is perform ed. There are two m ethods of osteosyn-
thesis according to the level of fixation. The first, rigid
fixation w ith utilization of titanium plates and screws
or lag screws, results in absolute stabilization of the
two bone segm ents. There is no m ovable gap and pri-
m ary bone healing occurs w ith m inim al callus form a-
tion. The second, nonrigid fixation w ith w ires, perm its
intersegm ental m obility. The w ire’s m ain action is to
lim it distraction of the two segm ents w hile secondary
bone healing takes place. Despite being nonrigid, this
form of fixation is accepted as being functionally stable.
The authors’ preference is the rigid fixation technique
because it is less painful and shortens healing tim e. In
addition, rigid fixation can shorten the IMF tim e. Once
osteosynthesis is done, the IMF is released to check for
norm al occlusion as planned. The wound is then irri-
gated w ith norm al saline, and a final check for hem o-
stasis is done before closure w ith 4–0 silk. A 4- to 5-cm
silastic drain is anchored on each side.
After the cortex of the anterior ramus border has been
removed as described earlier, the authors create several
guide holes in the medulla (Fig. 21.7b) down to the poste-
rior border with a 1.8-mm round bur. Care is taken to avoid
the inferior alveolar nerve and vessels by staying close to
the buccal cortex, especially at the mandibular body and
angle area. Ramus splitting is completed by joining these
guide channels with a 2-mm chisel (Fig. 21.7c). The separa-
tion should be performed gently and precisely, taking care
not to cause unwanted fracture of any segment.
The tooth-bearing segment is referred to as the distal
segment while the segment bearing the condylar head is the
proximal segment. Once the proximal and distal segments
are separated, the mandibular body can move freely. With
the prefabricated occlusal splint wired to the upper teeth,
the free-moving mandibular distal segment can be easily
adapted to the upper teeth and splint. Intermaxillary xation
(IMF) is then performed with the maxillary and mandibular
teeth occluded in this new position. The authors generally
prefer elastic rubber bands over wires for this purpose.
The new m andible position is checked w ith the
m idline draw n preoperatively to ensure facial sym m e-
Fig. 21.7 Sagittal split ramus osteotomy (SSRO). (a)
Mucosal incision line. (b) Osteotomy is done following
the guide holes created in the medulla down to the
posterior border. (c) Ramus splitting and repositioning
to the proper new occlusion.
a
b
c

IV Facial Bone Surgery
276
Intraoral Vertical Ramus Osteotomy (IVRO)
This method is relatively simple and particularly useful
for asymmetric cases requiring mandibular mobilization
(Fig. 21.9). After elevating the lateral periosteum o the
ramus from the sigmoid notch to the inferior border of the
mandible (gonial angle), the osteotomy is made from the
sigmoid notch to the mandibular foramen posteriorly with
an oscillating saw. Great care should be taken near the man-
dibular foramen not to damage the vascular bundle, which
can potentially cause massive bleeding. Occasionally, the
antilingula on the lateral surface can be used as a reference
to approximate the lingula on the medial surface. After
completing the vertical osteotomy, the prepared splint is
used to guide the distal segment to normal occlusion. The
distal segment should be located on the medial surface of
the proximal segment. Osteosynthesis with a miniplate
is not obligatory in this case, and intermaxillary xation
alone w ith or without interosseous w iring normally suf-
ces. This intermaxillary xation is kept for 6 to 8 weeks.
