Orthognathic

Surgical Orthodontics
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Dentofacial Deformity:
 Refers to deviations from normal facial
proportions that are severe enough to be
handicapping
 Affects individuals in two ways:
1. Jaw function is compromised
2. Leads to discrimination in social interactions

 Handicapping malocclusion↔ Dentofacial
deformity
“Who is a candidate for surgery in addition to
orthodontics?”
Severe skeletal or very severe dentoalveolar
problem
“What makes a problem too severe for
orthodontics alone?”

Three possible treatment options for a jaw
discrepancy:
1. Growth modification
2. Camouflage
3. Surgical repositioning

 Growth modification
 Current consensus:
1. Pattern of growth can be modified in a
favourable way
2. Extent of change is rather limited

 Treatment inevitably displaces teeth in the
direction of the correcting occlusal
relationship- dental compensation for skeletal
discrepancy
 Unless very favourable growth occurs, the
dental occlusion is corrected better than the
chin deficiency

 Camouflage: In a patient too mature to grow
much more
 Surgery:
- Only way to correct a jaw discrepancy
- “Reverse orthodontics”

“Envelope of Discrepancy”

 Transverse Envelope of Discrepancy

“What makes a problem too severe for
orthodontics alone?”
- In a child
- In an older individual

Development of Surgical-
Orthodontic Treatment
 Before the 1960’s- exclusively reserved for
mandibular prognathism
 Body ostectomy was used to set the mandible
back
 Surgical treatment was done independent of
orthodontics

 Unwillingness of the surgeon or orthodontist
to use the orthodontic appliance for
stabilization

 With steel orthodontic appliances better
control than with the heavier but les precise
arch bars
 Orthodontics could be done before and after
surgery

Evaluation of Facial Soft Tissues:
 The Soft Tissue Paradigm:
- Angle Paradigm: To produce perfect
occlusion of teeth and facial beauty would
naturally follow
- Modern Model:
Soft tissues largely determine the limitations
of orthodontic and orthognathic treatment

 Clinicians must establish treatment plans
for the dentition and facial skeleton by
“reverse engineering”
1. It is revolutionary
2. Diagnosis and treatment planning must be
approached differently.
Places greater emphasis on clinical
examination

Growth and Maturation of Soft
Tissues:
 Lips:
- Lip separation at rest is common in children.
Merely a reflection of incomplete soft tissue
growth.

- Vertical growth of upper lip is achieved in
females by 14 and lower lip by age 16
- In males growth of both lips continues into the
late teens

- Lip thickness
Girls have greater lip thickness than boys at
all ages
 Nose:
- Grows more vertically than AP

- Spurt of adolescent growth occurs in boys
- Dorsal hump develops in Class II
malocclusion
 Soft tissue chin:
- In preadolescent girls, soft tissue chin is
greater than boys
- Increased chin projection occurs in males
during growth

Soft tissue changes in Younger
Adults:
 Lips become thinner
 Interlabial line descends
 Philtral columns become less prominent
 Commisures drop in relation to midphiltrum
 Nasolabial folds become more prominent

Gender Differences:
 In Males:
- Profile straightens
- Soft tissue thickness at pogonion increases
 In Females:
- Profile does not become straighter
- Soft tissue chin thickness decreases
Trend to show less upper and more lower
incisor

Changes at Older Ages:
 Nasal Projection:
- Increase in nasal projection and “droop” of
the nasal tip
 Lip Thickness:
- Less prominent and change in lip drape
 Nasolabial Changes:
- Clockwise rotation of the nasolabial complex

Current Concepts of Smile
Evaluation:
 It is important to consider the soft tissues
during facial animation, not just at rest
Methods for Smile Evaluation:
 The dynamic display zone
 Ackerman and Proffit proposed video clips of
anterior tooth display

 Ackerman et al suggested differentiating
between posed and spontaneous smiles
 Spontaneous smile↔ Duchenne smile

 Ackerman et al used a “smile mesh” to
analyze photographs of posed smiles

Smile Related to the Natural
Dentition:
 The amount of
incisor and gingival
display:
- Elevation of the lip
should stop at or near
the gingival margin of
the maxillary incisors
- Males show less upper
and more lower incisors

 Transverse Dimension of the Smile:
- “Buccal corridors” or “negative space”
- Heavily influenced by the anteroposterior
position of the maxilla

 The Smile Arc:
- Relationship of the
curvature of the upper
anterior teeth to the
curvature of the lower
lip on smile

- Consonant or nonconsonant smile arc
- Orthodontic treatment, by flattening the smile
arc, can make patients look older

Smile Arc Flattening During
Orthodontic Treatment:
 Bracket placement based on tooth
measurements
 Bracket placement that leads to superior
repositioning of the maxillary incisors relative
to the posterior segments

 Bracket placement that elongates lower
incisors
 Maxillary incisor intrusion to decrease
gingival display

Other Factors:
 Habits
 Attrition

Assessment of Facial Soft
Tissues: Frontal View
 Vertical Facial Proportions:
- Facial thirds

- Commisure height no
more than 2-3mm more
than philtrum height
- Base of the nose has a
“gull in flight” contour

 Excess lower face height has two major
components: vertical maxillary excess and
excess chin height

 Tooth-lip relationships:
- In adolescents, 3-4mm of incisor display at
rest is normal
 Excessive incisor display:
- Judged better at rest
- May be a result of both hard and soft tissue
factors:
1. Short philtrum height

