Surgical orthodontic treatment

SURGICAL
ORTHODONTIC
TREATMENT
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Contents
 Introduction
 History
 Role of Orthodontist
 Indications of Orthognathic Surgery
 Diagnosis and Treatment Planning
 Clinical evaluation
 Cephalometric evaluation
 Growth Modification for Skeletal changes in
Adolescents :- What works?

Contents
 Limitations of Growth Modification
 Pre-surgical orthodontics
 Compensation
 Decompensation
 Model Surgery
 Surgical Procedures
 Involving Maxilla
 Involving Mandible
 Soft tissue changes following surgical procedures
 Conclusion

Introduction
 Malocclusion can be due to many possible
reasons but they can be treated by:-
1. Modification of growth
2. Orthodontic camouflage which produces a
dental compensation for the skeletal
compensation.
3. Surgical repositioning of the jaws and/or
dentoalveolar segments
Contemporary Treatment of Dentofacial Deformity- Sarver

HISTORY
 SURGICAL TREATMENT FOR
MANDIBULAR PROGNATHISM STARTED
IN EARLY 19th
CENTURY.
 In 1959, Trauner and obwegeser introduced
sagittal split osteotomy as the beginning of a
new era of orthognathic surgery.

1960
 American surgeons modify the technique for
maxillary surgery that has been developed in
europe
 Epker, bell and wolford developed lefort-1
maxillary downward fracture ,so that we can
keep the maxilla stable in all 3 planes of
spaces

1980 - 1990
 By 1980 progress has reached such an
extent to reposition either or both the jaws to
move chin in all 3 planes of spaces.
 Rigid internal fixation made it possible for
comfort and better immobilization was
achieved.

DIFFERENT APPROACHES IN
ORTHODONTICS
 Envelope of discrepancy shows how much of
change can be produced by various
treatment modalities.
3 5 25
2
5
15
5101
2
4
6
10
7 12 15
2
5
15
2510
4
6
10

INDICATIONS
 Severe skeletal classii &classiii cases
 Skeletal open bite and deep bite cases
 Deep over bite in non growing individuals
 Extreme vertical excess or deficiency in
maxilla or mandible
 Severe dentoalveolar problem
 Extemely compromised periodontal situation
 Skeletal asymmetry

ROLE OF ORTHODONTIST
 ORTHODONTISTS HAVE MOST EXTENSIVE
KNOWLEDGE ABOUT GROWTH &
DEVELOPMENT THAN ANY OTHER
PROFESSIONALS
 AS ORTHOGNATHIC SURGERY HAS BECOME
MORE REFINED & LESS TRAUMATIC
PROCEDURE , IT RAPIDLY BECAME A
REASONABLE TRETMENT OPTION

 THE ESTHETIC & FUNTIONAL GOALS FOR
GROWING Pts SHOULD BE THE SAME AS
THEY ARE FOR OUR ADULT Pts
 IN CONTEMPORARY ORTHODONTIC
PRACTICE THE DIFFERENCE IN
ESTHETIC PLANNING IN ADOLECENT &
ADULT Pt IS FAIRLY SIMPLE

 IF SKELETAL CHANGES ARE DESIRED
THE GROWING Pt RECEIVES GROWTH
MODIFICATION
 IN ADULT BECAUSE THE GROWTH IS NO
LONGER AVAILABLE , SURGICAL
MODIFICATION OF JAWS IS MORE
STRONGLY CONSIDERED

GROWTH MODIFICATIONS FOR SKELETAL
CHANGES IN THE ADOLESCENT : WHAT WORKS ?
 MANDIBULAR DEFECIENCY CAN BE
TREATED BY
A. REDIRECTION OF SKETAL GROWTH
VECTORS WITH HEAD GEAR
B. FUNTIONAL APPLIANCES
C. COMBINATION OF ABOVE

MAXILLARY HORIZANTAL
DEFECIENCY (ANTEROPOSTERIORLY)
 TREATMENT BY RECENT
DEVELOPMENTS IN MAXILLARY
PROTRACTION & NON SURGICAL
ADVANCEMENT OF MAXILLA
(Moderate severity)

VERTICAL MAXILLARY EXCESS
 HIGH PULL HEAD GEAR
 BITE BLOCKS OF FUNCTIONAL
APPLIANCES AND VERTICALLY
DIRECTED CHIN CUPS HAVE A
DIMINISHING EFFECT ON VERTICAL
MAXILLARY EXCESS

HORIZANTAL MAXILLARY EXCESS
 RETARDATION OF ANTEROPOSTERIOR
GROWTH WITH HEAD GEAR
 EXTRACTION OF PREMOLARS
(CAMOUFLAGE)

