Orthognathic Surgery

641
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
arch-width constriction that also requires correction.
Although this categorization of primary mandibular defi­
ciency may appear arbitrary, it focuses on a distinct sub­
group of patients who routinely present for clinical
assessment and treatment.
Functional Aspects
• Articulation errors during speech and swallowing diffi­
culties that result from the Class II malocclusion are
expected (see Chapter 8).
• Difficulties with chewing and with lateral and protrusive
mandibular movements as a result of the Class II maloc­
clusion are also expected.
• Upper airway obstruction during sleep often exists as a
result of the retropositioned tongue. Obstructive sleep
apnea should be ruled out (see Chapter 26).
• Detrimental long-term effects on the dentition and the
periodontium as a result of the crowding of the man­
dibular teeth in limited alveolar housing or from previ­
ous camouflage orthodontic treatments are often seen
(see Chapters 5 and 6).
• A higher incidence of temporomandibular disorders that
result from mandibular deficiency Class II malocclusion
have been reported (see Chapters 9 and 36).
Clinical Characteristics
• The lower lip is curled and everted, and it is often wedged
behind the incisors with an accentuated labiomental
fold. The shorter the lower anterior facial height, the
greater the tendency for an accentuated labiomental fold.
• The gonial angles of the mandible tend to be relatively
square. The shorter the face and the deeper the bite, the
more acute the angles.
• There is a retruded and weak chin with a convex profile.
• There is a deficient mandible with the illusion of a
large nose.
• There is a short chin-to-neck length and an obtuse angle,
often with a double chin (even in a thin individual).
• The upper lip appears short, curled, and protrusive.
Dental Findings
• There are varied degrees of increased overjet with a Class
II molar and canine relationship.
• The crowding of the teeth within the lower arch (i.e., the
smaller the mandible, the greater the crowding) needs to
be evaluated, and so does lower incisor flaring. Mandibu­
lar dental compensations often mask the true skeletal
discrepancy.
• There are varied degrees of dental compensation in the
upper jaw with either procumbency (i.e., “buck teeth”)
or maxillary incisors that are retroclined.
• The anterior deep bite (i.e., excessive overbite) may
involve impingement of the anterior maxillary palatal
tissues by the mandibular incisors.
• There is an excessive curve of Spee in the mandible (i.e.,
the deeper the anterior bite, the greater the excess curve).
• A reduced or negative curve of Spee is found in the
maxillary arch.
• Dental crowding may also be seen in the maxilla
(i.e., the more constricted the maxilla, the greater the
crowding).
• Excessive wear facets, cusp fractures, and significant res­
torations in the posterior dentition are frequent findings
in adults.
• Accelerated loss of the periodontium associated with the
maxillary incisors (due to traumatic occlusion or previ­
ous orthodontics); the maxillary molars (due to arch
constriction or previous orthodontics); and the man­
dibular incisors (due to supraeruption and anterior
flaring from previous orthodontics) may be seen in
adults.
Radiographic Findings
• Horizontal retrusion is measurable at the B-point of the
mandible.
• The A-point–nasion–B-point angle is generally increased
as a result of the retrusive lower jaw.
• Excessive procumbency of the mandibular incisors is
frequently measurable.
• A vertically short and retrusive chin is generally
measurable.
• The maxillary incisors are often procumbent, but they
may be retropositioned as a result of previous extractions
and camouflage orthodontics.
Treatment Indications and Objectives
The individual’s immediate aesthetic concerns often center
on 1) unfavorable lower-lip contours (e.g., a curled and
everted lower lip with an accentuated labiomental fold) 2)
a lack of prominence of the chin (e.g., a weak profile) and
3) an unattractive neck (e.g., a soft-tissue double-chin ten­
dency).27,38,39,42,48,47,50,59 Functional issues are also to be
expected. For example, when the anterior bite is “deep,” it
will cause irritation of the gingival tissues of the palate just
behind the maxillary incisors. Partial obstruction of the
upper airway as a result of a retropositioned tongue is also
common (i.e., heavy snoring, restless sleep, daytime fatigue,
and documented or undiagnosed sleep apnea; see Chapter
26).11,62 Complaints of an uncomfortable “dual” bite,
chewing difficulties, masticatory muscle discomfort, and
audible speech articulation errors are frequent. The indi­
vidual with a Class II deep bite may have a greater tendency
toward clicking (i.e., anterior disc displacement) in each
temporomandibular joint.25,51 Interestingly, there is little
scientific evidence to support the notion that the signs of
clicking will into more significant temporomandibular joint
pathology (see Chapter 9).

642 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
dance with this rationale, mixed dentition growth modifica­
tion treatment frequently incorporates the following steps:
1. The alignment of the upper incisors (i.e., the correction
of lingual tipping with a Class II, Division 2 maloc­
clusion) to prevent any interference with the forward
movement of the mandible.
2. Attempts to impede the biologic programmed forward
growth of the maxilla and to facilitate the forward
growth of the mandible. Extraoral (posterior vectored)
compressive forces are typically applied to the maxilla
through a headgear device.
3. Attempts to stimulate the mandibular posterior teeth to
hypererupt while preventing the incisors from doing so.
During this process, it is hoped that the deep overbite
will improve. An intra-oral functional appliance is
often designed to facilitate these events.
Orthodontic Camouflage Approach
When the orthodontist proceeds with growth modification
maneuvers and a less than favorable biologic response is
realized, it is apparently tempting to proceed with a cam­
ouflage (dental compensation) approach (Figs. 19-1 through
19-5).34,35,37,36,42 This would be carried out to “neutralize”
the occlusion rather than to position the teeth solidly into
the alveolar process in combination with orthognathic
surgery. Current evidence-based medical standards recom­
mend that the treating orthodontist have a “timeout” (i.e.,
a sit-down discussion and reassessment with the parents and
the patient) that includes a review of the records (e.g.,
photos, models, radiographs) and a discussion of the bio­
logic effects on the airway, the facial aesthetics, the occlusal
stability, and the periodontium that may result from the
various treatment options. A referral to an experienced
orthognathic surgeon for the discussion of possible future
surgical aspects is highly recommended.
An orthodontic camouflage approach for the individual
with mandibular deficiency may take the form of maxillary
premolar extractions so that the upper incisors can be
retracted. This is generally combined with the flaring of the
mandibular incisors. When this is carried out in the indi­
vidual with a mandibular deficiency, the short-term objec­
tive of a neutralized occlusion may be achieved, but the
following are potential sequelae: 1) unfavorable long-term
facial aging 2) the risk for obstructive sleep apnea later in
life 3) long-term periodontal deterioration 4) lower anterior
crowding with recurrent malocclusion and 5) an inconsis­
tent occlusion (i.e., a dual bite) (see Figs. 19-1 through
19-5). The orthodontist may feel favorable toward a cam­
ouflage approach on the basis of the belief that the patient
can always have a “chin implant” to improve his or her facial
aesthetics. Unfortunately, this approach will rarely achieve
a pleasing aesthetic outcome. A chin implant tends to result
in 1) an accentuated labiomental fold 2) an overly promi­
nent pogonion and 3) a residual obtuse neck–jaw angle
When the mandible is deficient, with significant overjet,
and when the anterior facial height is short, the lower lip
tends to “get caught” behind the maxillary incisors. During
growth, if the lower lip stays behind the upper teeth, then
the upper teeth will adapt by tipping forward, thus creating
a Class II, Division 1 malocclusion with varied degrees of
maxillary incisor spacing. When the mandibular deficiency
and the protrusive lower incisors are combined with pro­
cumbent maxillary incisors, the individual tends to be con­
cerned with both the lack of chin prominence and the
protruding maxillary anterior teeth (i.e., a toothy smile).
Alternatively, if the lower lip remains in front of the maxil­
lary incisors, there is an adaptive tendency for the maxillary
incisors to tip lingually (i.e. Class II, Division 2).
The Role of Growth Modification in
the Preadolescent Child
When the preadolescent child with mandibular deficiency
is identified, a growth modification approach to treatment
is frequently considered by the evaluating orthodontist.13,33,32
Cozza and colleagues completed a systematic review of the
literature to assess the efficacy of functional appliance use
for enhancing mandibular growth in subjects with Class II
malocclusions.14 With the use of the Medline database, the
survey covered the period from January 1966 to January
2005. A review of 704 articles confirmed only 22 that quali­
fied for the final analysis. Of these 22 articles, only four
randomized clinical trials were retrieved and found to be
worthy of inclusion. Interestingly, none of these four trials
reported a clinically significant change in mandibular length
to be induced by functional appliances in the patients with
Class II deformities. According to Proffit, the only concrete
indications for the treatment of the preadolescent mixed
dentition child with a mandibular deficiency who presents
without an anterior open bite are the following44:
• Significant trauma to the palatal tissue (i.e., the lower
incisors are injuring the palatal mucosa) or other indi­
cations of potential irreversible tissue damage
• Special concerns about the effects of the condition on
the child’s psychological well-being and the strong
belief that the recommended treatment will alter this
in a positive way
• Skeletal maturation that is well ahead of dental devel­
opment so that the adolescent growth spurt occurs
before the mixed dentition ends
Despite the review by Cozza and colleagues and Proffit’s
stated limited indications for early mixed dentition treat­
ment in the child with a mandibular deficiency, a growth
modification approach is often carried out by the evaluating
orthodontist. The goals are frequently stated to be the
restraining of forward maxillary growth while encouraging
the mandible to grow downward and forward. In accor­