Surgery of the Maxilla
The most w idely performed maxillary orthognathic sur-
gery is the Le Fort I osteotomy with down fracture.12 This
operation is relatively simple, but if not performed cor-
rectly, it can have dire consequences such as severe hemor-
rhage, laryngeal edema, and respiratory failure. Lidocaine
and epinephrine (1:100,000) is injected into the labial
and buccal vestibule including the subperiosteal area. This
hydrodissection will make raising the mucoperiosteal ap
easier, as well as decrease the amount of bleeding dur-
ing the surgery. The midpoint is marked with a 6–0 nylon
High Sagittal Supraforaminal
Osteotomy (HSSO)
High sagittal supraforaminal osteotomy (HSSO), also
referred to as supraforaminal horizontal oblique osteotomy
(SHOO),10 was originally designed by WJ Höltje,11 and it
derived from Schuchardt (Fig. 21.1). HSSO is an esoteric yet
more clinically attractive method than traditional SSRO11
because of its shorter operating time; lesser bleeding
tendency and invasiveness; lower risk of inferior alveolar
nerve injury; and faster recovery.
HSSO begins w ith a m ucosal incision starting at
the lowest point of the ascending ram us and proceed-
ing laterally up the anterior border of the ram us. A
25- to 30-m m incision is usually su cient (Fig. 21.8a).
The periosteum is elevated o the lateral surface of the
ascending ram us up to its posterior border. The authors
use a simple lateral retractor (w idth 20 m m ) to protect
the lateral and posterior surface during the osteotomy.
Medial surface periosteal elevation is done between the
sigm oid notch and the foram ina above the m andibular
foram en. As this area is highly vascularized, it tends to
bleed from the m uscular and nutrient vascular branches.
A 5- to 15-m m narrow tunnel is usually su cient to per-
form the m edial osteotomy. The elevation is continued
until the lateral retractor from the lateral side is encoun-
tered at the posterior border. The osteotomy on the lat-
eral cortical surface is 10 to 15 m m lower than the m edial
osteotomy on the ascending ram us (Fig. 21.8b). After the
m edial and lateral osteotom ies are completed, splitting
is perform ed. Fixation is done using a m axiplate w ith
four screws on each side for osteosynthesis (Fig. 21.8c).
An alternative is to use two four-hole m iniplates w ith
eight screws on each ram us.
Fig. 21.8 High sagittal supraforaminal osteotomy (HSSO). (a) The incision line is 25 to 30 mm long and follows the anterior border of
the ramus. A simple lateral retractor (width 20 mm) is applied to protect the lateral and posterior surface during the osteotomy. (b) The
osteotomy on the lateral cortical surface is ~ 10 to 15 mm lower than the medial osteotomy on the ascending ramus. (c) Osteosynthesis
is performed using a maxiplate with four screws on each plate.
a
b
c

21 Aesthetic Orthognathic Surgery
277
The soft palate at the posterior end can be protected
with a nger during the separation. Next, the pterygoid
plate is separated from the maxilla with a curved pterygoid
osteotome. The operator’s nger should be placed on the
pterygoid hamulus during the osteotomy at the pterygo-
maxillary junction to prevent injury to the maxillary artery
and pterygoid plexus (Fig. 21.10c). Once detachment of
the nasal septum, anterior maxillary sinus wall, maxil-
lary tuberosity, and pterygoid process is completed, the
maxilla is ready to be down-fractured (Fig. 21.10d). This
can be done with Rowe disimpaction forceps or manually.
With the Rowe forceps, the blade with the large curvature
protects the anterior upper teeth and the other, shorter
blade holds the nasal oor. Perform the down-fracture in a
deliberate and atraumatic manner to prevent uncontrolled
fracture lines and bleeding. Once the down-fracture is com -
pleted, the segment is held down with a bone hook while
bony irregularities are smoothed with diamond burs or the
ultrasonic bone cutter. In maxillary setbacks or upward
displacements, the posterior sinus wall should also be
trimmed to create space for the desired posterior or supe-
rior movements. Avoid injuring the descending palatine
artery during bone rongeuring at the posterior sinus wall,
as this can potentially cause a catastrophic hemorrhage.
Once the posterior sinus wall has been prepared, the
maxilla is moved into the new planned position using the
prefabricated splint as a guide. With this new occlusion,
IMF is applied using intraoral elastic bands on the brackets.