2. Vertical maxillary excess
3. Excessive crown height
4. Lingually tipped maxillary
incisors
Inadequate Incisor Display:
1. Excessive philtrum height
2. Vertical maxillary deficiency
3. Inadequate crown height
4. Flared maxillary incisors

Transverse Facial Proportions:
 “Rule of fifths”

The Central Fifth:
- Delineated by the inner
canthus of the eyes
- Inner canthal distance=
alar base of nose
The Medial Fifth:
- Width of mouth=
interpupillary distance
- Line from the outer
canthus should coincide
with the gonial angles

The Outer Fifth:
- Measured from the outer canthus to the ear
helix

Soft Tissue Proportions:
Profile View

Soft Tissue Proportions:
Profile View
 Projection of the Forehead:
- Glabella should be coincident with the base
of the nose
- Should slope posteriorly at a 5° angle
 Nasal and Paranasal Relationships:
- Bigger the nose, more the prominence of the
lips and chin needed

- Prominence of the paranasal areas

 Lip projection:
- Normal lip projection is seen when lips are
slightly everted with several mm of vermilion
displayed
- Dental protrusion

- Relationship of the lips to the nose and chin:
In a chin deficient patient, lower lip may
appear full or procumbent

 Mentolabial sulcus:
- Affected by the degree of
lip support from the
incisors and by face
height
 Throat Form:
Lip-chin-throat angle:
- Angle between the lower
lip, chin and R point

 An obtuse angle reflects:
- Chin deficiency
- Retropositioned mandible
- Lower lip procumbency
- Excessive submental fat
- Low hyoid bone position

 Chin-throat length:
- Distance from the soft tissue pogonion to the
R point

 Chin-neck angle:
- Also termed cervicomental angle
- Varies between 105-120º

Diagnosis: Gathering
and Organizing the
Appropriate Information

 Diagnosis requires two things: collecting an
adequate database and distilling from it a
problem list
 The goal of diagnosis is to discover the truth
about the patient
 The objective of treatment planning is wisdom

Interview:
 Diagnostic data from the interview is of
three types:
1. The patient’s Chief Complaint
2. Patient’s socio-psychological status
3. Medical-dental history

Chief Complaint:
- Patient’s major reason for seeking
treatment
- Necessary to ask a series of leading
questions
- Patient’s fall into two broad groups:
1. Age range from teens to early forties-
generally concerned about appearance and
function

2. Age range from 35-55: concerned about
specific health related problem
 Chief complaint gives insight into what is
most important for the individual

Social-Psychological Status:
1. Why are you seeking treatment and why
now?
2. What do you expect as a result of treatment?
- Motivation: Can be internal or external
- Important to explore motivation for two
reasons:
i. Cooperation with treatment and tolerance of
treatment procedures

ii. Patient satisfaction with treatment
Expectation:
- The clinician needs to understand how
realistic the expectations are
- Is it realistic to expect that TM joint pain will
disappear?
- Is it realistic to expect a great improvement in
interaction with others?

Physical Status: Health History
1. What is the patients present condition?
2. What, if anything, may change in the near
future that would affect the course of
treatment?
- Seek to evaluate not only the physical
health but also the developmental status
- For dentofacial patients, chronic conditions
are of greater concern

Clinical Examination:
1. Health of the hard and soft tissues
2. Oral function, including TM joint evaluation
3. Facial proportions/ esthetics
Health of Hard and Soft Tissues:
Dental Evaluation:
Midline periapical radiographs may be needed

 Periodontal Health:
- Periodontal breakdown and pocketing must
be evaluated
- Adequacy of attached gingiva must be
ascertained- gingival grafts may be needed

 Oral Function:
- Mastication
- Speech: degree of adaptation in this regard is
remarkable
- Neuromuscular adaptation
- TM joint problems:
Dentofacial patients are remarkably similar to
patients with normal facial proportions in the
prevalence of TM Joint problems

- General guideline: Range of motion and pain
should be evaluated
- In case of TM joint problems, a splint to
overcome muscle spasticity should be
prepared.

Diagnostic Records:
- Dental casts
- Panoramic and lateral cephalometric
radiographs
- PA cephalogram in patients with significant
asymmetry
- Photographs: A minimum set of four
photographs-

1. Frontal, with lips relaxed
2. Frontal smile
3. 45 degree (three quarter), lips relaxed
4. Profile, in natural head position

- In cases of lip
incompetence, image
reflecting lip strain
- Submental view:
mandibular/ midface
asymmetry; nasal tip
form

- Special problem areas such as loss of
attached gingiva
TM Joint Imaging:
- Panoramic view gives a good picture of
condyles
- Transcranial, tomographs, CT, arthrography,
MRI

 Dental Casts: Articulator Mounting?
1. Not required in patients with no TM joint
symptoms with no anterior or lateral shifts
2. Desirable in patients with TM joint problems
3. In planning surgical treatment to reposition
the maxilla
Semiadjustable articulator is satisfactory

Data from Diagnostic Records:
 Cephalometric Analysis
 Analysis of PA Cephalometric Films:

 Analysis of Hand-Wrist Radiographs:
- Question for dentofacial patients is whether
they have reached the adult levels of growth
- Accuracy declines towards the adult end of
the scale. For example: Patients with
mandibular prognathism
- The most accurate measure is obtained from
superimposing tracings from lateral
cephalometric films

Deriving a Problem List from the
Database
 First step is to separate the pathologic
problems from the developmental problems
- Periodontal disease, psychological disorders,
degenerative TM joint changes
 Alignment and symmetry of the dental
arches
 Effect of dentition on facial esthetics:
- Lip separation at rest