643
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
with those subjects with a normal Class I occlusion.55 Each
subject was followed from the prepubertal stage through the
postpubertal stage of development. The study provides evi­
dence of a similar growth pattern in both Class II and Class
I subjects. The absolute amount of mandibular lengthening
at the pubertal peak was significantly smaller in the Class
II subjects than in those with normal occlusion. A signifi­
cant deficiency was measured in overall mandibular length
(i.e., Condyle-Gonion [Co-Gn]) in the Class II malocclu­
sion subjects at the completion of growth. Interestingly, the
(Fig. 19-4). Furthermore, it does nothing for any baseline
masticatory and airway dysfunction (see Chapter 37).
Definitive Reconstruction
Timing of Orthognathic Surgery
Stahl and colleagues carried out a longitudinal study to
compare the biologic jaw growth changes of untreated sub­
jects with Class II, Division 1 malocclusions as compared
• Figure 19-1  A 20-year-old man with a primary mandibular deficiency growth pattern requested a surgical consultation for a weak chin.
During his early teenage years, the patient underwent growth modification in an attempt to stimulate the forward projection of the mandible.
This was followed by an orthodontic camouflage approach that included maxillary first bicuspid extractions to retract the anterior teeth. In
addition, the mandibular anterior dentition was flared forward. His history was significant for heavy snoring, restless sleeping, and a degree
of daytime fatigue, all of which are suggestive of obstructive sleep apnea. Examination confirmed a retrognathic mandible with a molar Class
II deep-bite malocclusion. The mandibular incisors were crowded and procumbent. The family had hoped that a chin implant would be
effective to manage the aesthetic effects. A sleep study was recommended, and an orthognathic approach with redo orthodontic treatment
including lower bicuspid extractions was suggested as the preferred method to improve the airway, to achieve long-term dental health, and
to enhance facial aesthetics. A, Frontal facial and occlusal views. B, Profile facial view and lateral cephalometric radiograph.
Or
O thth
r ogn
g atatathicici Su
Su
Su
Surg
r ery
ry
ry
ry; J.C.
C.
C.
C Pos
os
os
os
os
os
os
os
osnicicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatata hicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
r ; J.C.
C. Pos
os
os
os
o nicicicicick
B

644 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
A review of available research data and clinical reports
indicated that, when orthognathic surgery was undertaken
in the patient with a mandibular deficiency as early as the
completion of the adolescent growth spurt, further signifi­
cant forward growth of the mandible almost never
occurred.31,55 Further horizontal growth of the maxilla at
this age is also not expected. In theory, limited vertical
growth of both the mandible and maxilla may continue;
however, if it does, it tends to be proportionate. Proceeding
with definitive orthognathic surgery in the patient with a
authors’ findings show that a Class II dentofacial dishar­
mony does not have a tendency to self-correct with growth.
There are numerous reports in the literature of surgeons
carrying out successful orthognathic corrections in patients
with mandibular deficiencies who are between the ages of
13 and 15 years. This is before the age at which growth
maturity is typically considered to be complete. Interest­
ingly, after the patient with a mandibular deficiency has
undergone successful surgical correction, there are no
reports late mandibular catch up growth.5,20,23,29,45,52,61
• Figure 19-2  A 21-year-old woman with a primary mandibular deficiency growth pattern requested a surgical consultation
for a weak chin. During her early teenage years, the patient underwent growth modification in an attempt to stimulate the
forward projection of the mandible. This was followed by an orthodontic camouflage approach. The mandibular anterior denti­
tion was flared forward. Her history was significant for restless sleeping and a degree of daytime fatigue, which are suggestive
of obstructive sleep apnea. Examination confirmed a retrognathic mandible with a Class II malocclusion. The mandibular inci­
sors were crowded and procumbent. The family had hoped that a chin implant would be effective to manage the aesthetic
effects. A sleep study confirmed obstructive sleep apnea (respiratory disturbance index = 18/hour). An orthognathic approach
with redo orthodontic treatment including lower bicuspid extractions was recommended as the preferred method to improve
the airway, to achieve long-term dental health, and to enhance facial aesthetics. A, Frontal facial and occlusal views. B, Profile
facial view and lateral cephalometric radiograph.
Or
Or
Or
Orthththththth
r ogn
gn
gn
gn
gn
g atatatatatatatatatatatata hicicicicicic Su
Surg
r ery
ry; J.C.
C.
C.
C.
C.
C.
C Pos
os
o nick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatathicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C Pos
os
os
os
o nicicicick
B

645
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
greater the chance of labial bone loss and gingival recession.
There should be a healthy band of attached gingiva at
the beginning of treatment and flaring of the incisors is
to be avoided. This is a frequent concern in borderline
crowding cases, when the final decision is made to not
extract and then further labial tipping of the incisors
occurs.
Even after successful gingival grafting, if further incisor
flaring is allowed to occur in the presence of deficient labial
bone, negative periodontal sequelae are to be expected. For
patients with borderline crowding, if the incisor crowns are
mandibular deficiency as early as the age of 13 or 14 years—
but only after the eruption and orthodontic alignment of
the teeth—is generally safe from a growth perspective.
Periodontal Considerations before
Orthodontic Treatment
The position of the mandibular incisors in the alveolar
housing has important periodontal consequences (see
Chapter 6). In the retrognathic patient, the more the man­
dibular incisors are orthodontically tipped forward, the
• Figure 19-3  A 20-year-old man with a primary mandibular deficiency growth pattern requested a surgical consultation for
a weak chin. During his the early teenage years, the patient underwent growth modification in an attempt to stimulate the
forward projection of the mandible. This was followed by an orthodontic camouflage approach. The mandibular anterior denti­
tion was flared forward. The patient’s history was significant for heavy snoring, restless sleeping, and a degree of daytime
fatigue, all of which are suggestive of obstructive sleep apnea. Examination confirmed a retrognathic mandible with clockwise
rotation of the maxillomandibular complex. The mandibular incisors were crowded and procumbent. He had hoped that a chin
implant would be effective to manage the aesthetic effects. An orthognathic approach with redo orthodontic treatment includ­
ing lower bicuspid extractions was recommended as the preferred method to improve the airway, to achieve long-term dental
health, and to enhance facial aesthetics. A, Frontal facial and occlusal views. B, Profile facial view and lateral cephalometric
radiograph.
Or
Or
Or
O ththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gnatatatatatatathicicicicic Su
Su
Sur
u g
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C Pos
o nicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatathicicicicicicici Su
Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C Pos
os
o nicicick
B