Measurements can then be taken of the length of the stitch
at the medial canthus to the bracket of the central incisors
to con rm that the correction as preoperatively planned
has been achieved. Four L-shaped, four-hole miniplates
are used for osteosynthesis. One is placed on each side of
the piriform rim, and one on each of the lateral buttresses
(Fig. 21.10e). A cinch suture is applied at the alar base
before wound closure to prevent splaying of the alar base
(Fig. 21.10f). For closure, the authors start by putting one
stitch on the premarked nylon suture in the midline with
4–0 or 3–0 silk (incisor area). The wound is then closed
starting from the lateral-most edge ( rst molar area) and
working medially. At the midline, a V-Y closure is fashioned
to restore the normal appearance of the upper lip; other-
wise it may look at and elongated. Finally, two passive
silastic drains are inserted, one on each side, and anchored.
Bimaxillary Surgery
Anterior Segmental Osteotomy for
Bimaxillary Protrusion
Bimaxillary protrusion is most prevalent in Southeast and
East Asia. The typical characteristics of bimaxillary protru-
sion are protruded maxilla and mandible, retruded small
chin, acute nasolabial angle with/without open bite, and a
suture for reference later. A mucosal incision is made 5 to 8
mm above the mucogingival junction, from the distal rst
molar of one side to the other. The authors typically use a
thin needle electrocautery for this purpose. Hemostasis is
performed meticulously as the incision is deepened in lay-
ers. At the end, a 5-mm up-cut is done to prevent mucosal
tearing during dissection of the pterygoid process.
Once the bone is reached, periosteal dissection is per-
formed from the piriform aperture (not entered at this point)
to the zygomatic crest. Dissection should be done carefully
to avoid entering the buccal fat pad. The anterior dissection
extends from the anterior nasal spine up to the infraorbital
foramen. Great care should be taken while elevating the nasal
mucosa from the nasal septum, hard palate, and lateral nasal
wall. A nasal mucosal tear (especially at the nasal oor) results
in an annoying hemorrhage that can be a challenge to control.
After lifting the periosteum, the planned osteotomy
lines are drawn on the bone with a pencil. Using a diamond
bur, 5-mm holes are made on the anterior maxillary wall.
The sinus mucosa is then lifted o the anterior maxillary
wall. Using a reciprocating saw, a horizontal transverse
osteotomy is made starting at the lateral wall of the piriform
fossa and ending at the maxillary tuberosity (Fig. 21.10a).
When making the cut over the anterior maxillary sinus
wall, the sinus mucosa can be protected with a exible peri-
osteal elevator. Once this horizontal osteotomy is performed
on both sides, the lower part of the nasal septal cartilage
and vomer is detached from the maxilla and palatine bone
using a nasal septum osteotome (Fig. 21.10b).
Fig. 21.9 Intraoral vertical ramus osteotomy (IVRO). Vertical
ramus osteotomy is useful in case of mandibular asymmetry or
prognathism. The segments are xed with interosseous wiring or
miniplates and screws. The position of the TMJ can be passively
adapted. This method is simple but requires a long period of inter-
maxillary wiring (more than 6 weeks).

IV Facial Bone Surgery
278
the labial side and to the coronal midline of the hard palate
on the palatal surface. Extraction of both upper and lower
rst premolars follows (Fig. 21.11b).
The premolar socket marks the osteotomy line and
the amount of posterior setback of the anterior segment.