 Transverse Dental and Skeletal
Relationships:
- Focus is on posterior crossbite and anterior
midlines
- Distinction between skeletal and dental
crossbites

Treatment Planning:
Optimizing Benefit to
the Patient

Treatment Planning: Optimizing
Benefit to the Patient
 Treatment possibilities for
Dentofacial Deformity:
1. Growth modification
2. Camouflage
3. Surgery

Camouflage:
- Camouflage means correcting the obvious
aspects of the deformity
- Problem: Being able to predict whether it
would be satisfactory

 Class II camouflage:
1. Retraction of protruding maxillary incisors:
- Teeth should not be retracted to
compromise upper lip
- Reduction rhinoplasty
2. Displacement of teeth of both arches:
- Puts the incisors in an unstable position
- Tends to accentuate chin deficiency

- Giving the dentition a “Class II elastics” trip is
almost never satisfactory
- Addition of genioplasty
3. Repositioning the chin and/or nose:
- To improve balance between lower incisors
and chin
- Makes retraction of upper incisors more
acceptable

 Class III camouflage:
- Retracting the mandibular incisors into a
premolar extraction site usually is not a good
idea
- Extraction of one lower incisor; potential tooth
size discrepancy is compensated
- Onlay grafts and reduction genioplasty

Bottom Line:
In dentofacial deformity,
orthodontic camouflage is much
more likely to be successful in
Class II problems than in Class III
problems

 Camouflage of Asymmetry:
- Nose is likely to tilt in the same direction;
dental midlines closer together
- Emphasis on correcting the maxillary midline
- Nasal asymmetry must be addressed

- Moving the chin laterally can conceal the
underlying jaw asymmetry

Surgical Camouflage:
 Chin Surgery:
1. Addition of some extraneous material
2. Inferior border osteotomy
- Allows repositioning in all the three planes

- When moved laterally, may be
necessary to add material
- Advantage of inferior border
osteotomy:Ratio of hard to soft
tissue change is quite
predictable

- When advanced: soft tissue moves by 60%
- Reduction genioplasty: 50% soft tissue
reduction
- Vertically: soft tissue moves same amount

Augmentation of Deficient Facial
Surfaces:
 Midface and Paranasal deficiency:
- Lower eyelid tends to droop
- High LeFort I osteotomy, augmentation

Soft Tissue Procedures:
 Esthetic Lip Surgery:
- Reduction cheiloplasty for hypermobile lip
 Lengthening of the Short Philtrum:
- V-Y cheiloplasty as an isolated procedure or
in combination with LeFort I osteotomy,
rhinoplasty

Orthognathic Surgery:
 Changes in Width:
Maxilla
- Technically it is possible both to widen and
narrow the maxilla

- 10mm of change is maximum
- Major constraints are palatal soft tissues
and soft tissues laterally
- With a segmental osteotomy, there is more
opening posteriorly
- Considerable relapse tendency
1. Skeletal relapse: Permitted by orthodontic
tooth movement
2. Dental relapse

- 40% decrease in intermolar width achieved
at surgery
- Similar to RPA
- First attempts: Midpalatal incision
- Osteotomy in the lateral buttress region

Mandible
- Possible to narrow
anteriorly but impossible to
widen posteriorly

 Anteroposterior and Vertical
Changes:
Maxilla
- Can be moved forward and upward
- Forward movement: 10mm and upward
10mm or more
- Major limitation to forward movement is upper
lip

- Velopharyngeal incompetence:
- Unrecognized submucous cleft:
Phonation cephalometric radiograph

Superior repositioning of maxilla:
- Great concern that neuromuscular adaptation
would not occur
- Fears heightened by denture wearers
- Mandibular posture does respond to vertical
changes in the maxilla

- Pressure receptors in the PDL of maxillary
posterior teeth

 Posterior movement of maxilla:
 Moving the maxilla down is difficult from the
point of stability

Mandible:

- Moving the mandible forward or back nearly
always causes vertical changes
- Three possibilities:
1. Down anteriorly and up posteriorly
2. Along the mandibular plane
3. Up anteriorly and down posteriorly

 Two important guidelines:
1. Lengthening the ramus should be avoided
2. Planning surgery to elevate the posterior
maxilla

 Dentoalveolar Surgery:
- Can be repositioned in all three planes
- Key is maintaining an adequate blood supply

 Guidelines:
1. Nature of tooth movement
2. Size of dentoalveolar segments

 Timing of Surgical Treatment:
 Orthognathic surgical procedures have little
impact on subsequent growth
- Deformity caused by excess growth
- Deformity caused by deficient growth
Surgery can be done sooner in deficiency
than in excess growth problems

Logical Sequence of Treatment
Planning:
Pathologic Vs Developmental Problems
 Can be divided into three major groups:
1. Chronic systemic disease states
2. Local conditions
3. Psychologic or emotional problems

 Chronic Systemic Diseases:
Arthritis
- Principle in planning treatment: Manipulation
of the TM Joint should be as little as possible
- In children with JRA, functional appliances
are not advocated
- Surgical advancement should be avoided
- Superior repositioning of the maxilla with
genioplasty

Diabetes
Has two major implications:
1. Healing is decreased
2. Rapid and severe periodontal bone loss can
occur

 Local Conditions:
 Trauma
1. Teeth that have been traumatized are more
likely to undergo pulpal and periodontal
changes
- Severe root resorption may occur in
traumatized teeth
2. Evaluation of growth and growth potential

