Oral and Maxillofacial
Dentofacial deformity and
Dr. Haytham A. Al Mahalawy, PhD
Lecturer of Oral & Maxillofacial Surgery
Mandibular Retrusion (Micrognathia)
It means small jaw.
Interference with condyler
growth in early life (trauma,
Treatment is difficult due to:
1- minimal bony substance to
2- soft tissue may be less than
B- Mandibular deficiency
retruded position of the chin as viewed from the profile.
excess labio-mental fold
abnormal posture of the upper lip,
and poor throat form,
class II molar and cuspid relationships
an increased overjet in the incisor area.
Incisor crowding in the lower jaw
Techniques of surgery
Mandibular advancement techniques:
1. Sliding step-like osteotomy
2. Horizontal L- sliding osteotomy
3. Vertical osteotomy of the ramus with bone graft
4. Vertical L- sliding osteotomy of the ramus without graft
5. Inverted L osteotomy
6. Bilateral sagittal split osteotomy
1- Sliding step-like osteotomy
By an extra-oral submandibular
The reciprocating saw and a
carbide fissure bur are used to
make the vertical cuts
A horizontal cut is then done
paralleling the plane of
Final separation of cuts by thin
flat chisel and mallet or by
placing the edge of periosteal Step sliding osteotomy
elevator into the cuts & prying
the bone apart gently.
2- Horizontal L- sliding osteotomy
It is a variation of the step
For better esthetic results,
it is better to discontinue
the horizontal cut anterior
to the angle and complete
the osteotomy with a
vertical step to leave the
prominence of the gonial
3- Vertical osteotomy of the ramus with
using a vertical osteotomy
and iliac crest bone grafts
in the area of the
4- Vertical L- sliding osteotomy of the
ramus without graft
Used in cases of retrognathia, but in
micrognathia bone graft must be
Vertical cut from sigmoid notch
parallel to posterior border and
posterior to the inferior alveolar
canal until a point 1.5 cm above the
inferior border of the mandible
The cut is then carried horizontally
in anterior direction to allow for
Then carried vertically perpendicular
to inferior border of the ramus
5- Inverted L osteotomy
used for lengthening the
ramus of the mandible
can be done either through
an intraoral or extraoral
To correct open bite
resulted from inadequate
length of the ramus due to
injury to condylar region in
children or due to mal-union
of condylar fractures.
6-Bilateral sagittal split osteotomy
splits the ramus and angle
region sagittally and then
slides the segments apart
maintaining the integrity of
the inferior dental bundle
Fixation by screws or plates
sometimes accompanied in
the early stage by light
a) mouth breathing
b) thumb sucking
Elongation of the lower third of the face
Excessive gingival & incisal exposure
Convex facial profile
Maxillary and Midface Deficiency
a retruded upper lip,
deficiency of the paranasal
and infraorbital rim areas,
exposure during smile,
a prominent chin relative
to the middle third of the
a class III malocclusion
with reverse anterior
Orthognathic surgeries of maxilla
1. Segmental maxillary osteotomy; e.g. anterior
maxillary osteotomy ( Wassmund approach).
2. Total maxillary osteotomy.
Le fort I osteotomy.
Le fort II osteotomy.
Le fort III osteotomy.
• One or more teeth
and their supporting
bone can be moved as
• Either distally to
• Or upwards to reduce
excessive upper incisor
Anterior maxillary osteotomy
Indicated for correction of dento-alveolar protrusion of
The anterior segment can be moved:
Superiorly Inferiorly Posteriorly
- maxillary protrusion
- marked protrusion of
- open bite
Anterior maxillary osteotomy. A, Removal of premolar teeth and bone in extraction
sites. B, Posterior positioning of anterior maxilla closes extraction spaces and
corrects excessive anterior overjet relationship,
Involve movement of the premaxillary segment of incisors
and canines as block.
Total maxillary osteotomy:
le forte 1 osteotomy
Most widely used technique,
By creating a le forte 1
fracture to allow mobilization
of the maxilla and articulation
in any other position desired.
( backward/ forward’ upward’
Then fixation in its new place
1. Treatment of protrusion and
2. Correction of open and closed
Le Fort II osteotomy
For patients with central
midface hypoplasia extending
into the naso-ethmoidal
It allows a certain amount of
lengthening of the midface,
especially of the nose with a
complete advancement of
the central midface.
Le Fort III osteotomy
Complete craniofacial dysjunction.
used primarily for correction of
total midface hypoplasia, usually
of cranio-synostotic origin as in:
Le fort II
Le fort III
Complications of orthognathic surgery
1. Vascular complications
2. Nonunion or delayed union
3. Dental and periodontal defects
4. Nerve injuries.
5. Unanticipated fractures.
6. Temporomandibular joint dysfunction.
7. Postoperative occlusal discrepancies.
8. Facial scars
Distraction osteogenesis (DO),
also called callus distraction,
callotasis and osteodistraction
It is the process of generating new
bone in a gap, created by
osteotomy, between two bone
segments in response to the
It relies on the normal healing
application of graduated controlled capacity of the own body that
tensile stress across the gap occurs between the surgically
osteotomized bone segments
adaptive changes of the surrounding soft tissues through
the tension that is generated by the distraction forces on
allows larger skeletal movement.
minimizing the potential relapse seen in acute
History of distraction osteogenesis
In 1951, Ilizarov developed a
procedure based on the biology of
the bone and on the ability of the
surrounding soft-tissues to
regenerate under tension; the
technique involved an external
fixator, the Ilizarov apparatus,
Applications in craniofacial
surgery were first seen in
1973, when Snyder
lengthening in animal model.