646 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
treatment approach from the outset. It makes no sense for
the orthodontist to tell the patient that he or she will first
try to avoid surgery. The orthodontic objectives are dia­
metrically opposite, depending on plans for either full cor­
rection (i.e., surgery and orthodontics) or camouflage (i.e.,
orthodontics alone). When a definitive correction is planned
for the individual with mandibular deficiency, lower extrac­
tions to uncrowd the arch should always be considered. The
need for maxillary extractions is not typical. The labial
morphologically large, the judicious use of interproximal
reduction may create the needed space to uncrowd the arch
and to simultaneously upright the teeth (see Chapter 17).
Orthodontic Preparation for
Orthognathic Surgery
The clinicians (i.e., the orthodontist and surgeon), the
patient, and the patient’s family should agree about the
• Figure 19-4  A 29-year-old women arrived to discuss chin aesthetics. During the mixed dentition,
she was recognized as having mandibular deficiency and a constricted maxillary arch width. At that
time, she underwent growth modification techniques that included headgear. She also underwent rapid
palatal expansion followed by compensatory orthodontic mechanics to neutralize the occlusion, but this
also involved proclination of the incisors. A retrusive profile and a dual bite remained. The patient had
recently undergone the placement of a chin implant without fixation. Aesthetic modification of the anterior
maxillary dentition was also completed. The patient was displeased with the cosmetic results of a
deepened labiomental fold, a mobile chin implant, and a “button” appearance during lip closure. There
is a dual bite with Class II malocclusion when the teeth are in centric relation. A, Oblique and frontal
facial views. B, Profile facial view and lateral cephalometric radiograph 6 months after chin implant
placement.
Or
Or
Or
Or
Or
O ththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gnatatatatatatatatatatatathicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry; J.C.
C.
C Pos
osnicicicick
Or
Or
Or
Or
Orththththththththththtr ogn
gn
g atatathicicic Su
Su
Surg
r ery
ry
ry; J.C.
C.
C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
osnicicicicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O ththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatathicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Sur
u g
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C Pos
os
os
os
osnicicicicicicick
B
Chin implant
in place

647
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
The orthodontic leveling of an excessive curve of Spee in
the lower arch is accomplished through a combination
of the intrusion of the incisors and the extrusion of the
mid-arch posterior teeth. With an excessive curve of Spee,
premolar extrusion gives the major effect with only a small
amount of incisor intrusion to be expected. This is initiated
before surgery, but it is most efficiently fully accomplished
after the mandible has been surgically repositioned (i.e.,
forward and down). Alternatively, if extensive intrusion of
the anterior teeth is desired to correct the deep curve, this
region of the mandibular incisors should be assessed for the
need for gingival augmentation before the initiation of
treatment.
For the patient with mandibular deficiency who has
agreed to a combined treatment approach, an important
orthodontic objective is to place the incisors more com­
pletely within the alveolus. Incisor placement will deter­
mine the eventual horizontal and vertical positioning of the
mandible in relation to the maxilla as well as the long-term
periodontal health.
• Figure 19-5  A 43-year-old woman arrived to discuss the aesthetics of her weak chin and premature facial aging. During
her late mixed dentition, she was recognized as having mandibular deficiency with a Class II malocclusion. At that time, she
underwent growth modification techniques followed by compensatory orthodontic mechanics. This included upper first bicus­
pid extractions, the retraction of the anterior maxillary teeth, and the proclination of the mandibular incisors, all in an attempt
to neutralize the occlusion. A retrusive profile and a dual bite remained. The weak profile of her adolescence had progressed
into premature facial aging. She also had a lifelong history of obstructed nasal breathing, restless sleeping, and excessive
daytime fatigue, all of which are suggestive of obstructive sleep apnea. An orthognathic approach with redo orthodontic treat­
ment including lower bicuspid extractions was recommended as the preferred method to improve the airway, to achieve
long-term dental health, and to enhance facial aesthetics. A, Frontal facial and occlusal views. B, Profile facial view and lateral
cephalometric radiograph.
Or
Or
Or
Or
Or
Orthththththth
r ogn
gn
gn
gn
gn
gn
gn
gnatathicicicicicicic Su
Su
Su
Su
Surg
r ery
ry
ry
ry; J.C.
C.
C.
C.
C.
C Pos
os
os
os
osnicicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O thththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gnatatatatatatatatatatatatatatathicicicicicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C.
C Pos
os
o nicicicicick
B

648 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
of the bicuspid extraction space to be closed
postoperatively.
• Passive surgical arch wires to be used for stabilization
during surgery should be full-dimensional and
rectangular.
• With effective plate and screw fixation at each
osteotomy site, continuous intermaxillary fixation
after surgery is not warranted. Nevertheless, the
orthodontic placement of stable hooks throughout
the arch wires is useful both at the time of surgery
and to accomplish supportive vectored elastics
postoperatively.
Immediate Presurgical Planning
The immediate presurgical planning takes into account col­
laborative clinical efforts between the orthodontist, the
surgeon, the patient, and the patient’s family that will have
been ongoing since the initial consultation visits. Depend­
ing on the condition of the dentition and its supporting
structures, the restorative dentist and the periodontist may
also have been intricately involved.
Patient-specific medical and dental records are reviewed,
which include (but are not limited to) the following: radio­
graphs (e.g. computed tomography scans; panoramic,
lateral, and posterior anterior cephalometric and periapical
scans); photographs (facial and occlusal); and dental models.
Immediate presurgical records (i.e., within 2 to 6 weeks
of surgery) will most importantly include facial measure­
ments taken during the direct visual examination; alginate
impressions of the maxilla and mandible; an accurate centric
relation bite; and an accurate face-bow registration.
First, broad-stroke decisions are made regarding pre­
ferred vector changes for each jaw; only then are the precise
millimeter distances and angular changes that are required
in each jaw to achieve the desired result determined (see
Chapter 12).3,4,17,42 Analytic model planning is carried out
on the articulated dental casts with use of the Erickson
Model Table. Splints are constructed to assist with the
achievement of the precise occlusion and the preferred facial
aesthetics in the operating room (see Chapter 13).
During surgical planning for the individual with a
primary mandibular deficiency growth pattern, it is known
that bilateral sagittal split ramus osteotomies with advance­
ment into a corrected overbite and overjet position will be
required (Figs. 19-6 through 19-9).6,21 An important con­
sideration is whether or not surgical repositioning of the
upper jaw (i.e., Le Fort I osteotomy) will also be useful to
correct arch-width discrepancies; to further adjust the hori­
zontal and vertical position of the maxilla; and to alter the
maxillary plane (i.e., pitch orientation) and cant (i.e., roll
orientation) (Figs. 19-10 through 19-15).3,4,15,18,41,40,46,49,60
An assessment of the baseline chin morphology is also
important. Anticipating the location of the pogonion
after jaw repositioning and considering the advantage
of an osseous genioplasty to achieve an enhanced horizontal
should be done before the mandibular advancement surgery.
The correction of a deep curve of Spee via incisor intrusion
will result in less clockwise rotation of the mandible in
association with surgical advancement. This can be lever­
aged for enhanced profile aesthetics.
The mechanics of the orthodontic leveling of the curve
of Spee will generally result in the lengthening of the arch.
The arch expansion primarily occurs at the incisors (i.e.,
labial flaring) and, to a lesser degree, at the molars. Space is
required for both leveling and for aligning. For this reason,
pre-alignment extractions to create space will be required if
the severity of the curve of Spee is significant and if the
available alveolar bone is limited. With a combination of
incisor crowding and a deep curve of Spee, extraction
therapy is always preferred. If the upper incisors are
extremely flared, maxillary premolar extraction to gain
space for retraction is also preferred; however, this is rarely
the case.
When the deficient mandible is surgically advanced
and vertically lengthened to achieve a more ideal overbite
and overjet, the relative widening of the mandibular
arch in the molar region occurs. Maxillary arch expansion
may then be required to correct posterior crossbites. If
more than several millimeters is required, then simultane­
ous surgical arch expansion of the maxilla through segmen­
tal Le Fort I osteotomy is the preferred approach (see
Chapter 17).
Key aspects of presurgical orthodontics in the individual
with mandibular deficiency include the following:
• Recognizing the need for extractions in the mandible
and incorporating this information into the treatment
plan from the beginning
• Recognizing the need for the surgical expansion of the
upper arch (consider incorporating Le Fort I segmen­
tal osteotomies to widen the arch into the treatment
plan from the beginning; see Chapter 17)
• Aligning the teeth independently within each arch
with the objective of a compatible postsurgical
occlusion
• Establishing the preferred sagittal and vertical posi­
tions of the incisors in the alveolar bone so that
the jaw reconstruction that follows will result in
enhanced facial aesthetics and improved head and
neck function.
Additional orthodontic considerations for the individual
with mandibular deficiency include the following:
• To manage an excessive curve of Spee in the lower
arch, a majority of the leveling will be done after jaw
surgery via the extrusion of the premolars.
• If the mandibular arch is fully leveled before surgery,
then the bicuspid extraction spaces should also be
closed before surgery.
• If a degree of lower arch leveling is to be accomplished
after jaw surgery, then it is desirable to leave some
Text continued on p. 682