AREAS OF SKEKETAL
DISCRIPANCY WHICH CAN NOT BE
EASILY IMPROVED BY GROWTH
MODIFICATION

1.MANDIBULAR PROGNATHISM
IN PAST ATTEMPS WERE MADE TO RETARD THE
EXCESS GROWTH OF THE MANDIBLE THROUGH
EXTRA ORAL FORCES APPLIED VIA CHIN CUP.
 BECAUSE THE MANDIBLE GROWS BY APPOSITION
OF BONE AT THE CONDYLE & ALONG ITS FREE
POSTERIOR BORDER THIS METHOD IS NOT
SUCCESSFUL AS THE USE OF EXTRA ORAL FORCE
TO THE MAXILLA www.indiandentalacademy.com

 THE CHIN CUP TREATMENT IS
FAVOURABLE IN SHORT LAFH , BECAUSE
ITS APPLICATION CAN RESULT IN
DOWNWARD & BACKWARD ROTATION OF
THE MANDIBLE
 THIS CUP IS CONTRA INDICATED IN
LONG FACE CL-III Pts.

2. VERTICAL MAXILLARY GROWTH
DEFECIENCY
3.CHIN DEFECIENCY

DIAGNOSIS AND TREATMENT
PLANNING

 DIAGNOSIS AND TREATMENT PLANNING
APPROACHES FOR PATIENTS WITH
DENTOFACIAL DEFORMITY ARE
BASICALLY THE SAME AS FOR PATIENTS
WITH LESS SEVERE DISTORTIONS OF
DENTAL AND FACIAL PROPORTIONS

 THERE IS NO USE OF USING A SINGLE
DIAGNOSTIC TOOL TO IMPLICATE
APPROPRIATE TREATMENT AS EDWARD
ANGLE ONCE HOPED
 UNTILL RECENTLY HARD TISSUES OF THE
FACIAL SKELETON WERE THE FOCUS OF
DIAGNOSIS AND TREATMENT PLANNING

 IT IS NOW CLEAR
THAT THE SOFT
TISSUES ARE THE
LIMITING FACTOR IN
THE CHANGES THAT
CAN BE PRODUCED
IN TREATMENT AND
OBTAINING
APPROPRIATE SOFT
TISSUE
PROPORTIONS IS
THE PRIMARY GOAL
OF TREATMENT

SOFT TISSUE PARADIGM
 GROWTH & MATURATION OF FACIAL
SOFT TISSUES
 LIPS
 NOSE
 CHIN

LIPS
 THE Ht OF CENTER PART OF UPPER LIP TRAILS
BEHIND THE VERTICAL Ht OF THE LOWER FACE
IN CHILDHOOD & THEN CATCHES UP DURING &
AFTER ADOLESCENCE.
 LIP INCOMPETENCE IS COMMON IN CHILDREN
 WHAT LOOKS LIKE INCOMPETENT LIPS IN
CHILDHOOD OR EARLY ADOLESCENCE IS
MERELY A REFLECTION OF INCOMPLETE SOFT
TISSUE GROWTH

 FEMALES : UPPER LIP TILL 14
LOWER LIP CONTINUES TO
GROW UP TO THE AGE OF 16
 MALES : GROWTH OF BOTH UPPER &
LOWER LIP CONTINUES INTO LATE
TEENS
LIP HIEGHT

 LIP THICKNESS IS MAXIMUM DURING THE
CONCLUSION OF ADOLESCENT GROWTH
SPURT & THEN DECREASES DURING
LATE TEENS.

NOSE
 BOTH MALES & FEMALES SHOW MORE
GROWTH IN VERTICAL ht THAN
ANTEROPOSTERIOR PROJECTION OF
NOSE BUT DOWNWARD GROWTH IS
GREATER IN MALES
 BOYS HAVE AN ADOLESCENT GROWTH
SPURT IN NOSE LENGTH WHERE AS
OFTEN GIRLS DO NOT

 A DORSAL HUMP IN THE NOSE
DEVELOPS WHEN CI-II MALOCCLUSION IS
PRESENT & IS MORE PRONOUNCED IN
BOYS
 AMJ ORTHD 56:403-414,1969

CHIN
 BOTH SEXES HAVE SIMILAR (13.3mm)
SOFT TISSUE THICKNESS AT AGE 17
 THE SIZE OF CORPUS & THICKNESS OF
BONY SYMPHYSIS ARE SAME AT 7
YEARS . GROWTH CURVES FOR BOTH
THE SEXES ARE PARALLEL TO EACH
OTHER UNTILL AGE 15 AFTER WHICH
MALES HAVE LARGER CHANGES

 THE INCRESED CHIN PROJECTION SEEN IN
MALES DURING GROWTH IS DUE TO THE
UNDERLYING SKELETAL CHANGES IN LATE
ADOLESCENCE THAN SOFT TISSUE CHANGES
 PERHAPS THERE IS NO REASON TO EXPECT
THAT THE AMOUNT OF SOFT TISSUE THAT
COVERS THE BONY CHIN WILL CHANGE
SIGNIFICANTLY DURING GROWTH

Methods for evaluation of smile
 The major goals of orthodontics
and/orthognathic surgery is to enhance anterior
tooth display during speech and smiling.