 Dental Disease:
 Restorative Problems:
- Caries control calls for temporary
restorations: composite resins and amalgam
are satisfactory
- Use of sodium fluoride rinse
- Patients with fixed bridges- sectioning the
bridge so that abutments can be repositioned

 Brackets can be bonded on a replacement
tooth

- As a general rule, it is better to retain an
existing crown
- Poor crown margins and exaggerated contour
make repositioning impossible

 Periodontal Problems:
- Definitive periodontal procedures to be
deferred
- Regular recall at 2-3 month intervals
 Quantity and quality of attached
gingiva:
- Gingival attachment is stressed by
orthodontic procedures that expand the arch
and by vestibular incisions

- Gingival grafts should not be delayed

 Psychologic Problems:
- Considerable caution in proceeding with
elective treatment
 Prioritizing the Developmental
Problem List:
- The first step is to place the problems in
priority order
- Maximize benefit to the patient

- Patient’s chief complaint must be considered
carefully
- Patient’s must agree with the prioritization of
the problem list

Interaction, Compromise and
Cost-Benefit Ratio:
 Interaction:
- Solutions which interact positively by solving
multiple problems should be preferred
 Compromise:
- May be necessary because not all problems
can be solved optimally
 Cost-Benefit Ratio

Prediction as a Treatment
Planning Tool:
 Manual Cephalometric Prediction:
 Tracing Overlay Method
- Simulates the effect of mandibular surgery
- Limited to surgery that does not affect the
maxilla

1. It helps to have dental casts when the
prediction is carried out. Trace the incisal
and cusp outlines of all the teeth.
2. Major orthodontic tooth movement should
be simulated on a diagnostic set up
3. Estimates are based on changes in lip
position at rest

Template Method
 When maxilla will be
repositioned, major
tooth movements,
chin repositioning

- Templates are made for the entire maxilla
with a one-piece or two-piece osteotomy
- Importance of locating the condyle as
accurately as possible
- Possibility of repositioning the chin-
template prepared by tracing the anterior
and inferior outlines of the chin

Computer Prediction:
1. A digital model of the
ceph tracing is
entered into the
computer program
2. A lateral image of the
patients profile closely
matching the
cephalogram must be
captured

3. The digital tracing is “sized” to fit the facial
image
4. A “treatment screen” provides the clinician
with “handles” to move the hard tissues
5. The computer program applies the embedded
soft tissue algorithms

6. The software “warps” the profile image to
match the prediction line drawing
7. A quantitive table records the exact
movements in millimeters
Accuracy of computerized predictions?
- Far from perfect but good enough to be
useful clinically
- Chin and upper lip are good, lower lip area is
problematic

Advantages:
- Ease of multiple predictions
- Better communication
Disadvantages:
- Cost
- Limitations of the existing programs

Cast Prediction(Model Surgery)
- Dental cast version of cephalometric
prediction
- In its simplest form requires articulating the
casts by hand
- Generally is not required at this stage

Combining Surgery and
Orthodontics:
Who Does What, When?

Presurgical Orthodontics:
 It is neither necessary nor desirable to set
things up perfectly presurgically
 Goals:
- Align the teeth
- Establish anteroposterior and vertical position
of incisors
- Arch compatibility

 Selection of the Appliance:
- Should allow rigid stabilization
- Should include:
 Headgear tubes on upper molars
 Auxiliary tubes on upper and lower molars
 Lingual cleats or hooks on molars
- The less visible the appliance, the less impact
it has on social adjustment

 Lingual appliance is ill suited because:
- Impossible to use it to stabilize the jaws
- Difficulty in manipulation post-surgically
 Plastic and ceramic brackets
 Routine stainless steel twin or single brackets
with wings
 Both 18 and 22 slot bracket systems can be
used

 Bracket positioning is no different- tip the
brackets on teeth adjacent to the osteotomy
sites

 Alignment: The First Step in Treatment
- Achieved by tipping the crowns of the teeth
- Initial wires should be:
1. Round rather than rectangular
2. Undersized
3. Highly resilient

 Vertical Position of the Teeth: Leveling
the Arches
- When the mandible is moved forward or back
surgically, the vertical position of the lower
incisors will determine the face height
- The difference between leveling by extrusion
and leveling by intrusion is largely a
difference between continuous and
segmented arch wires

 Leveling within the segments

 Anteroposterior Incisor Position
- Will determine how much one jaw can be
moved relative to the other jaw
- Eliminate dental compensation
- Modest overtreatment of incisor position is
desirable

 Arch Compatibility:
- Expansion of constricted arch forms
- Heavy labial auxiliary to accentuate the effect
of main arch wire
- Orthodontic expansion should be limited to 2-
3mm per side
- Not more than half-cusp crossbite correction
should be left for post-surgical orthodontics

 Judging arch compatibility can be difficult
- In mandibular advancement, arch
compatibility can be judged clinically
- In maxillary advancement or mandibular
setback, compatibility can only be judged with
study casts

Final Surgical Planning and
Preparation:
 Presurgery Records
- Include panoramic and lateral cephalometric
radiographs, dental casts, photographs, PA
ceph in significant asymmetry
- An ideal time is about 2 weeks before surgery

 Cephalometric/ Computer Image
Predictions and Model Surgery:
- Cephalometric prediction must be done before
the model surgery
- When is it necessary to use a facebow transfer
to mount the casts on an articulator?
 If the condyles will be separated from the
dentition, there is no advantage in maintaining
this relationship during model surgery