649
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
A
B
• Figure 19-6  A 15-year-old boy with mandibular deficiency and microgenia underwent a combined orthodontic and surgical approach. The
procedures included bilateral sagittal split ramus osteotomies (horizontal advancement) and an osseous genioplasty (horizontal advancement). One
year later, he underwent a septorhinoplasty procedure to open the airway and to enhance nasal aesthetics. He is shown before and 5 years after
reconstruction. A, Frontal view in repose before and 5 years after reconstruction. B, Frontal views with smile before and 5 years after
reconstruction.
Continued

650 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
C, Oblique facial views before and 5 years after reconstruction. D, Profile views before and 5 years after reconstruction.
• Figure 19-6, cont’d

651
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
F
7 mm mandibular
advancement
G
Prior to surgery (centric occlusion)
After treatment
E
E, Occlusal views with orthodontics in progress (centric occlusal) and 5 years after treatment. F, Articulated
dental casts before (centric relation) and after model planning. G, Lateral cephalometric radiographs before and after
reconstruction.
• Figure 19-6, cont’d

652 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
C
Or
Or
Or
Or
Orththththththththththththththth
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Or
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Orthththththththththththththththththththththththth
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u g
r ery
ry
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ry
ry
ry; J.C.
C.
C.
C Pos
os
os
os
o nicicicick
A
B
• Figure 19-7  A 15-year-old girl with
mandibular deficiency and microgenia
underwent a combined orthodontic
and surgical approach. The surgery
included bilateral sagittal split ramus
osteotomies (horizontal advancement)
and an osseous genioplasty (horizontal
advancement). A, Frontal view in
repose before and after reconstruction.
B, Oblique facial views before and after
reconstruction. C, Profile views before
and after reconstruction.

653
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
E
F
Prior to treatment
After treatment
D
D, Occlusal views before and after the completion of treatment. E, Articulated dental casts that indicate
analytic model planning. F, Lateral cephalometric radiographs before and after treatment.
• Figure 19-7, cont’d

Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
A
B
• Figure 19-8  A woman in her late 20s was referred by an orthodontist for surgical evaluation. During her high school years, the patient underwent
maxillary first bicuspid extractions with orthodontic retraction to neutralize the occlusion in the presence of mandibular deficiency. She now hoped
to improve her profile aesthetics and to achieve long-term dental health. The patient agreed to an ortho­dontic and surgical approach. Orthodontic
(dental) decompensation required opening the maxillary bicuspid extraction spaces for dental implants and crowns. The mandibular arch was also
decompensated. The patient then underwent surgery that included bilateral sagittal split ramus osteotomies (horizontal advancement); osseous
genioplasty (horizontal advancement); and an anterior approach to the soft tissues of the neck (cervical flap elevation, neck defatting, and vertical
platysma muscle plication). A, Frontal views in response before and after reconstruction. B, Frontal views with smile before and after
reconstruction.

655
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
Continued
C, Oblique facial views before and after reconstruction. D, Profile views before and after reconstruction.
• Figure 19-8, cont’d

656 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Prior to retreatment with upper bicuspid extractions as a teenager
Pre surgery with re-opening of upper bicuspid spaces for implants
After treatment with maxillary bicuspid
Implants in place
E
E, Occlusal views before retreatment, with orthodontic decompression in progress, and then after
treatment.
• Figure 19-8, cont’d

657
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
F
G
F, Articulated dental casts indicating analytic model planning. G, Lateral cephalometric radiographs before and after
reconstruction.
• Figure 19-8, cont’d

658 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
©Elsevier Inc.
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O thththththththththththththththththththth
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Sur
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ry; J.C.
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©Elsevier Inc.
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©Elsevier Inc.
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©Elsevier Inc.
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©Elsevier Inc.
Or
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C.
C.
C.
C.
C.
C.
C.
C Pos
os
os
os
o nicicicicick
A
B
C
• Figure 19-9  A woman in her late 20s was
referred by an orthodontist for surgical evalua­
tion. During her teenage years, she underwent
camouflage orthodontics to neutralize the
occlusion, including maxillary first bicuspid
extractions with space closure. She arrived for
evaluation to improve the occlusion and to
achieve enhanced profile aesthetics. She
agreed to an orthodontic and surgical approach.
Ortho­dontic (dental) decompensation required
the proclination of the maxillary anterior denti­
tion and mandibular first bicuspid extractions
with the retraction of the anterior dentition. This
was followed by surgery that included bilateral
sagittal split osteotomies of the mandible (hori­
zontal advancement); osseous genioplasty
(horizontal advancement); and an anterior
approach to the soft tissues of the neck (cervi­
cal flap elevation and neck defatting). A, Frontal
views in repose before and after reconstruction.
B, Oblique facial views before and after recon­
struction. C, Profile views before and after
reconstruction.

659
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Continued
Upper bicuspids removed years earlier. Now undergoing retreatment with mandibular bicuspid extractions
Pre surgery
After treatment
D
D, Occlusal views early during orthodontic retreatment, before surgery, and after reconstruction.
• Figure 19-9, cont’d

660 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
E
F
Mandibular
advancement
E, Articulated dental casts indicating analytic model planning. F, Lateral cephalometric radiographs before and after
treatment.
• Figure 19-9, cont’d

661
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
A
B
• Figure 19-10  A teenaged girl was referred by her orthodontist for surgical assessment. She had a primary mandibular deficiency and maxillary
arch constriction. She also had a Class II anterior open-bite malocclusion. A comprehensive orthodontic and surgical approach was selected. No
extractions were required. Her surgery included a Le Fort I osteotomy in two segments (transverse widening, horizontal advancement, and coun­
terclockwise rotation); bilateral sagittal split osteotomies of the mandible (horizontal advancement and counterclockwise rotation); and osseous
genioplasty (horizontal advancement). A, Frontal views in repose before and after treatment. B, Frontal views with smile before and after
treatment.
Continued

662 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
C, Oblique facial views before and after treatment. D, Profile views before and after treatment.
• Figure 19-10, cont’d

663
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
F
Mandibular counter-
clockwise rotation
Maxillary counter-
clockwise rotation
Arch expansion
G
Pre surgery
After treatment
E
E, Occlusal views during orthodontic decompensation and after treatment. F, Articulated dental casts that
indicate analytic model planning. G, Lateral cephalometric radiographs before and after reconstruction.
• Figure 19-10, cont’d

664 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
A
B
• Figure 19-11  A 16-year-old girl was referred for surgical assessment only after orthodontic treatment was well under way. She had undergone
four bicuspid extractions and compensating orthodontics, but these were unsuccessful with regard to the neutralization of the occlusion. She was
then recognized as having mandibular deficiency with a significant overjet, an anterior open bite, and obstructed nasal breathing. A degree of
gingival recession on the labial aspect of the lower canines was appreciated. The maxillary incisors were procumbent but without space for further
retraction. Reconstruction included a Le Fort I osteotomy in segments (horizontal advancement and transverse widening); bilateral sagittal split
ramus osteotomies (horizontal advancement and counterclockwise rotation); osseous genioplasty (horizontal advancement); and septoplasty and
inferior turbinate reduction. The patient’s gingival recession which was present prior to surgery is being monitored. A, Frontal views in repose before
and after treatment. B, Frontal views with smile before and after treatment.