 A balanced smile is achieved by appropriate
positioning the teeth and gingiva in the area
that is displayed by lip animation during
smiling (the dynamic display zone)

 Appropriate positioning entails not only the
three planes of space (vertical, lateral, and
anteroposterior) but also the orientation of the
occlusal plane transversely and sagittally.

Types of the smile
 Posed smile :
also called as social
smile,

Spontaneous
smile :has been
referred to as the
enjoyment smile.
 The difference between social and
enjoyment smile is not the activity of
orbicularis oris musculature but of orbicularis
oculi. www.indiandentalacademy.com

 In the enjoyment smile, there is a crinkling
around the eyes that cannot be duplicated with a
social smile.

 An unposed smile is involuntary and is
induced by joy or mirth.
 Where as posed smile are of two types
 Strained
 Unstrained.

SMILE ANALYSIS

1. THE AMOUNT OF INCISOR AND GINGIVAL
DISPLAY
 As a general guideline, the elevation of the
lip for the posed smile should stop at or near
the gingival margins of the maxillary incisors.
Some gingival display is certainly acceptable,
and in many cases, even esthetic and
youthful appearing.

 Conversely, lip
elevation that does not
reach the gingival
margin (i.e., less than
100% incisor show on
smile) is not as
attractive as complete
tooth display or even
some gingival display.

 Males show less of the upper incisors and
more of the lower incisors than females, at
rest and on smile. It is also a characteristic of
aging to show less of the upper incisors at
rest and on smile, so that, to a degree, more
tooth display gives a more feminine and
youthful smile.

THE TRANSVERSE DIMENSION OF
SMILE
 This characteristic is
referred to in terms of
“broadness the smile"
and the presence and
amount of "buccal
corridor” also referred to
by some orthodontists
as "negative space," to
be eliminated by
transverse expansion of
the maxilla.

 Prosthodontic smile: It is referred as
unrealistic "denture smile" due to lack of
buccal corridors.

 This smile feature has been thought of
primarily in terms of maxillary width, there is
evidence that the corridors are also heavily
influenced by the anteroposterior position of
the maxilla relative to the lip drape. This
means that moving the maxilla forward also
reduces the size of the buccal corridors and
decreases negative space.

THE SMILE ARC
 The ideal smile arc has
the curvature of the
maxillary incisal edges
parallel to the curvature
of the lower lip upon
smile, and the term
consonant is used to
describe this parallel
relationship.

 A nonconsonant, or flat,
smile arc is
characterized by the
maxillary incisal
curvature being flatter
than the curvature of
the lower lip on smile.

ASSESSMENT OF FACIAL SOFT
TISSUE: FRONTAL VIEW
VERTICAL FACIAL
PROPORTIONS

 The ideal face in both
males and females is
vertically divided into
equal thirds by
horizontal lines at the
hairline, the nasal base,
and the menton

 In the middle third, philtrum height is
important, especially in its relationships with
the upper incisor and commissures of the
mouth. Commissure height is normally is no
more than 2 to 3 mm greater than the
philtrum height in adults, but in adolescents
the philtrum height may be several
millimeters shorter.

 A short philtrum in
adults results in an
unaesthetic maxillary lip
line, which makes
resting posture
resemble a frown.

 The base of the nose has a "gull in flight"
contour. The nares should be barely visible
when the head is in natural head position,
and the columella should be slight lower than
and parallel to the alae when viewed in any
direction.

 The contour of the alae
from the base of the
nose to its tip should be
well defined to form a
"scroll".

 In the ideal lower third of the face, the upper
lip comprises the upper one third and the
lower lip and chin make up the lower two
thirds.

 Excessive lower face height can be caused
by a number of things, but two principal
possibilities should be kept in mind:

 excessive vertical
development of
maxilla, which causes
the mandible to rotate
down and back,
 And excessive vertical
development at the
chin.

Tooth-lip relationships
 In adolescents 3 to 4 mm of the maxillary
incisor should be displayed at rest, and the
entire clinical crown (with some gingiva)
should be seen on smiling.

 In general, at rest males show less upper
incisor and more lower incisor, whereas
females show more upper incisor and less
lower incisor.

EXCESSIVE TOOTH DISPLAYS
 Excessive incisor display is judged better at
rest than on smile, simply because lip
elevation on smiling is so variable.

 If the exposure at rest is
normal, even if
considerable amount of
gingival display occurs
on smiling, this should
be considered normal
for that individual.

Excessive tooth display
maybe result of both hard
tissue and soft tissue
factors, such as
 Short philtrum height
 Vertical maxillary
excess
 Excessive crown height
 Lingually tipped
maxillary incisors.