- Model surgery serves two purposes:
1. Verification of planned movements
2. Fabrication of occlusal wafer splints
The best orthodontics and the most
skillful surgery can be negated by
poor presurgical planning

Model Surgery- Single Jaw
Surgery

Model Surgery - Double Jaw
Surgery
ImpressionsImpressions
Face-bow recordFace-bow record
Wax bite to recordWax bite to record
Pre surgical occlusionPre surgical occlusion

Casts mounted on semi-adjustable articulatorCasts mounted on semi-adjustable articulator

Mounting of maxillary cast with spacerMounting of maxillary cast with spacer

Blue plaster used for initial mountingBlue plaster used for initial mounting

Jig positioned in articulatorJig positioned in articulator

Maxillary cast stabilized with puttyMaxillary cast stabilized with putty

Initial mounting plaster removedInitial mounting plaster removed

Maxillary impactionMaxillary impaction

Measurement of amount of impactionMeasurement of amount of impaction

Simulation of mandibular autorotationSimulation of mandibular autorotation

Intermediate splintIntermediate splint

Mandible advanced to desired positionMandible advanced to desired position

Final splint fabricatedFinal splint fabricatedwww.indiandentalacademy.com

Final SplintFinal Splint

If the jig is not available, markings can be madeIf the jig is not available, markings can be made
on the caston the cast

 Common Problems at this Stage
1. Interferences from the second molar teeth:
arise from the absence of bands on lower
second molars or from the presence of
bands on the upper second molars

2. Incompatible canine widths: rarely a problem
in Class II patients; Class III patients cannot
simulate the postsurgical position

3. Lack of space for interdental osteotomy cuts:
4-5 mm of root separation is required
 Stabilizing Arch Wires and Splints
- Full dimension rectangular wire; at least
21x25 in a 22- slot appliance and 17x25 in a
18- slot appliance
- Attachments for maxillomandibular fixation
 Soldered brass spurs are preferred

 Crimp-on hooks are a tempting but
dangerous option:
1. May become loose
2. Act of crimping can distort the wire

Postsurgical Orthodontics
- When healing has reached the point of
satisfactory clinical stability
- First step is to remove the splint and
stabilizing arch wires.Price of removing the
splint alone is a centric relation- centric
occlusion discrepancy
- Insertion of working wires: 17x25 TMA, 19x25
TMA or 21x25 NiTi; 16 or 18 round steel

- Placement of light vertical elastics; should be
worn full time
- Elastics serve two purposes:
 Bring the teeth into solid occlusion
 Override the proprioceptive drive
- Transverse control is maintained by using a
heavy labial auxiliary wire placed in the
headgear tubes

- Second appointment: elastics can be omitted
while eating; Class II or Class III vector
- Third appointment: elastics only at night
- Observe patient for 4-6 weeks without
elastics before debonding
- Appliance removal: 4 months after returning
from the surgeon
 Retention:
- Care to prevent transverse relapse

Surgical Treatment

Principles of Surgical
Management:
 Advantages and Disadvantages of
Rigid Internal Fixation:
Advantages
1. Improved comfort and convenience:
Improved nutrition, speech, oral hygiene
2. Increased safety in the immediate
postoperative period: When excessive
haemorrhage or vomiting occurs, easy
access to the mouth and pharynx

3. More rapid bony healing
4. Ability to stabilize multiple bony segments:
Cases in which bony contact is insufficient for
direct wiring
5. Increased stability
6. Faster reduction of postoperative edema
7. Rehabilitation of muscles and TM joint

Disadvantages
1. Technical Difficulties: Plates must be
contoured so as to adapt passively.
Postsurgical adjustment of the segments is
difficult
2. Increased Costs
3. Possible Need for Plate Removal: Presence
of a palpable plate or screw, persistent
wound infection, metal sensitivity

4. Neurosensory Disturbances
5. Postoperative TM Joint Symptoms: Torquing,
distraction or rotation of the condylar
segments

Maxillary Surgery

Maxillary Surgery:
 Historical Development:
- Originated by Cheever in 1864 to gain access
to the nasopharynx
- In 1921, Herman Wassmund employed
maxillary osteotomy to correct dentofacial
deformity
- In 1934, Auxhausen related his experiences
with mobilization of the maxilla

- In 1952, Converse reported on maxillary
osteotomy
- Stoker and Epker offered encouraging results
- Wilmar, Obwegeser and Bell led American
surgeons to adopt totally maxillary osteotomy
procedures
- Allows the maxilla to be moved in all three
planes of space

LeFort I Osteotomy: Surgical
Techinque
 External reference mark is established at the
frontonasal area by inserting a Kirschner wire
or Steinmann pin

Maxillary Segmentation:
 To facilitate expansion or contraction, leveling
of the occlusal plane or space closure
 Paramidline sagittal osteotomy minimizes the
defect in the palate

 Stabilization and Fixation:
- With rigid fixation, maxillomandibular fixation
should always be removed and the occlusion
checked

 Nasal Airway Considerations:
 Adverse effect on nasal breathing because
space in the nasal cavity is reduced?
- Nasal resistance usually decreases
- When maxilla is moved up, alar base widens

- Nasal septum is repositioned without buckling
- Excessive flaring: suturing of transverse
nasalis muscle/ alar base cinch suture

Segmental Surgical Techniques:
Maxilla
 Historical Development:
Kole,
Murphey and
Walker,
Mohnac
Maxillary
Subapical
Osteotomy
Wassmund and Wunderer

 By 1980’s greater flexibility of LeFort I
osteotomy relegated maxillary subapical
osteotomy
 Indications for isolated posterior maxillary
subapical osteotomy:
- Reposition posterior dentoalveolar segments
- Isolated unilateral posterior crossbite