665
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
C, Oblique facial views before and after treatment. D, Profile views before and after treatment.
• Figure 19-11, cont’d 
Continued

666 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Mandibular counter-
clockwise rotation
Maxillary
segmental
F
G
Pre surgery with 4 bicuspid extractions prior to referral
After treatment
E
E, Occlusal views before surgery and after reconstruction. F, Articulated dental casts that indicate analytic
model planning. G, Lateral cephalometric radiographs before and after treatment.
• Figure 19-11, cont’d

667
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
A
B
• Figure 19-12  A 30-year-old woman was referred for surgical assessment only after orthodontic treatment was well under way. When the patient
was between 9 and 15 years old, orthodontic growth modification and then a camouflage approach were carried out, but these were not suc­
cessful. The current orthodontic treatment was flaring the maxillary anteriors even further forward. The patient was referred to this surgeon and
agreed to a combined surgical and orthodontic approach. Orthodontic retraction of the maxillary anteriors was then initiated. With sufficient orth­
odontic (dental) decompensation, surgery was carried out, including bilateral sagittal split osteotomies of the mandible (horizontal advancement
and counterclockwise rotation); maxillary Le Fort I osteotomy in segments (arch expansion, horizontal advancement, and minimal counterclockwise
rotation); osseous genioplasty (horizontal advancement); and an anterior approach to the soft tissues of the neck (cervical flap elevation, neck
defatting, and vertical platysma muscle plication). A, Frontal views in repose before and after treatment. B, Frontal views with smile before and
after treatment.
Continued

668 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
C, Oblique facial views before and after treatment. D, Profile views before and after treatment.
• Figure 19-12, cont’d

669
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Prior to retreatment
Orthodontics in progress. Spacing between canines and bicuspids requires closure prior to surgery
After treatment
E
Arch expansion
F
G
E, Occlusal views before retreatment, with orthodontics in progress, and after the completion of treatment.
Note the early gingival recession of the maxillary canine and bicuspid teeth as a result of orthodontic mechanics. F, Articulated dental
casts that indicate analytic model planning. G, Lateral cephalometric radiographs before and after treatment.
• Figure 19-12, cont’d

670 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
A
B
• Figure 19-13  A 15-year-old girl was referred for surgical evaluation only after orthodontic treatment was well under way. She has primary man­
dibular deficiency with maxillary arch construction. There is a Class II negative overjet malocclusion despite four bicuspid extractions. The patient
agreed to an orthodontic and surgical approach. After orthodontic (dental) decompensation, she underwent surgery that included a maxillary Le
Fort I osteotomy in segments (horizontal advancement, counterclockwise rotation, transverse expansion, and cant correction); bilateral sagittal split
osteotomies of the mandible (horizontal advancement, counterclockwise rotation, and asymmetry correction); and osseous genioplasty (horizontal
advancement). A, Frontal views in repose before and 3 years after treatment. B, Frontal views with smile before and 3 years after treatment.

671
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
C, Oblique facial views before and 3 years after treatment. D, Profile views before and 3 years after treatment.
• Figure 19-13, cont’d 
Continued

672 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Prior to treatment
Pre surgery with 4 bicuspid extractions
After treatment
E
E, Occlusal views before treatment, with orthodontics in progress, and 3 years after treatment.
• Figure 19-13, cont’d

673
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Maxillary counter-
clockwise rotation
Mandibular counter-
clockwise rotation
Arch expansion
Cant correction
F
G
F, Articulated dental casts that indicate analytic model planning. G, Lateral cephalometric radiographs
before and after treatment.
• Figure 19-13, cont’d

674 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
A
B
• Figure 19-14  A 16-year-old girl was referred for surgical evaluation only after orthodontic treatment was well under way. Lower bicuspid extrac­
tions with the retraction of the anterior dentition were recommended for full decompensation. A computed tomography scan was obtained and
confirmed congenital dysplasia of the condyle–glenoid fossa complex; however, there was a functional temporomandibular joint complex on each
side. There was no suggestion of condylar resorption now or in the past. The reconstruction included a maxillary Le Fort I osteotomy in segments
(arch expansion and horizontal advancement); bilateral sagittal split ramus osteotomies (horizontal advancement); osseous genioplasty (horizontal
advancement); and septoplasty and inferior turbinate reduction. The patient is shown before and after treatment. A, Frontal views in repose before
and after treatment. B, Frontal views with smile before and after treatment.

675
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Continued
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
C
D
C, Oblique facial views before and after treatment. D, Profile views before and after treatment.
• Figure 19-14, cont’d

676 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Arch expansion
F
During retreatment with mandibular bicuspid extractions
After treatment
E
E, Occlusal views with orthodontics in progress and after treatment. F, Articulated dental casts that indicate
analytic model planning.
• Figure 19-14, cont’d

677
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
G
H
G, Computed tomography scan views before reconstruction that indicate congenital dysplasia of the condyle–glenoid
fossa complex. H, Lateral cephalometric radiographs before and after treatment.
• Figure 19-14, cont’d

678 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
A
B
• Figure 19-15  A 15-year-old girl was referred for surgical assessment only after orthodontic treatment was well under way. She had severe
mandibular deficiency and microgenia, and she had already undergone four bicuspid extractions and a full course of orthodontic treatment. An
anterior open bite with procumbent maxillary incisors remained. Evaluation was carried out, including a computed tomography scan, a sleep study,
and speech and otolaryngology consultations. The computed tomography scan confirmed congenital dysplasia of the condyle–glenoid fossa
complex without condylar resorption. Orthodontics were reinitiated, and surgical reconstruction was chosen. The surgical procedures included a
maxillary Le Fort I osteotomy (horizontal advancement, vertical shortening, and counterclockwise rotation); bilateral sagittal split ramus osteotomies
(horizontal advancement and counterclockwise rotation); and osseous genioplasty (horizontal advancement). A mild anterior open bite has recurred,
but this had been stable for several years. A review of the immediate and late postoperative cephalometric radiographs confirmed a consistent
sella–nasion–B-point angle without radiographic evidence of condylar resorption (i.e., no skeletal relapse could be documented). Dental relapse in
the anterior dentition was felt to be the cause of recurrent malocclusion. A, Frontal views in repose before and after treatment. B, Frontal views
with smile before and after treatment.

679
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Sur
u g
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
C
D
C, Oblique facial views before and after treatment. D, Profile views before and after treatment.
• Figure 19-15, cont’d 
Continued

680 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
Prior to retreatment with four bicuspid extractions
Pre surgery
After treatment
E
E, Occlusal views before retreatment (after four bicuspid extractions), before surgery, and then after
treatment.
• Figure 19-15, cont’d

681
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
H
Maxillary counter-
clockwise rotation
Mandibular counter-
clockwise rotation
F
G
F, Articulated dental casts that indicate analytic model planning. G and H, Computed tomog­
raphy scans of the maxillomandibular complex that indicate congenital condyle glenoid fossa dysplasia.
• Figure 19-15, cont’d 
Continued