Inadequate incisor display
 Excessive philtrum
height
 Vertical maxillary
deficiency
 Inadequate crown
height (loss of tooth
structure)
 Flared maxillary
incisors.

Transverse facial and dental
proportions
 The “rule of fifths" describes the ideal
transverse relationships of the face; the face
is divided sagittally into five symmetric and
equal parts, and each of the segments should
be the width of one eye.
 The rule emphasizes the total dentofacial
area and is based on proportional
relationships, not absolute measurements.

The central fifth of the face
 The middle fifth of the face is delineated by
the inner canthus of the eyes.
 A line from the inner canthus should be
coincident with the ala of the base of the
nose; that is, the width of the alar base of the
nose should equal the inner canthal distance

 If the inner canthal
distance is smaller than
an eye width, the nose
should be slightly wider.

The medial fifths of the face
 For ideal transverse
proportionality of the
face, the width of the
mouth and the
interpupillary distance
should be the same.

 A line from the outer
canthus of the eyes
should be coincident
with the gonial angles of
the mandible; that is,
the bigonial width
should equal the outer
canthal distance.

The outer fifths of the face
 The outer fifths of the face are measured
from the outer canthus of the eye and gonial
angles to the helix of the ear. This dimension
is largely composed of the width of the ear.

Soft tissue proportions: profile
view.
 The prominent part of the forehead (glabella)
should be approximately the same as the
base of the nose, and the forehead should
slope gently posteriorly.
 The radix (the depth of the concavity at the
base of the forehead) should be prominent to
obscure the eyelash on the opposite side.

 The bridge of the nose (nasal dorsum) should then
be a straight line from the base of the radix to the
nasal tip cartilage, and there should be a slight
prominence of the tip relative to the bridge.
 The lips should be slightly everted relative to their
base, with several millimeters of vermilion border
displayed, and the upper lip should be slightly
anterior to the lower lip.

 The labiomental sulcus should form a shallow
S curve, with the upper and lower portions
similarly shaped. The prominence of the chin
should be slightly less than the prominence of
the lower lip, and the angle between the lower
lip, chin, and deepest point along the chin-
neck contour should be approximately 90
degrees

 Ideal male profile
 An ideal male profile differs from the female
in several ways: greater forehead
prominence, deeper radix, more projection of
the nasal dorsum and lower nasal tip, flatter
lips with less vermilion display, upper lip even
with lower lip, and greater chin prominence.

Burstone's Hard Tissue
Analysis (COGS)
Burstone, Randal, Legan, Murphy &
Norton
(1978)

Purpose
 To be able to analyse variation in facial bone
as well as the dentition in relation to the jaws.
 Analysis for patients requiring orthognathic
surgery

Planes
 Uses constructed true horizontal as a reference
plane.
 Occlusal plane is drawn form the buccal groove of
both permanent molars through a point 1mm apical
to the central incisors of each respective jaw base.
 Mandibular plane is drawn from Go-Gn.
 The nasal floor plane is the palatal plane.
Burstone article J oral surg 1978

Construction of horizontal plane
Length of cranial base
N-A-Pg angle
N-A
N-pog

Vertical Skeletal
N-ANS
ANS-Gn
PNS-N
Mandibular plane angle

Vertical Dental Measurements
Lower molar to Mand. plane
Lower incisor to Mand plane
Upper molar to Nasal Floor
Upper incisor to Nasal Floor

Maxillary and Mandibular measurements
ANS-PNS
Ar-Go
Go-Pg
Gonial Angle and Chin
Prominence
Ar-Go-Gn
B-Pg

Dental Angular Measurements
Upper Incisor – Nasal Floor angle
Lower Incisor – Mandibular Plane Angle
Horizontal to Occ. Plane angle

A-B parallel to Occ. plane

Burstone’s Soft Tissue
Analysis
Legan & Burstone
(1980)

Purpose
 A soft tissue cephalometric analysis designed
for the patient who requires surgical
orthodontic care was developed to
complement a previously reported
dentoskeletal measurement.
Burstone article J oral Surg. 1980

Planes
 The SN plane is the plane of reference when
converted to the true horizontal.

Facial Convexity
Angle
G-Sn-Pg
angle=12 °
Maxillary and
Mandibular
Prognathism
G-Sn=6mm
G-Pg=0mm

Vertical Height
Ratio=1:1
G - Sn
Sn - Me
Nasolabial
Angle=102 °

Lower face Throat angle and Lower
Vertical Height- Depth ratio=1:1.2
Sn-Gn
Gn-C
Sn-Gn-C
angle=100 °
Vertical Lip to Chin Ratio=1:2
Sn-Stms
Stmi- Me

Interlabial Gap=2mm
Mentolabial
Sulcus=4mm
Upper lip protrusion=3mm
Lower lip
protrusion=2mm

Maxillary Incisor Exposure=2mm
Stms-Upper incisor

Grummons Analysis
Grummons & Kappeyne
(1987)

Purpose
 To find any frontal skeletal assymetry.
 To study the frontal VTO
 To evaluate tooth eruption with segmental
TMJ splint therapy.
 To evaluate improvements in facial or dental
proportions.