The bone spicules at the edges are smoothed to allow for
proper bone contact during osteosynthesis later. Care must
be taken not to injure the canine and second premolar by
keeping the intervening socket wall intact. The osteotomy
lines are marked on this premolar socket with a pencil,
keeping a distance of at least 5 mm posteriorly and 3 to 4
mm inferiorly from the anterior teeth roots, and run par-
allel to the nasal oor. The buccal and palatal bony wall
at the extracted socket is removed primarily with a bone
rongeur. Using a small round bur, the authors usually make
small ports along the planned osteotomy line and in ltrate
epinephrine and lidocaine into the marrow prior to per-
forming the osteotomy. The authors start by deepening a
groove along the planned osteotomy line with a 3.8-mm
round bur (Fig. 21.11c). The diameter of the bur is deter-
mined by the amount of shortening required. Alternatively,
small interincisal angle. Indications for anterior segmental
osteotomy (ASO) for patients with bimaxillary protrusion
include
1. Protrusion of maxillary teeth and bone, causing
signi cant facial deformity
2. Orthodontically untreatable protrusion, such as
ankylosed teeth, root resorption, or immovable/
slow-moving tooth due to thick bone stock
3. Anterior open bite not treatable with orthodontic
treatment alone
4. Unaesthetic small chin with lip excess
First, segmental osteotomy of the maxilla is performed.
On the labial side, the marginal gingival incision runs from
the second premolar of one side to that of the other side.
The palatal marginal gingival incision is shorter, from the
canine to the rst premolar on each side (Fig. 21.11a). This
incision can preserve the vascular supply to the bone since
there are no mucosal incisions. Once the incision is made,
the periosteum is elevated to the anterior nasal spine on
Fig. 21.10 Le Fort I osteotomy. (a) Osteotomy starts at the lateral wall of the piriform fossa and ends at the maxillary tuberosity (red line).
(b) The lower part of the nasal septal cartilage and vomer is detached from the maxilla and palatine bone using an osteotome. (c) The
pterygoid plate is separated from the maxilla with a curved pterygoid osteotome. (d) The maxilla is down-fractured. (e) Four L-shaped,
four-hole miniplates are applied on each side of the piriform rim and lateral buttress. (f) A cinch suture is applied at the alar base before
wound closure to prevent splaying of the alar base.
b
a
c
d
e
f

21 Aesthetic Orthognathic Surgery
279
Double Jaw Surgery
Double jaw surgery is also called two-jaw surgery or bimax-
illary surgery. Double jaw surgeries should be limited to
patients in whom (1) the amount of mandibular setback
required is more than 14 mm (in these cases, mandibular
osteotomy alone is insu cient to achieve normal occlusion,
and will likely have a high relapse or complication rate), (2)
signi cant open bite or serious bimaxillary protrusion in
class III malocclusion is present, or (3) horizontal occlusal
canting cannot be adequately corrected orthodontically.
The maxilla and mandible are osteotomized and mobi-
lized as described previously in the same setting. Opera-
tion begins with a Le Fort I maxillary osteotomy and the
maxilla is down-fractured. Next the maxilla is aligned with
the help of a prefabricated splint and xed with miniplates
and screws. Mandibular osteotomy w ith SSRO or HSSO is
performed next and aligned and xed in a similar man-
ner. The new occlusion is planned preoperatively and two
splints are necessary: One is used as an intermediate splint
after maxillary osteotomy to t the movable maxilla to the
untreated mandible, and the other is for after the mandibu-
lar osteotomy, to be used as the nal splint.

■Postoperative Care
Day surgery is possible after postoperative monitoring for
~ 4 to 5 hours. The next visit is on postoperative day 3, for
removing the silastic drain and dressing the wound. On
postoperative day 4 or 5, IMF is released and two middle
a reciprocating saw can be used. Bleeding from the incisive
foramen during drilling is controlled by bone wax easily.
The maxillary sinus can be encountered as the groove is
deepened. The sinus mucosa is kept intact and lifted o the
bone instead of being cut through.
Once the osteotomy is completed, the segment is mobi-
lized and the preoperatively fabricated splint is used as a
guide to achieve the desired occlusion (Fig. 21.11d). The
canine and second premolar teeth are ligated with wires
on both sides and IMF is done. The occlusion is checked
before osteosynthesis with four-hole, L-shaped miniplates
and screws. After rigid xation is achieved, the splint is
removed and the marginal gingival incision is closed with
interdental sutures.