682 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
the preferred profile aesthetics (i.e., there will be a
suboptimal A-point to B-point relationship in profile).
In borderline cases, a vertical lengthening and a
limited horizontal advancement osseous genioplasty
may provide the necessary degree of aesthetic
compensation.
and vertical position of the chin are important (see
Chapter 37).
Basic Surgical Approach
In addition to lower jaw advancement (i.e., sagittal ramus
osteotomies), maxillary surgery to correct arch-width dis­
crepancies may be required for the individual with primary
mandibular deficiency. This is generally accomplished by
segmental maxillary osteotomies. Through the Le Fort I
down-fracture, any needed improvement in the upper-
lip-to-upper-tooth relationship can also be simultaneously
carried out via the alteration of the vertical height. Any
deficiencies in the horizontal position (i.e., projection)
of the maxilla are also managed. The correction of a maxil­
lary midline discrepancy (i.e., yaw), the aesthetic advantages
of maxillary plane alteration (i.e., pitch), cant correction
(i.e., roll), and intranasal procedures (i.e., septoplasty
and inferior turbinate reduction) can also be simultaneously
accomplished through the Le Fort I osteotomy (see
Chapter 12).
In cases of only borderline maxillary deformity, limiting
the surgery to the lower jaw is generally possible to manage
the malocclusion and to address aesthetic aspects.
• When the decision is made to limit surgery to the
mandible and with only a minimum arch-width dis­
crepancy, the option of narrowing the mandible (i.e.,
a midline symphyseal split) may be considered.
• When only borderline maxillary vertical deficiency
coexists (i.e., not enough to warrant a Le Fort I oste­
otomy), additional surgical vertical lengthening of the
chin may be incorporated to achieve an aesthetic
advantage.
• When mandibular deficiency is combined with a less
than ideal clockwise rotated and vertically deficient
maxilla, the surgically advanced mandible (without
simultaneous Le Fort I osteotomy) may not achieve
I
I, Lateral cephalometric radiographs before and after
treatment.
• Figure 19-15, cont’d 
COMMENT: When there are only borderline
indications for maxillary surgery, the ability to fine-tune
facial aesthetics with a compensating osseous
genioplasty may exist (see Chapter 37).48 Nevertheless, it
is important to understand that a percentage of patients
who present with primary mandibular deficiency will
also have degrees of maxillary dysmorphology that are
best served by double jaw surgery.
Postsurgical Orthodontic Maintenance
and Detailing
If the patient has a presurgical habit of posturing the man­
dible forward (i.e., a dual bite), there may also be a tendency
to do so during the immediate postoperative healing phase.
Intermittent elastics are used during this time 1) to retrain
the masticatory muscles, 2) to provide movement in the
temporomandibular joints, 3) to increase patient comfort,
and 4) to confirm the stability of the occlusion.
If segmental maxillary osteotomies were also carried
out, a prefabricated splint will have been secured to the
maxillary occlusal surfaces during surgery. The orthodon­
tist sees the patient within 24 hours of splint removal
(approximately 5 weeks after surgery) and replaces the
maxillary sectional arch wires with a rigid continuous arch
wire. The maxillary teeth are ligated together to maintain
the arch form. The use of a transpalatal appliance or a
palatal plate may also be used to stabilize and maintain the
arch form if significant transverse expansion was carried

683
CHAPTER 19  Primary Mandibular Deficiency Growth Patterns with or without Maxillary Arch Constriction
or altered mandibular movements (e.g., muscle spasm or
disc displacement with or without reduction); condylar
head erosion; and pain on direct palpation of either tem­
poromandibular joint or of the masticatory muscles.
Occlusal features more likely to be associated with symp­
tomatic TMDs include a centric relation to centric occlu­
sion slide of more than 2 mm; overjets of more than 4 mm;
and the presence of a skeletal anterior open bite. It is likely
for these reasons that White and colleagues found that
TMDs were significantly greater among patients with Class
II skeletal deformities as compared with those patients with
Class III deformities.58 Westermark and colleagues studied
a consecutive series of Class II patients to understand the
effects of orthognathic surgery on the signs and symptoms
of TMD.57 Preoperatively, 43% of the patients reported
subjective symptoms of TMD; postoperatively, 28%
reported such symptoms. This difference suggests an overall
beneficial effect of orthognathic surgery for many individu­
als with Class II mandibular deficiencies.28 Interestingly,
clinical studies indicate that patients with mandibular retru­
sion and TMD do not improve as much from an orthog­
nathic correction as patients with a Class III skeletal pattern
do (see Chapter 9).
Conclusions
In the American and Northern European populations, man­
dibular deficiency is the most frequently seen develop­
mental jaw deformity. This results in an Angle Class II
malocclusion with an excessive overjet and often with a deep
overbite. The mandible and the chin region will be defi­
cient, and the maxilla may also be deformed. The basic facial
dysmorphology in an individual with primary mandibular
deficiency is that of diminished vertical and horizontal
strength in the lower third of the face. There will be lack of
support for the overlying soft tissues that results in an overly
obtuse neck–chin angle, with double-chin formation and
early jowling. The tongue will be retropositioned within a
small oral cavity and have negative effects on the airway.
The laxity of the soft-tissue envelope only worsens through­
out the normal aging process.
The correction of this frequently seen facial imbalance
requires the orthodontic removal of dental compensations,
often with extractions. Orthognathic surgery is performed
for the achievement of a stable occlusion, long-term peri­
odontal health, improvements in the upper airway, and the
enhancement of facial aesthetics.
out.12 Close orthodontic monitoring for skeletal and dental
shifts during the first 6 months after surgery is essential
(see Chapter 17).1,8,9,10,16,22,26,33,54,56,63
The postsurgical orthodontic objectives should be to
bring the teeth into ideal occlusion and to maintain the
surgical result. In the patient in whom the curve of Spee is
to be fully leveled postoperatively, the use of vertical elastics
to close the mid-arch open bites and for the full closure of
the bicuspid extraction sites will also be priorities. This
process can be initiated immediately after surgery.
Complications, Informed Consent,
and Patient Education
The orthodontist is frequently asked to evaluate a preado­
lescent child who is presenting with primary mandibular
deficiency. The clinician may attempt to alter nature’s events
through growth modification maneuvers.53 Clinical studies
now confirm limited success with a growth modification
approach if the goal is to “normalize” the deficient lower
jaw. The camouflage orthodontic approach that often
follows may neutralize the occlusion, but it will not improve
baseline upper airway dysfunction, and it will not enhance
the appearance of a retrusive profile. Furthermore, it may
have detrimental effects on the periodontium (see Figs. 19-1
through 19-5). The onus is on the clinician to communicate
the shortcomings of these isolated orthodontic maneuvers
to the patient and the family before beginning treatment.
After a combined surgical and orthodontic approach is
agreed to, the clinician’s ability to communicate the poten­
tial risks, complications, and benefits of the recommended
coordinated plan to the patient and the family is essential
(see Chapter 17).19,24 The patient’s and the family’s informed
decision to proceed provides the basis for shared responsibil­
ity of the outcome (see Chapter 7).
Temporomandibular Disorders:
The Effects of Orthodontics and
Orthognathic Surgery
Temporomandibular disorders (TMDs) include various
symptoms and signs of the temporomandibular joint, the
masticatory muscles, and related structures. The symptoms
and signs may include a spectrum of referred head and neck
pain; joint noise (e.g., popping, clicking, crepitus); reduced
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686

20
Maxillary Deficiency with Relative
Mandibular Excess Growth Patterns
JEFFREY C. POSNICK, DMD, MD
• Functional Aspects
• Clinical Characteristics
• Dental Characteristics
• Radiographic Findings
• The Role of Growth Modification in the
Preadolescent Patient
• Orthodontic Camouflage Approach
• Surgical Camouflage Approach
• Definite Reconstruction
• Postsurgical Orthodontic Maintenance and
Detailing
• Complications, Informed Consent, and
Patient Education
• Malocclusion after Orthodontics and
Orthognathic Surgery
• Temporomandibular Disorders: The Effects of
Orthodontics and Orthognathic Surgery
• Suboptimal Facial Aesthetics after
Orthognathic Surgery
• Conclusions
There is a strong family tendency for a Class III skeletal
pattern. The so-called “Habsburg jaw” within the royal
European family is well documented.58,104,106,122,124 The fre­
quency of Class III skeletal patterns among white people of
European or North American ancestry is reported to have
a prevalence in the low single digits. There is a somewhat
higher prevalence of Class III skeletal patterns among Afri­
cans than among Caucasians.27 Data from Japan, Korea,
and China confirm a more frequent Class III pattern among
Asians than among any other subgroup (i.e., >4%).28,117
Incidence rates of Class III malocclusion of as high as 13%
have been reported in specific regions of Asia.119 Lew and
colleagues examined occlusal parameters in 1050 Chinese
schoolchildren who were between 12 and 14 years old.48
They found an incidence of 12.6% for Class III malocclu­
sion, 58.8% for Class I occlusion, and 21.5% for Class II
malocclusion. Samman and colleagues investigated 300
Chinese individuals residing in Hong Kong who were
known to have dentofacial deformities and who had been
referred to an “orthognathic surgery clinic.”91 After exclud­
ing those individuals with cleft lip and palate, 222 study
patients remained. Forty-seven percent of these individuals
(n = 104) were found to have a Class III skeletal
malocclusion.
Despite hereditary tendencies, the development of a
Class III jaw disharmony is believed to be multifactorial and
complex.8,33,39,57 Alternatively, it has been documented that
environmental factors have a significant effect on vertical
facial growth (see Chapter 21). The combination of an
individual’s hereditary tendency toward a Class III skeletal
pattern and a longstanding, forced mouth breathing, open-
jaw posture during growth explains the occasional occur­
rence of a long face growth pattern (i.e., excess vertical
growth) with Class III negative overjet malocclusion.29 An
outlier for a Class III skeletal pattern is the impaired midface
growth that is seen in many individuals from all back­
grounds with repaired cleft palates (see Chapters 32, 33,
and 34). Another commonly seen clinical pattern is the
individual with maxillary vertical deficiency and a promi­
nent pogonion (i.e., pseudoprognathism) as a result of “over
closure” (see Chapter 23).97,99,109
Developmental Class III skeletal problems generally result
from maxillary deficiency in combination with relative
mandibular excess. Through trial and error, it is now recog­
nized that either growth modification in the preadolescent
patient or camouflage treatment in the teenager or adult as
a method of managing this type of dentofacial deformity is
at best relatively ineffective. In addition, even mild degrees
of a Class III facial appearance are aesthetically noticeable
as unattractive by the general population.76 Therefore, the
perceived need for treatment (i.e., de facto orthognathic
surgery) for the Class III patient—whether by the public,
the evaluating clinicians, the affected individual, or the
patient’s family and friends—will be high.13,72,78,125