McCarthy published, in
1992, the first report of
mandibular lengthening in 4
children with congenital
Thereafter, its role rapidly
expanded to the mid face
and nearly all classic
approaches to craniofacial
Advantages of DO
1. Large volume of new bone formation,
2. Simultaneous regeneration of both hard and soft tissues.
3. Complex 3D bone reconstruction,
4. No additional bone graft,
5. decreased bone resorption
6. Less invasive,
7. Less relapse
1. Osteotomy and placement of distraction device.
2. Latency period (about 1 week) after which the
distraction device is activated.
3. Distraction period until the desired transport is
4. Fixation (consolidation) period (about 6-8 weeks)
during which the distraction device is passive and after
which it is removed.
Biological basis of distraction osteogenesis
There are three sequential phases for distraction:
It is the period from the performance of bone division
(osteotomy) till the onset of distraction.
This allowed for callus formation.
It ranges from 3-7 days.
In patients younger than 4-5 y,
it may be shortened or omitted
to prevent early consolidation.
2- distraction period
Gradual traction force is applied to bone and new bone is
Distraction at a rate of 1mm/ day at a frequency of 0.25
mm/ 6 hours give the most favorable results in
comparison to a slower or faster rate.
Slower rate; premature consolidation
Faster rate; fibrous union
3- consolidation period
Period at which newly formed bone is allowed to mature and
gain the necessary strength to accommodate functional
In general, 6-8 weeks is considered adequate.
Types of distraction osteogenesis
Monofocal…. Linear lengthening only
When a mandibular osteotomy is performed, & a
distraction force is applied across the site to stimulate
new bone growth, the procedure is described as
• This procedure is suitable for lengthening linear bone, but
not suitable for segmental defects where a bifocal or
trifocal system must be used.
• A disk of bone is cut from one end of the segmental
• The vascular supply to this disk of bone is maintained
by the continuity of the periosteum across the
• A distraction force is then applied to this disk of bone
which is known as the transport disk.
• The transport disk leaves a trial of formed callus behind
as it travels across the segmental defect, eventually
reaching the distal segment.
• The junction between the transport disk and the distal
segment is called the docking site.
distractor Regenerated bone
defect through the Transport disk
The system is referred as bifocal distraction when one
transport disk of bone is utilized and the trifocal when two
transport disks( one from each end of the segmental defect)
approach each other across the defect.
Osteotomy 2 transport
disks Regenerated Docking
According to site of placement
1- Extra-oral distractors.
• Permits elongation of greater distance
• Allow extraoral control of the vector of elongation
• Conserves the gonial angle by working in many directions
Infection due to the
Site of placement
2- Intra-oral distractors.
1- No visible scar
2- Precice placement of the device
3- Monocortical screws,
4- Pt. comfort
Second operation for removal,
Problems with achieving correct vectors of distraction,
Liability to infection.
Uses of distraction osteogenesis in
1. Reconstruction of alveolar process for dental implants
2. Widening of mandible &/or maxilla.
3. Lengthening different parts of mandible for management
of mandibular micrognathia.
4. Midface skeleton advancement.
5. Reconstruction of mandibular and facial defects.
6. Treatment of TMJ ankylosis.
Alveolar distraction osteogenesis
Alveolar distraction osteogenesis (ADO) was first
reported in (1996).
It is a technique used for increasing alveolar bone where
rehabilitation with dental implants is required.
Ridge augmentation methods
GBR (Guided Bone Regeneration)
Alveolar distraction osteogenesis
Advantages of ADO:
No need of a donor site thus
reducing morbidity and
operating time .
ADO can provide an unlimited
vertical bone augmentation
No bone resorption during
pre- and post-implant
placement and after prosthetic
loading, as was seen with
autologous bone graft.
Simultaneous expansion of
surrounding soft tissues.
Self – Assessment Questions
1- enumerate the surgical techniques for correction of
2- mention the osteotomy sites in BSSO operation.
3- enumerate the mandibular advancement techniques.
4- mention the names of the orthognathic surgeries of maxilla.
5- enumerate the complications of orthognathic surgeries.
6- what are the advantages of DO?
7- discuss the technique of DO.
8- enumerate the advantages and disadvantages of intra-oral
1. Contemporary Oral and Maxillofacial Surgery. 5th Edition.
2008 . Editors: James Hupp, Edward Ellis $ Myron Tucker.
2. Ossama Sweedan, Text Book of Oral and Maxillofacial
Surgery. 1st Edition. El Maiar press, Alex. Egypt. 2008.