Segmental osteotomy of the mandible is very similar
to that of the maxilla. A marginal gingival incision is made
from the second premolar of one side to that of the other
side (Fig. 21.11a). Subperiosteal dissection proceeds along
the chin and body of the mandible. The osteotomy line is
marked and the rst premolars are extracted on both sides.
The bone is cut in a similar manner as described perviously
to create the anterior segment (Fig. 21.11c). The splint is
applied next to get the desired alignment and occlusion.
IMF with orthodontic rubber elastics is done, followed by
osteosynthesis with 4-hole straight plates bent for proper
t and adaptation. Interrupted interdental papillary sutures
are used to close the incision and a silastic drain is inserted.
For ASO, the prefabricated occlusion splints are used
purely to guide the planned anterior occlusion and then
removed prior to extubation. Postoperative IMF is not
required, and the patient is allowed to open his or her
mouth immediately.
Fig. 21.11 Anterior segmental osteotomy (ASO). (a) The palatal marginal gingival inci-
sion is made from the canine to the rst premolar on each side of the maxilla and mandible.
(b) Extraction of both upper and lower rst premolars follows. (c) Osteotomy is performed
by burring out a groove along the planned osteotomy line. (d) The segment is mobilized
and a splint fabricated preoperatively is used as a guide to achieve the desired occlusion.
a
b
c
d

IV Facial Bone Surgery
280

■Complications and
Their Management
Common Complications Following
Facial Bone Surgery
Bleeding during SSRO occurs mainly from the bone marrow
of the ramus and body of the mandible. Nutrient arteries
from adjacent soft tissue also contribute to the bleeding.
These are mostly self-limiting and non-life-threatening.
Severe bleeding, however, can result from injury to the infe-
rior alveolar artery during elevation of the periosteum o
the lingual cortex. Hence, the utmost care should always be
taken when dissecting near the lingual cortex, and proper
soft tissue protection with broad elevators should always
be employed to avoid such mishaps. If severe bleeding is
encountered, packing the lingual tunnel with epinephrine-
soaked gauze and applying direct digital pressure over the
mandibular foramen remains the most reliable way to slow
the bleeding. The pressure should be sustained for ~ 5 to 10
minutes. After the bleeding has ceased, the packing is kept
in situ while the other side is prepared. The osteotomies
may proceed as per usual if there is no rebleeding. Surgicel
or brin glue can be applied to the bleeding area after lin-
gual cortical osteotomies.
If massive bleeding results from facial artery injury
during SSRO, the bleeding site should be packed with epi-
nephrine gauze with digital compression. A 2–0 or 3–0
hemostatic suture can be applied over the bleeding area.
During Le Fort I osteotomies, the vessels at risk are the
descending palatine artery, the maxillary artery, and the
pterygoid plexus.13,14 The descending palatine artery in the
retromaxillary region is particularly vulnerable during sepa-
ration of the maxilla from the pterygoid process or down-
fracturing of the maxillary segment because this process is
not visualized directly. Thus, placement of the osteotome at
its inferior aspect by palpation is critical to avoid vessel injury
within the pterygopalatine fossa.14,15 Sometimes delayed
secondary hemorrhage (days 1–2 or 7–9) can arise from the
tuberosity area. Although the amount of bleeding is mod-
erate, it should be managed promptly as it can potentially
develop into airway obstruction. Bleeding from the nasal
oor and sinus mucosa can be controlled spontaneously.
Infection is uncommon following orthognathic surgery;
the reported incidence is less than 1%.16,17 Nonetheless, if
infection occurs, it is usually associated with the mandibu-
lar osteotomy. Following SSRO procedures, massive irriga-
tion to remove bony dust and chips is required.14 Empirical
antibiotics are routinely prescribed for 7 days after surgery. If
localized infection occurs around the screws, then it is recom-
mended that they be removed. Postoperative pain is usually
minimal and is easily controlled with analgesics such as acet-
aminophen. Severe TMJ pain can occur on the third or fourth
postoperative day and may require loosening of the IMF.
ring elastics are used on each side to enable the patient to
start early mobilization of the TMJ with slight mouth open-
ing. On postoperative day 7 or 8, the splint is removed and
the orthodontist begins postoperative orthodontic treat-
ment. The sutures are usually removed on postoperative
day 10.