687
CHAPTER 20  Maxillary Deficiency with Relative Mandibular Excess Growth Patterns
An additional source of data regarding the prevalence of
individuals with skeletal Class III is the National Health
and Nutrition Examination Survey III, a large-scale epide­
miologic survey of the U.S. population that was carried out
during the 1990s (see Chapter 3).77 The data from this study
confirm that Class III problems increase from early child­
hood through adolescence.1,18 This can be explained by the
expected late growth spurt in the mandible as compared
with the maxilla. The study also confirmed that the presence
of 2 mm or more of negative overjet is about twice as likely
to occur among African Americans than among Caucasian
Americans or Mexican Americans. Data from a U.S. public
health survey of youths between the ages of 12 and 17 years
indicates that about 14% have a mandibular first molar that
is mesial in relation to the maxillary first molar.42
With regard to treatment, by the late 1800s, both
Edward Angle, an orthodontist, and Vilray Blair, a surgeon,
recognized that orthodontic treatment alone could not solve
the Class III skeletal problem.15 Angle suggested that the
only possible way to correct a true mandibular protrusion
was with a combination of orthodontics and surgery.2 By
the late 1800s, the initial orthognathic procedures were
carried out to “set-back” the prominent mandible (see
Chapter 2).
Functional Aspects
• Predictable articulation errors in speech result from a
Class III malocclusion (see Chapter 8).
• Chronic obstructed nasal breathing is commonly seen in
the presence of maxillary deficiency (see Chapter 10).
• Characteristic difficulties with swallowing and chewing
as a result of a Class III malocclusion are expected (see
Chapter 8).
• Wide lip separation (often with upper lip hypotonia) and
mentalis strain required for lip seal are commonly seen
in the presence of a significant negative overjet.
• Detrimental long-term effects on the dentition and
the periodontium that result from a Class III malocclu­
sion (secondary occlusal trauma), dental crowding, or
previous camouflage orthodontics are often seen (see
Chapter 6).
• The incidence of temporomandibular disorder (TMD)
may be higher among these patients than among indi­
viduals with normal jaw harmony and occlusion (see
Chapter 9).
Clinical Characteristics
Profile View
• Long chin–neck length and acute angle with a visually
accentuated inferior border of the mandible
• Prominent chin with a reduced labiomental fold
• Protrusive and thick lower lip and vermillion
• Sunken-appearing midface (A negative vector relation­
ship between the ocular globe and the lower eyelid as a
result of anterior maxillary deficiency is a frequent
finding.)
• Deflated, short, hypotonic appearance of the upper lip,
with a thin vermillion
• Acute nasolabial angle
• Columella of the nose oriented more horizontally
Frontal View
• Sunken-appearing cheeks (i.e., the impression of flat
cheek bones)
• Middle one third of the face appears flat and long
• Increased scleral show (i.e., pulling down of the lower
lids)
• Narrow alar base with paranasal flattening
• Flat and relatively short upper lip with reduced vermil­
lion exposure
• Normal to deficient maxillary tooth to upper lip relation­
ship frequently seen
• Mandible appears prominent
• Reduced labiomental fold
Dental Characteristics
• Minimal attached gingiva over the labial aspects of
the mandibular anterior teeth is frequently seen (see
Chapter 6).
• Mandibular incisors are usually upright or lingually
inclined.
• Interdental spacing with flared mandibular incisors may
also be seen, especially in the presence of an anterior
open bite with lip incompetence.
• Class III malocclusion (molar and canine) with anterior
open bite, negative overjet, and posterior crossbites is
frequent.
• Narrow maxillary arch width is seen as excess negative
space in the buccal corridors.
• Dental crowding with flared maxillary incisors is
frequent.
Radiographic Findings
• Maxillary horizontal deficiency
• Concave anterior maxilla consistent with a negative
vector relationship of the ocular globe to the lower eyelid
• Flat, counterclockwise-rotated maxillary plane
• Procumbent maxillary incisors
• Flat base of the nose with retrusive pyriform rims
• Altered lower anterior facial height (either short or long)
• B-point is anterior to or in front of A-point in profile
(i.e., natural head position)
• Negative overjet to the occlusion
• Prognathic-appearing mandible
• Lingually inclined mandibular incisors frequently found
• Chin morphology varies, but it is generally dysmorphic.
Frequent patterns of chin dysmorphology include verti­
cal excess with either a prominent or flat pogonion.