Surgical Techniques:
 Anterior Subapical Osteotomy
- Performed either in isolation or in conjunction
with mandibular anterior subapical osteotomy
- Most easily moved in a posterior and inferior
direction
- With difficulty, can be moved in a superior
direction
- Anterior movement is almost impossible

 Accomplished by using modifications of the
Wassmund or Wunderer techniques
 Wassmund Technique:

• Palatal soft tissue pedicle should be
inspected to make sure that it is not folded
on itself

 Wunderer Technique:

- With the Wunderer technique, a premolar can
be removed on one side and a molar on the
other
- If necessary, the segment can be divided in
the midline for expansion

 Posterior Maxillary Subapical
Osteotomy:
- For isolated unilateral posterior crossbite or
excessive eruption of posterior maxillary teeth

• When sufficient bone exists distal to the
terminal molar, vertical cuts made in this area

Mandibular Surgery

Historical Development:
 Prior to the 1950’s, body ostectomy for
shortening the mandible
 Ease of access and prevalence of missing
teeth
 Caldwell and Letterman’s paper on vertical
subcondylar osteotomy in 1954
 Surgical procedures to lengthen the
mandible: intraoral surgery popularized by
Trauner and Obwegeser

- Intraoral approach to vertical subcondylar
osteotomy
 Sagittal-Split Osteotomy: Surgical
Technique
- Originally described to American surgeons
by Obwegeser
• Advantages:
1. Great flexibility
2. Broad bony overlap

3. Minimal alteration in position of muscles and
TMJ
Technique:

 Transoral Vertical Ramus Osteotomy:
- Option for correction of mandibular
prognathism
- Used alone or in combination with sagittal-
split osteotomy on the opposite side
- Intraoral approach minimizes the
disadvantages of the extraoral approach

- Difficulties exist when large posterior
repositioning or asymmetry is present
- RIF techniques are difficult to apply
Technique
- Initial incision similar
- Periosteum reflected from the sigmoid notch
to inferior border

- Few mm of periosteum reflected on the
medial aspect

- Stabilization and Fixation:

- Patients are left in MMF for 4-6 weeks
 Extraoral Vertical Ramus Osteotomy:
- Most common procedure for setback
- Scars from skin incisions and damage to the
facial nerve
- Modifications have made advancement
possible

 Technique:
- Skin incision made below the angle and
posterior body of the mandible
- Facial nerve identified and protected
- Osteotomy: 5mm in front of posterior border
and behind the neurovascular bundle
- No fixation, direct wiring, screws or bone
plates

 Combined Vertical Ramus and Sagittal
Osteotomies:
- When large advancements are needed
- Skin incision extended as far forward as the
mental foramen

 Body Ostectomy:
- First procedure performed in orthognathic
surgery
- Special indications today: narrow the dental
arch; when deformity is primarily an
elongation of the body

 Inferior alveolar neurovascular bundle
decompression

 Inferior Border Osteotomy:
- To reposition the chin in all three planes
- Decompression usually not necessary

 Anterior Subapical Osteotomy:
- To close anterior open bite, to depress
elevated anterior dentoalveolar segment, to
advance or retrude
- Combined with anterior maxillary subapical
osteotomy

 Technique:

- Neurovascular decompression may or may
not be required

 Total Subapical Osteotomy:
- Major technical problem centers on
management of neurovascular bundle
- Indicated when deformity is confined to the
dentoalveolar aspect

- Tangential cut extends from alveolar crest
into residual mandibular canal

Mandibular Deficiency

 Diagnostic Characteristics:
- Chin and lower lip deficiency
- Everted lower lip
- Increased overjet
- Anterior deep bite
- Excessive Curve of Spee
- More severe maxillary than mandibular
incisor crowding

 In short face
individuals-
deficiency at the
lower lip more than
at the chin

- Interaction between the vertical and AP
positions of the lower incisors and the chin

 Anterior deep bite causes two functional
problems:
1. Irritation of gingival tissues
2. Tendency of TM joint clicking
The deep bite may predispose to TM joint
problems but is unlikely to be their sole cause

 Surgical Approach:
- In patients with short face height, the chin
needs to be moved down
- Difficult to move the chin down nonsurgically
by rotating the mandible at the condyles
- Half or more of the rotation created is lost in
retention

 Subapical Osteotomy vs Ramus
Osteotomy:

 Indication for subapical osteotomy: Prominent
chin relative to the dentition; face height only
slightly reduced
 Presurgical Orthodontics:
 Goals:
1. Align irregular teeth
2. Establish AP and vertical incisor position
3. Establish compatible arch forms

 Orthodontic Approach
- Need to properly position the incisors in both
the vertical and AP planes of space
- Extraction decision
- Tendency towards posterior crossbite when
mandible is advanced more than a few mm

 Levelling:
- Done by post surgical extrusion
- Arch wires are flat in the upper arch and with
an accentuated curve in the lower arch
- If intrusion is required- segmented arches
- Extraction spaces should be completely
closed
- Culmination with placement of full dimension
rectangular wires

 Final Presurgical Planning:
- Presurgical records to be taken
- When ramus surgery alone is planned, no
need to mount
- No further tooth movement should occur

 Guidelines for Positioning Casts for
Splint Fabrication:
1. Keep things symmetrical in the transverse
plane
2. Bring incisors in an ideal relationship, not
overcorrecting
3. Keep skeletal midlines correct
4. If wire osteosynthesis/MMF, bring incisors
in an edge-to-edge relation