Planes
 Plane of reference is drawn from Crista Galli
to the ANS to the chin and will be
perpendicular to the Z plane.
 Selected because it closely follows the visual
plane formed between subnasale and
midpoints between the eyes and eyebrows.
Grummons article JCO 1987

 The first horizontal plane connects the medial
aspects of the zygomaticofrontal sutures.
 The second horizontal plane connects the center of
the zygomatic arches.
 The third horizontal plane connects the jugal
processes.
 A fourth horizontal plane runs through the menton
and is parallel to the first plane.
Grummons article JCO 1987

Zygomaticofrontal sutural plane
Zygomatic arch plane
Jugal plane
Z plane through menton
Mandibular morphology
Volumetric comparison

Maxillo mandibular comparison of
assymetry

Linear Asymmetry Assessment
Co-MSR
NC-MSR
J-MSR
Ag-MSR
Me-MSR

Maxillo mandibular relations
J perpendicular to 1st
molar
Ag to Ag
ANS-Me

Frontal Vertical Proportion Analysis
Upper facial ratio
Lower facial ratio
Maxillary ratio
Total Maxillary ratio
Mandibular ratio
Total Mandibular ratio
Maxillomandibular ratiowww.indiandentalacademy.com

PRESURGICAL
ORTHODONTICS
 COMPENSATION
 DECOMPENSATION

Compensation
 In cases of severe jaw imbalances, the
teeth are inclined in such a way as to
partially offset the discrepancies.

 For e.g., the lower
anteriors may be
upright or retroclined in
a case of mandibular
prognathism and
proclined in mandibular
retrognathism.

 This is nature’s mechanism to compensate
for the jaw imbalance by proclining or
retroclining the teeth i.e., as a compensation
for the jaw discrepancy.

DECOMPENSATION
 Presurgical orthodontics is aimed at
removing this natural compensation i.e.,
decompensation.

 In mandibular prognathism for e.g., the
retroclined incisors should be brought into
the ideal axial inclination by proclining them.
 In mandibular retrognathism, the proclined
teeth are brought back.
 Often, teeth are extracted for
decompensation.

 Decompensation makes the maxillo-
mandibular dental relation temporarily
worse. Hence it is sometimes called
“Reverse Orthodontics”.

Extraction Pattern
 The extraction pattern for decompensation
is different from what we do normally in
camouflage treatment.
 In camouflage, extraction spaces are
closed for dental compensation but in
orthognathic case, extraction spaces are
used to align the teeth on their respective
jaw bases.

 Often the extraction
pattern for Class II case
is, 5|5 and 4T4. Lower
extraction space is used
to retract the
compensated flared
incisors.

 Whereas in a skeletal
class III case
extraction of 4|4 and
5T5 is required for
correction of proclined
upper incisors which
is usually present.

 The common belief that Class II elastics are
used in class II skeletal pattern, is no more a
valid approach if mandibular advancement is
planned.
 Instead Class III elastics should be used.

 Similarly opposite
movements are
frequently required in
skeletal Class III
surgical patients.

Root Divergence in Segmental
Osteotomy
 When extractions are indicated, the teeth to
be moved should help both, in eliminating
the crowding and providing an osteotomy
site.

 Analysis of the size, shape and angulation
of the roots of the teeth adjacent to potential
osteotomy cuts is a key step in the selection
of the sites, particularly if no extractions are
to be performed

Vertical Plane
 Before surgery, the orthodontist must
establish not only the ideal anteroposterior
and transverse positions but also the
vertical position of the teeth.
 For instance, in a patient who will have only
a mandibular ramus osteotomy, the vertical
position of the incisor teeth determine the
post surgical facial height.

 This in turn will determine whether leveling
of an excessive curve of Spee should be
done either by intrusion of the incisors or
elongation of the posterior teeth.

Segmental Osteotomy
 It is neither necessary nor desirable to level
the entire arch in a patient with vertical
discrepancy (e.g. open-bite or deep-bite),
that is being prepared for a segmental
osteotomy.

 In these cases the leveling is done only
within each segment, either using
segmental NiTi wire or bond the anterior
and posterior brackets at different heights.

Why is Presurgical
Decompensation So Important ?
 To position the teeth in an ideal axial
inclination with respect to their respective
jaws.
 To optimize the magnitude of the surgical
advancement or setback.
 For better esthetics, stability and function.
 If malpositioned anterior teeth are not
corrected they hinder the repositioning of the
jaws at the time of surgery.