688 SECTION 3  Classic Patterns and Presentations of Dentofacial Deformity
overjet. Although the authors were encouraged, many
unknowns remained, including the ideal age for this type
of orthopedic traction; the effect of the direction of force
on the rotation of the palatal and mandibular planes; the
long-term effects on the temporomandibular joints; and the
need for retention to prevent catch-up growth of the man­
dible or relapse of the maxilla afterward. DeClerck’s ongoing
prospective clinical trial of this promising work on a larger
sample of patients (as well as the work of other independent
researchers) will help to answer these questions and to deter­
mine the true effectiveness of a growth-modification
approach that involves temporary skeletal anchorage and
elastics.21,92
Orthodontic Camouflage Approach
The decision to proceed with an orthodontic camouflage
approach frequently implies that orthopedic growth modi­
fication mechanisms to overcome the Class III pattern were
either ineffective earlier during the patient’s life or that the
patient presents to the orthodontist at an age at which such
mechanisms are not feasible. In the adolescent or adult,
when a significant reverse overjet remains, the possibility
of achieving even the limited parameter of a neutralized
occlusion with the use of only orthodontic maneuvers is
questionable. In fact, doing so may require the further
displacement of the teeth outside of the supporting alveolar
bone as a means of compensation for the underlying jaw
discrepancy. The extraction of the mandibular first premo­
lars in combination with Class III elastics and extraoral
forces on the maxilla (i.e., the proclination of the maxillary
incisors) will improve the occlusion for the Class III patient;
however, treatment generally falls short of expectations and
rarely produces acceptable facial aesthetics. Even minimal
retraction of the lower incisors often magnifies the chin’s
prominence, which is likely a primary reason why the
patient sought treatment. Furthermore, camouflage ortho­
dontics will not succeed in altering any combined vertical
skeletal problems. In fact, the orthodontic mechanisms that
are used to reposition the dentition often extrude the pos­
terior teeth, thus further accentuating the vertical facial
disproportion.
Individuals who present to the orthodontist with a Class
III skeletal pattern will usually have dental compensation
that developed as an adaptive biologic mechanism during
growth. Typically, the upper incisors are at least somewhat
proclined relative to the maxillary basal bone. The lower
incisors are often overly upright relative to the basal bone
of the mandible. If an orthodontic camouflage approach is
chosen, then the upper incisors are proclined, and the lower
incisors are retropositioned even further.
It is not uncommon for the orthognathic surgeon to see
an adult in consultation who is emotionally exhausted after
having undergone failed growth modification followed by
disappointment after additional years of camouflage ortho­
dontics. The individual may present with 1) significant
residual malocclusion (i.e., effects on speech, swallowing,
The Role of Growth Modification in the
Preadolescent Patient
Since the mid 1800s, clinicians have developed and used
devices to attempt to correct and prevent a worsening Class
III skeletal pattern during childhood. Despite this extensive
history, little long-term success has been documented
involving the use of these devices. Techniques have included
use of a chin cup to “hold back” the mandible; a face mask
to “grow” the maxilla; and, more recently, the use of skeletal
anchorage devices and elastics in an attempt to do both.
Most studies have found no difference in the ultimate
size of the mandible between children with Class III condi­
tions who were treated with a chin cup and those who were
not.105 Wylhelm-Nold and colleagues presented some evi­
dence that the use of the chin cup in preschool-aged chil­
dren was able to decrease mandibular anterior growth if
good compliance was achieved.123 Unfortunately, this did
not prevent the mandible from continuing an excess growth
pattern later during childhood, after the chin cup treatment
was stopped. In fact, a rebound accelerated growth effect
was documented. What chin cup therapy may accomplish
is a change in the growth vector of the mandible, with more
downward and backward (clockwise) rotation.37 These sec­
ondary changes have their own negative effects on facial
morphology and occlusion (i.e., the law of unintended
consequences).
With the realization that the presenting maxillary defi­
ciency should be the primary focus of the correction for
most skeletal Class III individuals, growth modification
moved toward methods of stimulating the upper jaw. The
Delaire face mask has been used extensively to pull the
maxilla forward.24 The work of Baccetti and McNamara
confirmed that use of the Delaire face mask for the indi­
vidual with maxillary deficiency is more likely to have effect
when it is used before the patient is 8 years old.6,21,92 After
this age, tooth movement (dental compensation) and man­
dibular clockwise rotation will be the likely consequences
of this form of treatment rather than the hoped for hori­
zontal maxillary projection. In addition, many children
experience recurrence of the deformity after face mask
therapy is discontinued. It is unlikely that face mask (for
the maxilla) and chin cup (for the mandible) interventions
will be effective in the long term for preventing the need
for orthognathic surgery in all but mild cases. An accepted
guideline is that more than 2 to 4 mm of reverse overjet in
the preadolescent child indicates that surgery will eventually
be needed if both facial and dental correction are sought.
DeClerck and colleagues used orthopedic traction on the
maxilla and compression on the mandible with temporary
mini-plate skeletal anchorage and elastics in a limited number
(n = 3) of 10- to 11-year-old children presenting with skel­
etal Class III malocclusions.25 Pure bone-borne orthopedic
forces were applied with intermaxillary elastics on the skel­
etally anchored mini-plates. This approach was shown to
either enhance midface growth or to hold back the man­
dible; in any case, the intent was to produce a corrected

689
CHAPTER 20  Maxillary Deficiency with Relative Mandibular Excess Growth Patterns
is generally misguided and will produce an unnatural and
“operated” look. Upper lip augmentation and lower lip reduc­
tion procedures in the Class III patient also tend to look
and feel unnatural.
To be fair to the patient and his or her family, the limita­
tions of compensating orthodontics followed by surgical
camouflage should be disclosed before the initiation of
treatment.
Definitive Reconstruction
Timing of Orthognathic Surgery
Skeletally immature individuals with true mandibular excess
can be expected to outgrow any early orthodontic or surgi­
cal corrections and later require further treatment.7,17,83,90
Indirect methods of assessing growth maturity (e.g., a
hand–wrist film to determine bone age) are not accurate
enough to be used in isolation for planning the timing of
surgery. A reasonable method to assess growth maturation
is through the analysis of serial lateral cephalometric radio­
graphs. These radiographs can be used in two ways: for a
cervical vertebral analysis or to make sequential direct man­
dibular measurements. Surgery is delayed until the decelera­
tion of growth can be documented. The use of a quantitative
condylar head bone scan can also be helpful to evaluate the
growth of the mandible in the adolescent, but both false-
positives and false-negatives may occur. If the Class III
condition is largely the result of maxillary deficiency,
gauging the preferred timing of surgery is more straightfor­
ward, because the late postsurgical growth of the mandible
is less likely (see Chapter 17).
Alexander and colleagues completed a study of craniofa­
cial growth changes in Caucasians with untreated Class III
malocclusions by using longitudinal cephalometric records
(n = 103).1 In girls, the mandibular growth spurt generally
occurred between the ages of 10 and 12 years. In boys, the
growth spurt was usually between the ages of 12 and 15
years. In some of the Class III subjects, limited degrees of
mandibular growth relative to that of maxillary growth were
documented to continue after the adolescent spurt. After
the age of 13 years in girls and 15 years in boys and until
closer to the age of 17 years, annual increments of man­
dibular growth were often between 1.5 mm and 2.0 mm,
whereas increments of midface length dropped to less than
1 mm. The authors concluded that the differential growth
behavior of the two jaws among individuals with Class III
conditions may result in recurrent jaw disharmony and
malocclusion when orthodontic or surgical treatment is
undertaken before or during puberty.
Pre-Orthodontic Periodontal Checklist
(see Chapter 6)
• Assess for active gingivitis or periodontitis and the need
for treatment.
and chewing) 2) deteriorating periodontal health (i.e., crest
bone loss and gingival recession associated with lower ante­
rior and upper posterior teeth), 3) often with chronic upper
airway obstruction (i.e. deviated septum, hypertrophic infe­
rior turbinates, and tight nasal apertures) and 4) self-esteem
and body image issues related to the facial disproportion
and disappointment with failed treatment (Figs. 20-1
through Fig. 20-4).
All too often, the orthodontic camouflage approach was
centered on the achievement of a neutralized occlusion as
the primary objective, without full disclosure to the patient
and his or her family. If the goals of treatment are to achieve
long-term ideal dental health, improved facial aesthetics
and an open upper airway, few treatment plans for the Class
III patient would include a camouflage approach. Clear
contraindications to an orthodontic camouflage approach
include the following:
• Moderate or severe Class III patterns (i.e., >4 mm of
reverse overjet)
• Moderate to severe vertical skeletal discrepancies
• Significant dental crowding in the lower jaw and sig­
nificant anterior dental protrusion in the upper jaw
• A concern that the planned orthodontic mechanics
may cause periodontal deterioration
• A desire for enhanced facial aesthetics
• A need to open the upper airway
Surgical Camouflage Approach
Some orthodontists have been buoyed in their efforts to
neutralize the occlusion in the individual with a skeletal
Class III condition on the basis of a belief that limited
cosmetic surgery can improve the facial appearance and thus
avoid major orthognathic procedures. Attempts at surgical
camouflage for the patients with a Class III skeletal pattern
may include a combination of reduction genioplasty; onlay
grafting to the midface; upper lip augmentation; lower lip
reduction; and neck and chin soft-tissue procedures. In
general, these camouflage surgical techniques are ineffective,
irreversible, and disappointing.
Often, a prominent chin and apparent flat cheek bones
are perceived by the patient to be the aesthetic issues.
Although a reduction genioplasty seems to be a logical
approach, the surgical reduction of the prominent chin as
an isolated procedure in the absence of orthognathic surgery
rarely satisfies the facial aesthetic concerns. “Setting back
the chin” generally leads to drooping (i.e., ptosis) of the
associated soft tissues; irregularities of the mentalis muscles
when in function; and a double-chin appearance of the
neck. Submental lipectomy may then be considered in an
attempt to improve the chin ptosis and the appearance of
the neck, but with only limited effects. Onlay grafts or
implants involving the anterior maxilla have been used in
an attempt to camouflage the midface deficiency. These
perinasal implants run the risk of looking and feeling unnat­
ural. Augmentation of the zygomas and the infraorbital rims
Text continued on p. 694