 Surgery:
- BSSO
- Remove 3rd
molars: erupted or impacted
 Teeth are in the surgical site
 Best site for lag or position screws
- BSSO may be combined with inferior border
osteotomy

- Lengthening the inferior border is a
predictable procedure
- AP chin reduction is not esthetically
predictable
- With large advancements, extraoral ramus
procedure may be indicated
- Maxillary surgery:
 To widen the maxilla
 To bring the maxilla down

 Postsurgical Orthodontics:
- Splint should not be removed till the patient is
ready for orthodontics
- Mandibular advancement patients to be
levelled postsurgically make a “three-point
landing” occlusally
- Orthodontic treatment can resume 3-4 weeks
with RIF and 6 weeks with wire
osteosynthesis/ MMF

Long Face Problems

 Diagnostic Characteristics:
- Excessive lower facial height: It is impossible
for a long face patient not to have a problem
in the AP plane of space
- Lip incompetence: Unfortunately, lip
incompetence by itself is misleading
- A tendency towards an anterior open bite:
1/3rd
may have normal or even deep bite

- A tendency towards mandibular deficiency
and Class II malocclusion
- A tendency towards more crowding of the
lower than the upper incisors
- A tendency toward a narrow maxilla and
posterior crossbite

 Cephalometrically,
long face patients
have the following:
- Rotation of the
palatal plane down
posteriorly

- Excessive eruption of maxillary posterior
teeth
- Rotation of the mandible down and back
- Excessive eruption of the mandibular and
maxillary incisors

 Treatment Planning
 Adolescents with Questionable Growth
Potential:
- Most long face patients have a receding chin
and a Class II malocclusion
- A camouflage treatment plan is ineffective
- Incisors elongate, nasolabial angle will
increase, effects of Class II elastics

- If extraction for camouflage is to be avoided,
is there any orthodontic alternative for the
long face adolescent?
- Growth modification after the adolescent
growth spurt is more a theoretical than actual
possibility

- Anterior open bite in adolescents(or adults)
often can be corrected with orthodontic
treatment
- Open bite correction almost totally occurs by
elongation of the incisors
- Elongation of the lower incisors is both more
stable and more esthetic than elongation of
the upper incisors

 Lower border osteotomy in borderline cases
 Relaxing the lower lip also improves the
stability of the lower incisors

 Adults with Little or No Growth
Potential
 A patient who has a genuine long face
problem and who refuses surgical
correction is better left untreated
Surgical Approach: Three options
1. Superior repositioning of the maxilla or at
least the posterior part

2. Mandibular surgery to bring the lower jaw
forward and upward
3. Inferior border osteotomy
Guideline:
In patients whose face height should be
reduced, maxillary surgery is the primary
procedure

 Maxilla is the focus of treatment for 2
reasons:
1. It nearly always has excess vertical
development
2. Moving the maxilla up produces a stable
correction
 Class I rotated to Class II
 Class III rotated to Class I

 If mandible is small, ramus osteotomy is
indicated
 Dentoalveolar segments can be created:
- Two segments for widening of the maxilla
- Three segments for moving the posterior
segment up

 Presurgical Orthodontics
1. Incisions tend to stress the gingival
attachments; place grafts at least 2-3 months
before surgery
2. Patients with anterior open bite and vertical
steps in the arch

It is a mistake to level the upper arch
presurgically because this produces a relapse
tendency

3. Orthodontic or surgical expansion
 Final Presurgical Planning
- Two critical elements:
1. How far the maxilla is moved up
2. If there would be residual overjet with
straight vertical movement

1. How far the maxilla is moved up:
- Moving the maxilla too far up is harmful
- It is better to leave 4 mm of lip separation
- Associated soft tissue changes accentuate
this effect
2. Residual overjet with vertical movement:
- Moving the maxilla back is bad for esthetics

 Patients who posture
the mandible forward
are a problem

 Postsurgical Orthodontics
- Maintaining transverse maxillary expansion
achieved at surgery
- Patients who had maxillary expansion should
wear their retainer diligently

Class III Problems

Surgical Options:
 Maxillary versus Mandibular Surgery:
- Setting the chin back was the original
orthognathic surgical procedure
- Although maxillary osteotomies were
introduced in the 1960’s mandibular setback
remained till the 1980’s
- Why did this change occur?

- When the mandible is
set back, the volume
of the oral cavity is
reduced
- Undesirable changes
in throat form
accompany
mandibular setback

- When maxillary deficiency is part of the Class
III problem

- In severely affected individuals, maxillary
deficiency is three dimensional
 Treatment of transverse and vertical
deficiency can be problematic

 LeFort I osteotomy plus lower border
osteotomy

 Timing of Orthognathic Surgery in
Class III Patients:
- Can be done early to control social handicaps
but late growth can lead to relapse
- If Class III problem is due to maxillary
deficiency, surgery can be done earlier

 Serial cephalometric radiographs at yearly
intervals

 Orthodontic Preparation for Surgery:
- Class III patients have two types of dental
compensations
1. Extraction of maxillary first premolars is often
required
- Should the orthodontist totally close the
extraction spaces prior to surgery?
2. Moving the lower incisors forward provides
better tooth-lip balance

- Extraction of mandibular second premolars
3. If there is not a posterior crossbite before
surgery, there will be afterward
- Check for arch compatibility
4. Should surgically assisted RPA be done for
transverse maxillary deficiency?
- Reserved for the patient who needs large
expansion (10mm or more)

