Download TYPES OF SURGICAL-ORTHODONTIC TREATMENT

‫تقويم \ خامس اسنان‬
)4-3(‫ االء م‬.‫د‬
2017 \5 \9
Orthognathic surgery
Combined Surgical and Orthodontic Treatment
Patient
Oral Surgeon
Orthodontist
Orthognathic surgery


Orthognathic surgery refers to the surgical
repositioning of the maxilla, mandible, and
the dentoalveolar segments to achieve
facial and occlusal balance.
One or more segments of the jaw(s) can
be simultaneously repositioned to treat
various types of malocclusions and jaw
deformities.
There are only three possible treatment
ways to treat a jaw discrepancy problem
1. Modification of growth
2. Camouflage ( dental compensation
for a skeletal problem )
3. Surgical repositioning of the jaws
and/or dentoalveolar segments
Limitations Of
Orthodontic Treatment:
Both dental and orthopedic approaches to
attain ideal occlusion through orthodontic
appliances alone may be unsuccessful.
1.
Skeletal deformity may be too great.
2.
Completion of jaw growth may limit
the amount of orthodontic treatment
possible.
Limitations of Orthodontic Treatment
3. Patient may refuse to wear orthodontic
appliances.
4. Loss of posterior teeth may limit
available anchorage.
5. Some orthodontic movement are
difficult or impossible (significant
intrusion).
6. Esthetic consideration (gummy smile).
Limitations Of Surgical Treatment:
Surgery alone is not enough and may
be unsuccessful due to:
1.
2.
3.
Teeth need to be properly aligned.
Arch forms must be compatible.
Dental compensations should be
eliminated, so that teeth are well
related with respect to individual jaws.
Indications for Surgery
Severity of the skeletal malrelationship (the
envelop of discrepancy).
Esthetic and psychological considerations.
Severity of the skeletal malrelationship
• The envelop of Discrepancy
• It shows the amount of
change that could be
produced by orthodontic
tooth movement (inner
envelop); orthodontic tooth
movement + growth
modification (the middle
envelop); and orthognathic
surgery (the outer envelop).
Esthetic and psychological
considerations
• 75 %-80% of individuals referred for orthognathic
surgery seek esthetic improvement.
• Changes in the position of the nose and chin have a
greater impact on facial esthetics than changes limited
to the lips.
Surgical Procedures and
Treatment Possibilities
Correction of anteroposterior
relationships
Correction of vertical relationships
Correction of transverse
relationships
Correction of Anteroposterior
Relationships
I. Maxillary Surgery:
Maxillary advancement
Down fracture technique
Protraction of Maxilla
Correction of Anteroposterior
Relationships
Maxillary retraction:
Down fracture technique: limited by
the anatomic structure immediately
distal to the pterygomaxillary fissure.
Retraction of anterior segment by a
segmental osteotomy after (extraction
of 2 first premolars).
Correction Of Anteroposterior
Relationships:
Mandibular Surgery
Mandibular Advancement:
1. Bilateral Sagittal Split Osteotomy
(BSSO) of the mandibular ramus
Mandibular Advancement
Correction Of Anteroposterior
Relationships
Bilateral sagital split osteotomy
has the following advantages:
Intra oral approach
Broad interface of medullar surface
(Rapid healing)
Rigid internal fixation (RIF) with bone
screws
Bilateral Sagittal Split Osteotomy
( BSSO ) drawbacks
 Altered sensation in the lingual
nerve distribution ( transient
2 - 6 months ).
 Paresthesia over the distribution
of the inferior alveolar nerve.
Correction Of Anteroposterior
Relationships
Mandibular Setback:
1. Bilateral Sagittal Split Osteotomy
(BSSO)
Excellent control of the condylar
segment.
Osteosynthetic screws can be
employed for fixation.
Mandibular set back:
(cont’d.)
2.The Trans Oral Vertical Oblique
ramus osteotomy (TORVO)
(limited to the reduction of
mandibular prognathism.)
Full thickness overlapping segments
Less likely to produce neurosensory
changes