Antibiotics and analgesics are prescribed in liquid
form. The patient is advised to always carry around a pair
of small scissors to cut o the rubber elastics in case of an
emergency.

■Key Technical Points
1. Prior to elevating the lingual periosteum of the
ascending ramus, in ltration of epinephrine and
lidocaine is helpful to avoid accidental rupture of
nutrient vessels emerging from the bony foramen.
2. During periosteal elevation for lingual cortex
osteotomy, keep the dissection area narrow to avoid
damage to the vessel and nerve from the mandibular
foramen.
3. For accurate ramus splitting, create several guide
holes in the medulla, down to the posterior border
w ith a 1.8-mm round bur. Ramus splitting is
completed by joining these guide channels with a
2-mm chisel.
4. Rigid xation after precise reduction is key to
shorten IMF and bone healing time, and painless
healing.
5. The operator’s nger should be placed on the
pterygoid hamulus during the osteotomy at the
pterygomaxillary junction to prevent injury to the
maxillary artery and pterygoid plexus.
6. After maxillary bone surgery, a cinch suture is
applied at the alar base before wound closure to
prevent splaying of the alar base.
7. During ASO, care should be taken not to injure
the canine and second premolar by keeping the
intervening socket wall intact after extraction of the
upper rst premolars. The bone spicules at the edges
are smoothed to allow proper bony contact during
osteosynthesis.
8. The osteotomy lines should be kept at least 5 mm
away from the anterior teeth roots so as not to
disrupt the vascular supply to the tooth.

21 Aesthetic Orthognathic Surgery
281
osteotom ies hinder the segm ents from m oving freely to
the new planned position. As a result, the segm ents are
instead brought into occlusion by force, w hich inevitably
leads to relapse. Incomplete osteotomy m ost com m only
occurs at the posterior ram us of the m andible, w hile the
m axillary tuberosity and pterygoid plate are the m ost
com m on sites in the m axilla.
Unfavorable Osteotomies
During maxillary surgery, uncontrolled fracturing may
occur when a down-fracture is attempted despite incom -
plete osteotomy. To identify the resistance, the maxillary
down-fracture should be performed with digital pressure
only, and Rowe disimpaction forceps should be used only
for mobilization after separation. Unfavorable fracture sites
during mandibular surgery are the condylar neck, lingual
plate, and buccal plate, and the incidence rate ranges from
3 to 23%.20,21 If inadvertent fracture occurs during surgery,
prompt management for the fracture should be under-
taken, depending on its pattern and on whether the distal
segment advances or sets back. A prolonged postoperative
maxillary-mandibular xation is also helpful.14
Condylar Resorption
Condylar resorption is a late complication that usually
occurs 7 to 12 months after the surgery.14 The etiology is
not known yet, but caution should be paid to patients hav-
ing class II malocclusion, small or abnormal shape of the
condyle.14,22 Progressive condyle resorption may lead to
open bite and loss of posterior facial height. The surgeon
must wait at least 6 months until the resorption is com -
pleted. There is no e cient treatment, but in cases of severe
resorption, total joint reconstruction may be required.
Partial Necrosis of Bone Segment and
Mucosa
Vascular ischemia and tissue necrosis are caused by unfa-
vorable soft tissue incision, excessive stretching of the
palatal soft tissue pedicle, minute segmentalization of the
maxilla, extensive hypotension, severance of feeding ves-
sels, and general conditions that induce transient vascular
ischemia. Usually, vascular compromise is transient but it
can result in devitalization of the teeth, periodontal defects,
and segmental bone loss. For prevention, excessive perios-
teal stripping should be avoided and osteotomy should be
made 5 to 6 mm distant from teeth roots.23 When tissue
necrosis occurs, use of recombinant bone morphogenetic
protein 2 (r-BMP2) and platelet-rich plasma (PRP) weekly
for a month can be attempted. In some cases, endodontic
treatment is needed (Fig. 21.12).