5. Should model surgery and splint fabrication
build in overcorrection for postsurgical
relapse?
- Under no circumstances should the dental
casts be placed with more than 2-3mm of
excess overjet

 Special Considerations at Surgery:
- Stabilization after a segmental osteotomy
must be carefully managed
- Downward movement of the maxilla is also a
stabilization problem

- Controlling the inclination of the ramus during
mandibular setback

 Postsurgical Orthodontics:
- Labial wire to maintain transverse expansion
- Elastics in a triangular pattern with a Class III
component
- Retention: If mild continuing relapse towards
Class III, light Class III elastics at night

Special Considerations in Cleft
Palate Patients:
- Most cleft palate patients have a tendency
towards Class III malocclusion
- Almost never in a cleft palate patient is it a
good idea to attempt Class III camouflage
- Retrusive upper incisors are not an argument
for compensatory extraction in the lower arch

 Posterior crossbite in cleft patients:
1. Surgical intervention has produced tight
palatal tissue
2. No equivalent of a mid palatal suture

Orthognathic Surgery in Cleft
Patients:
- Almost always involves moving the maxilla
forward
- Two limiting factors in surgery for cleft
patients:
1. Residual scarring from previous surgeries
2. Risk of producing velopharyngeal
incompetence

- Both scarring and speech effects limit the
amount of maxillary advancement possible
 Surgical Orthodontic Coordination:
- Timing of orthognathic surgery is critical
- Difference in orthodontic preparation
- Moderate overcorrection of anterior crossbite
is desirable

Dentofacial Asymmetry

 Perfect facial symmetry is exceedingly rare
 All normal faces have a degree of
asymmetry- use of composite photographs

 Special Considerations in Diagnosis
and Treatment Planning:
- Careful history taking
- Obtaining a PA cephalogram
- Care while taking lateral
cephalograms

 Use of stereolithographic models for planning
surgery

 Timing of Treatment:
- Progressive deformity vs stable deformity
 Common conditions causing asymmetry:
1. Hemifacial microsomia
2. Condylar fractures
3. Hemimandibular hypertrophy

 In preadolescent children, hemifacial
microsomia and condylar fractures cause
severe asymmetry
 Both primarily affect the mandible, maxilla is
affected secondarily
 Basic difference, in hemifacial microsomia
both hard and soft tissue elements are
missing

 Early treatment: use
of hybrid functional
appliances
 Should be continued
only as long as it is
effective

Hemifacial Microsomia:
- Grade I: Soft tissues and mandible are
deficient on the affected side
- Grade II: Condyle, ramus and glenoid fossa
may be present or absent
- Grade III: Complete absence of condyle and
ramus

- Children with grade I
and mild grade II
may respond
favorably to
functional appliance
therapy

 Surgical Correction:
- Three stages of surgical intervention:
Converse; Vagervik, Hoffman and Kaban
 Surgical phase I: tissue augmentation.
- Replace missing skeletal elements and
augment severely deficient areas
- If a patient has a ramus and condyle, it is
better to accept this articulation

- Two approaches to augmentation:
1. Inverted L osteotomy
2. Distraction osteogenesis

- Functional appliance in the immediate
postsurgical period to control eruption of teeth
and improve the cant of maxilla
 Surgical phase 2: jaw relationships
- After the adolescent growth spurt, should
address orthognathic concerns
- Inferior border osteotomy; onlay bone grafts
- Less likelihood of maxillary surgery

 Surgical phase 3: contour modification
- To enhance the contour of the skeleton and
soft tissues
- Soft tissue augmentation with fat
- Ear reconstruction

 Condylar Fractures: Management of
Post- Traumatic Asymmetry
- More growth on the normal than the affected
side
- Old condylar fracture or mild hemifacial
microsomia?
- Response to a functional appliance should be
evaluated

 Purpose of surgery is not to correct the
asymmetry
 Remove TM Joint restrictions
 Surgical reconstruction:
1. Use local tissue
2. Costochondral graft
- In children costochondral graft does not
work well

 Hemimandibular Hypertrophy:
- Formerly called condylar hyperplasia
- Usually becomes apparent after the
adolescent growth spurt
- Tends to be self limiting
 Clinical Management:
- If asymmetric stops, delay the surgery
- If severe enough, remove the growth site

- Two modes of presentation:
1. Head remains normal in size, neck
increases

2. Condylar head enlarges

 Technetium bone scan

 Surgical options:
1. Excision of bone at the head of the condyle
2. Removing the condyle and condylar
process

- Sagittal split osteotomy on the unaffected
side
- Maxillary surgery if maxilla is canted

Asymmetry in Adults:
 Treatment Planning Considerations:
- Extent to which surgery will be used to correct
the deformity at its point of origin
- Nose may deviate in the same direction as
the chin: moving the jaw magnifies the
deviation of the nose

- Goal of presurgical orthodontics is to
remove dental compensations
- Two approaches to transverse
decompensation:
1. Asymmetric extraction
2. Asymmetric elastics
- Correction of canted maxilla by LeFort I
osteotomy

- Asymmetric elastics in patients who have
undergone surgery
- Box elastics with Class II component on one
side and Class III component on the other

References:
 Contemporary Treatment of Dentofacial
Deformity
- William R. Proffit, Raymond P. White Jr., David M.
Sarver
 Contemporary Orthodontics
- William R. Proffit, Henry W. Fields Jr.
 Orthodontics: Current Principles and
Techniques
- Thomas M. Graber, Robert L. Vanarsdall Jr.

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