SURGICAL PROGEDURES
 INVOLVING MAXILLA
 INVOLVING MANDIBLE
 Combination of both

SURGICAL PROCEDURES
INVOLVING MAXILLA
 LEFORT 1 OSTEOTOMY
 ANTERIOR MAXILLARY SUB APICAL
OSTEOTOMY
 POTERIOR MAXILLARY SUB APICAL
OSTEOTOMY

MANDIBULAR PROCEDURES
 SAGITTAL-SPLIT OSTEOTOMY
 TRANS VERTICAL RAMUS OSTEOTOMY
 COMBINED VERTICAL RAMUS &
SAGITTAL SPLIT OSTEOTOMY
 BODY OSTEOTOMY
 ANTERIOR SUBAPICAL OSTEOTOMY
 TOTAL SUBAPICAL OSTEOTOMY
 GENIOPLASTY

SAGITTAL SPLIT
OSTEOTOMY
 ADVANTAGES:
 GREAT FLEXIBILITY IN REPOSITIONING THE
DISTAL TOOTH BEARING SEGMENT
 BROAD BONY OVERLAP OF THE SEGMENTS
AFTER REPOSITIONING OF JAWS
 MINIMAL ALTERATIONS IN POSITION OF
MUSCLES OF MASTICATION & TMJ

LeFort I Osteotomy :
 Surgical Technique :
1.when vertical changes are planned, it
is critical to place an external reference
pin and measure to a reproducible
point on the maxillary incisors. This is
accomplished by placing a Kirschner
wire through the skin and into the bone
of the nasal bridge.

 The oral incision is
placed high in the
mucobuccal fold of the
upper lip, and it extends
from the
zygomaticomaxillary but
tress region anteriorly
across the midline. As
the incision proceeds
along the lateral wall of
the maxilla, it descends
slightly anteriorly.

 When the incision is
completed bilaterally,
the lateral walls of the
maxilla are exposed
superior to the incision.
Most often, the incision
is made with a scalpel
blade or a calibrated
thermal knife.

 The use of electrocautery for the incision is
discouraged, since adverse wound healing by
excessive scarring beneath the upper lip and
nasal base may affect the length of the lip
and the amount of exposed vermilion of the
upper lip.

 The anterior nasal spine and piriform rim are
identified and the septopremaxillary ligament
is removed from the anterior nasal spine.

 The direction of the
posterior dissection is
inferior and posterior to
the zygomaticomaxillary
buttress to the pterygoid
plate.

 vertical reference
points are placed at the
piriform aperture region
and at the
zygomaticomaxillary
buttress area.
 Horizontal score marks
are not placed on the
maxilla since the teeth
serve as the reference
in the saggital plane

 The design of the lateral maxillary osteotomy
is tailored to the patient’s aesthetic needs.
For instance, if the patient requires greater
augmentation of the cheek or infra-orbital
region, the osteotomy incorporates the
zygomaticomaxillary buttress as well as the
higher aspect of the lateral maxillary wall.

 The osteotomy should always be designed so
that it terminates inferiorly in the piriform
aperture region (under the inferior turbinate).
This minimizes the risk to the nasolacrimal
system.

 Normally, a retractor is placed at the junction of the
maxilla with the pterygoid plate, and this provides
adequate exposure to ensure safety. The posterior
osteotomy is directed inferiorly as it proceeds
posteriorly from the zygomaticomaxillary buttress to
the junction of the maxilla and the pterygoid plate.
This minimizes the risk of damaging the maxillary
artery or any of its terminal branches as they
descend from the pterygopalative fossa.

 The posterior osteotomy should be 5 mm
superior to the second molar (approximately
25 mm from the occlusal plane) to minimize
the risk of devitalizing teeth.

 After the posterior wall
is cut, the saw is
reversed so that the
blade is placed into the
maxillary sinus and the
osteotomy is completed
from the sinus to the
outside.

 With care to preserve
the nasal mucosa, a
septal osteotome is
malleted posteriorly,
freeing the cartilage and
bone of the nasal
septum and vomer from
the maxilla.

 Attention is then
directed to the lateral
nasal walls. A periosteal
elevator is placed
subperiosteally on the
medial aspect of the
lateral wall of the nose.
This protects the nasal
mucosa during
sectioning

 The osteotome should
be placed at the piriform
rim and directed
posteriorly and inferiorly
along the lateral nasal
wall toward the
perpendicular plate of
the palatine bone. The
lateral nasal wall is thin
and offers little
resistance to sectioning
until the palatine bone is
reached. www.indiandentalacademy.com

 Resistance to the advancing osteotome as
well as an audible change when malleting the
osteotome indicates that the palatine bone is
encountered. Complete sectioning of the
palatine bone should be accomplished, even
if it results in damage to the descending
palatine vessel.