Complications Speci c to Maxillary
and Mandibular Orthognathic Surgery
Nerve Injury
The infraorbital nerve can be damaged during maxillary
surgeries and cause numbness of the upper lip with or
without involvement of the maxillary teeth, gingiva, and
alveolar bone. Generally, sensory loss in the infraorbital
nerve distribution is temporary and resolves gradually over
a 12- to 18-month period.14 Rarely, it develops into infraor-
bital neuralgia in severe cases.
In contrast to maxillary orthognathic surgery, man-
dibular surgery has a higher rate of temporary (60–70%)
or permanent (20–30%) nerve injury.18,19 Presumably, the
injury is sustained during osteotomy of the lower lateral
end of the body of the mandible, or during mandibular
splitting since it often requires cutting near the nerve, and
sometimes even crossing the mandibular canal. This is one
of the reasons the authors prefer HSSO. The low incidence
of nerve injury can be attributed to the fact that the areas
of osteotomy and splitting are far away from the nerve dur-
ing HSSO. Another danger site is near the molar or premo-
lar areas during the lateral cortical osteotomy, where the
nerve can course laterally near the osteotomy lines. The
patient who experiences such a violation will complain of
numbness over the corner of the mouth.
Functional Relapse
One of the m ain factors increasing the risk of relapse
after orthognathic surgery is an occlusal discrepancy
that induces the m andible to m ove in an abnorm al direc-
tion. This occurs usually w ithin a m onth. Therefore, it is
advisable to send the patient to an orthodontist 5 to 7
days after surgery. Another concern is the TMJ factor. An
unstable TMJ w ill result in an unstable occlusion, and this
eventually leads to relapse and recurrence of m alocclu-
sion after surgery. The authors prefer to get the TMJ in a
good condyle-fossa t before aligning the distal segm ent.
Abnorm al m uscular traction also can lead to functional
relapse. Soft tissue has a tendency to return to its pre-
operative position after surgery. For example, if the pos-
terior facial height is longer than before, the m uscles are
stretched eccentrically and tend to recoil back to their old
positions. This causes m andibular instability, w ith the
m andible m oving in a rotatory direction, or back to its
previous position. The pterygom asseteric m uscle is sus-
pected to be a m ajor contributor to this phenom enon. As
a result, the patient w ill have a relapse of an open bite or
class III m alocclusion. Other than the pterygom asseteric
m uscles, the tongue, lips, cheek, and suprahyoid m uscles
are also involved in such a relapse. One way to counter-
act this is to use a rigid xation. Technically, incomplete

IV Facial Bone Surgery
282
had long face w ith a highly concave facial pro le and
a protrusive chin that he found aesthetically unpleas-
ing. He was classi ed as class III m alocclusion. After a
9-m onth preoperative orthodontic treatm ent, HSSO and
genioplasty were perform ed. Reduction in the am ount of
the genioplasty was 12 m m , and the am ount of setback
was 13.4 m m . Over-correction was m andatory to prevent
relapse (Fig. 21.14).

■Case Studies
Case 1: Mandibular Prognathism
with Long Face
A young m ale patient visited for habitual luxation of
TMJ accompanying chew ing di culty (Fig. 21.13). He
Fig. 21.12 Partial necrosis of bone segment. (a) The X-ray shows that partial necrosis of
the bone segment developed 10 days after surgery. (b) The anterior maxillary bone was
recovered, but root resorption remained.
Fig. 21.13 Case 1. Mandibular prognathism with long face. (a,b) Preoperative photo-
graphs. (c,d) Preoperative cephalometry and panoramic view.
a
b
a
b
c
d