 When the descending palatine vessel is
damaged during this maneuver, hemorrhage
may be encountered; it can be controlled with
packing and further injection with a
vasoconstrictor.

 The final step in the LeFort I osteotomy is
separation of the maxilla from the pterygoid
plates. This is done with a curved osteotome,
which is directed medially and anteriorly at
the lowest part of the junction of the maxilla
and the pterygoid plate.

 The osteotome is malleted to achieve bony separation

The maxilla is now ready for
downfracturing. With hand
pressure, the anterior aspect
of the maxilla is gently
depressed. If significant
resistance is encountered, it
is likely that the lateral nasal
wall (perpendicular part of
the palatine bone) has been
incompletely sectioned. If
this occurs, the spatula
osteotome should be placed
and malleted to complete the
osteotomy.

 A rongeur is used to
remove any remaining
vomer or nasal crest of
the maxilla, particularly
if superior repositioning
of the maxilla is
planned. Similarly, the
lateral nasal walls are
also reduced when
necessary.

 The anterior nasal spine should not be
removed unless necessary to facilitate
superior repositioning of the maxilla since this
is important for nasal tip support.

 The descending palatine neurovascular
bundle is commonly visualized in the
posterior and medial aspect of the maxillary
sinuses. Bone should be removed carefully
from the posterior maxilla and from around
the descending palatine vessels with a
rongeur, osteotome, or bur

 If superior or posterior repositioning is
planned, it is critical to remove sufficient
quantities of bone at the posterior and medial
parts of the maxilla. Bony interference is
common in this area and may prevent the
planned repositioning of the maxilla.

 If the maxilla is repositioned superiorly, bone
from the nasal crest of the maxilla and
cartilage from the nasal septum should be
resected sufficiently to allow the maxilla to be
elevated.

 The sequence of performing these
osteotomies (lateral maxillary walls, nasal
septum, lateral nasal walls, and
pterygomaxillary junction) permits quick
mobilization of the maxilla if hemorrhage is
encountered during the procedure.

 Once the maxilla is positioned, the distances
between the vertical reference holes, external
nasal pin, and oral reference mark are
measured to ensure the correct vertical
repositioning

SAGITTAL-SPLIT
OSTEOTOMY : SURGICAL
TECHNIQUE

 Osteotomy
 The basic osteotomy pattern includes cuts just
through the cortical bone: on the medial side of the
ramus above the lingual, down the anterior ramus
onto the superior aspect of the body of the mandible,
and then curving inferiorly through the lateral cortical
plate, including the inferior border.

 Before making the medial bony cut, the bone
on the medial anterior ramus and temporal
crest can be reduced with a rotary instrument
to improve access

 The horizontal osteotomy in the ramus
should extend posteriorly one half to two
thirds the anteroposterior dimension of the
ramus.

 The vertical component of the osteotomy in
the body of the mandible should include the
inferior border.

 The position of the inferior alveolar
neurovascular bundle just under the lateral
cortical plate of the body of the mandible
dictates that the vertical osteotomy be just
through the cortical plate.

 The bone over the neurovascular bundle is
greatest over the area of the second molar,
and the vertical cut should be made here

 Following the
completion of the
osteotomy pattern
through cortical bone, a
thin spatula osteotome
malleted into the
osteotomy sites better
defines the cuts,
beginning in the medial
cut, working down the
ramus, continuing on
the body, and finishing
at the vertical cut

 Care is taken to keep
the spatula osteotome
directed just beneath
the cortical plate to
prevent damage to the
neurovascular bundle.

 As the mandible splits, care is taken to
identify the course of the neurovascular
bundle, making certain that portions of it are
not contained in the proximal condylar
segment.

 If the bundle is found to be attached to the
proximal segment in some area, the covering
bone should be removed and the nerve free
with an instrument

 The osteotomy is repeated on the opposite
side of the patient’s the distal mandible is
repositioned. The teeth are secured to the
maxilla with MMF (25-gauge wire) and with
the aid of an occlusal wafer splint.

 The distal tooth-bearing
segment should move
easily to the new
position.

 If the mandible is advanced, the medial
pterygoid muscle should be released at the
inferior aspect of the distal segment with a
periosteal elevator

 If the mandible is set back, release of the
medial pterygoid muscle and the masseter
muscle at the posteroinferior border may be
necessary to prevent displacement of the
condylar segment posteriorly.

 With a mandibular setback, sufficient bone
must be trimmed from the anterior aspect of
the proximal condylar segment to allow it to
rest passively against the tooth bearing
segment with the condyle in proper position.

 Four methods of
interosseous fixation will
be discussed: upper
border wiring, lower
border wiring,
circumramus-body
wiring, and the option
most effective to day,
RIF with lag screws,
position screws, or
small bone plates.

TRANSORAL VERTICAL RAMUS
OSTEOTOMY:
SURGICAL TECHNIQUE

 Better visibility and additional access for
bony cuts are needed or if there is to be more
than a few millimeters of mandibular
repositioning, the coronoid process should be
released.

 With a small reciprocating saw, a cut to
release the coronoid is made from the
sigmoid notch at the base of the coronoid
process extending through the anterior
ramus.

 The coronoid fragment is removed after
dissecting free the attached temporalis
muscle.

 A slight bony elevation midramus
corresponds to the position of the medial
entrance of theneurovascular bundle,
directing the line of the osteotomy through
both medial and lateral cortical plates of bone
from an area in front of the condyle to a point
at or near the angle of the mandible.

 The osteotomy cut begins at the superior
aspect of the ramus, where visibility is usually
excellent, particularly after releasing the
coronoid process. The cut is carried through
the mandible, continuing down to a point at or
near the angle.

 verify the direction of the osteotomy before
completion because it is easy to become
disoriented and make the cut too close to the
posterior border or too far anteriorly.

 If the osteotomy is directed too far posteriorly,
a subcondylar-type osteotomy can occur.

 If the osteotomy is directed too far anteriorly,
increased danger of injury to the inferior
neurovascular bundle exists.

 A number of reciprocating saw blade designs
exist, and the resulting oblique bone cut
allows for greater bony contact of the
overlapped segments.

 When the osteotomy has been completed,
the proximal condylar fragement may tend to
displace medially.

 Often it is necessary to strip some of the
remaining periosteal and muscle attachments
from the inferior medial aspect of the
proximal condylar fragment, as well as along
the posterior border, to allow the fragment to
remain in a lateral position.

 The wire or suture is passed beneath the
periosteum on the medial aspect of the
mandible, picked up at the posterior aspect of
the ramus, and carried around and lateral to
the proximal segment.

Soft Tissue Changes associated with
Skeletal Repositioning
 Mandibular Advancement
 Frontal Changes
 Increasing the lower anterior facial height
 Reduces lip eversion
 Reduces mentolabial fold (Lower lip rolls back)

 Profile changes
 Increses chin prominence
 Decreases lower lip vermlion exposure
 Increases lip fullness
 Decreases chin throat angle
 Decreases mentolabial fold

Mandibular Setback
 Frontal Changes
 Decreases chin prominence
 Makes upper lip vermilion more permanent
 Decreases lower 1/3rd
of face
 Profile Changes
 Decreases mandibular antero-posterior prominence
 Reduces lower lip vermilion exposure
 Reduces chin throat length
 Increases chin throat angle

Maxillary Advancement
 Frontal Changes
 Increases fullness of upper lip
 Increases visibility of upper lip vermilion
 Increases alar base width
 Increases paranasal fullness

 Profile Changes
 Increases paranasal area fullness
 Deceases the prominence of chin and nose
relatively
 Elevates the nasal tip
 Increases the upper lip fullness

Maxillary Superior Repositioning
 Frontal Changes
 Decreases incisor exposure
 Decreases gummy smile
 Decreases lower anterior facial height
 Improves the competency of lips
 Reduces upper lip vermilion exposure
 Increases alar base width
 Reduces upper lip length

 Profile
 Elevates nasal tip
 Decreases lower anterior facil height
 Decreases interlabial distance
 Increases antero-posterior mandibular
prominence
 Increases paranasal fullness

Maxillary Inferior Repositioning
 Frontal Changes
 Increases upper lip length
 Increaes lower anterior facial height
 Increases upper lip vermilion exposure
 Increases maxillary tooth exposure

 Profile Changes
 Increases upper lip prominence
 Makes nasolabial angle obtuse
 Makes mandible less prominent antero-
posteriorl

Conclusion
 “It is not the smile which affects happiness
but happiness which affects the smile.”
 Only by working in co-ordination with one
another can a constructive goal be achieved.

References
 Contemporary Orthodontics – William Proffit
 Essentials of Orthognathic Surgery –
Reyneke
 Esthetic Orthodontics & Orthognathic Surgery
– Sarver
 Orthodontics: Current Principles &
Techniques – Graber, Vanarsdall
 Mandibular Growth Anomalies – H. L.
Obwegeser

References
 Contemporary Treatment of Dentofacial
Deformity – Proffit & Sarver
 A Frontal Assymetry Analysis – JCO (1987);
Grummons & Kappeyne.
 Surgical Orthodontic Treatment Planning:
Profile Analysis and Mandibular Surgery – AO
(1976); Worms, Isaacson, Speidel.
 Cephalometric Prediction for Orthodontic
Surgery – AO (1972); McNeill, Proffit, White.

References
 Projecting the soft-tissue outcome of surgical
and orthodontic manipulation of the
maxillofacial skeleton – AJODO (1983);
Kinnebrew, Hoffman, Carlton.

Surgical orthodontic treatment

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