Jaws immobilization is necessary
Difficult control of the condyles
Correction Of Vertical Relationships
Maxillary Surgery:
Correction of skeletal open bite
(long face) deformity by:
Le Fort I down fracture of the maxilla with
superior repositioning of the maxilla (maxillary
impaction) after removal of bone from the lateral
wall of the nose, sinus and nasal septum.
Correction Of Skeletal Open Bite
(cont’d.)
Long- face problems are best treated by
intrusion of the maxilla leading to
Mandibular rotation around the
(autorotation)
condyle
Reduction of mandibular plane angle
Shortening of the face
Closure of the open bite
Correction of Skeletal Open Bite
Correction Of The Vertical Relationships
(cont’d.)
 Mandibular Surgery
1. Surgery to reduce mandibular plane angle
and close the open bite by rotating the
mandible down posteriorly and up anteriorly
is highly unstable due to:
a. Lengthening the ramus and stretching
the muscles of the pterygomandibular
sling( masseter, medial ptyregoid)
b. Lack of neuromuscular adaptation in
these powerful muscles.
Vertical maxillary excess
2- “Skeletal deep bite” or patients with a
“short face” problem (seen in Cl. II div.2
cases) are characterized by a long
mandibular ramus, square gonial angle,
and short nose-chin distance.
Short - face problems are best treated by
mandibular ramus surgery that allows the
mandible to move downward only at the chin.
This will lead to:
increase in the mandibular plane angle
by shortening of the ramus
opening of the gonial angle
Short Face Problems Treated by
Maxillary Surgery
Le Fort I down fracture of the maxilla to
increase face height is not stable,
therefore not used.
Correction Of Transverse
Relationships
Expansion & narrowing of the dental
arches
It is possible to move the maxillary
segments both away from and toward
the midline with relative ease and
stability.
Correction Of Transverse
Relationships ( cont’d. )
Rapid palatal expansion
Not feasible in adults, because
of the increasing resistance of
the midpalatal & lateral maxillary
sutures.
Correction Of Transverse Relationships
Surgically-assisted palatal expansion
to reduce the resistance of the
segments include:
1. lateral antral wall. Mid
palatal corticotomy.
2. Corticotomies in the midline or
3. Two para-midline vertical cuts
4. The jackscrew ( RPE ) is cemented before the surgery.
5. Activated after the bone cuts are
made to continue
for 10 -14 days followed by a period of stabilization.
• Corticotomy to hasten the orthodontic movements.
Asymmetry
Mandibular asymmetry often leads
to a secondary maxillary deformity
ex: More vertical mandibular growth
produces:
compensatory changes in maxillary
growth
tilt of the occlusal plane
Asymmetry
Mandibular deviation also leads to
compensatory changes in the mandibular
alveolar process and the chin deviates more than the
dental midline.
Surgical correction of asymmetry often requires a Le
Fort I osteotomy + BSSO for Mandibular ramus
correction.
Repositioning the chin may also be needed.
GENIOPLASTY
Is an osteotomy to free
a wedge-shaped portion
of the symphysis and
inferior border that
remains pedicled on
the genioglossus and
geniohyoid muscles.
GENIOPLASTY
This segment can be:
Advanced (advancement genioplasty).
 Moved backward (reduction
genioplasty).
 Shifted sideways to correct
asymmetry.
 Down-grafted to increase lower face
height.
 By splitting the segment vertically,
the wedge can be flared or
compressed.
Timing and Sequencing of Surgical
Treatment
General rules:
Orthognathic surgery should be
delayed until growth is completed.
Orthognathic surgery can be considered
earlier in growth deficiencies
TIMING OF TREATMENT
1. Actively growing patients with mandibular
prognathism can be expected to outgrow
their correction. “Relapse`’
2. Psychosocial problems may justify early
surgery to correct prognathism, however
retreatment may be needed
3. The Hand-wrist films to determine bone age
are not accurate for planning the exact
Timing of Surgery.
TIMING OF TREATMENT
4. The best method is serial cephalometric
tracings, until good documentations that the
adult deceleration of growth has occurred.
Diagnostic set-up
•A diagnostic set up is
employed to be sure that it will
be possible to get the teeth to
fit together if a given
orthodontic treatment plan is
employed.
Diagnostic pre-orthodontic set-up
showing the proposed extractions and
Sequence of an
Orthodontic/Surgical Plan
I. Sequence:
1. Orthodontics to correct alignment
and inclinations of teeth (no attempt
for skeletal correction.)
Note: Malocclusion may temporarily
look worse.
2.
3.
Surgery to reposition the jaws.
Finishing Orthodontics.
Objectives Of Pre-Surgical Orthodontics
1.Place teeth in their proper
relationships to mandible or maxilla.
i.e. decompensation of teeth
2. Level both arches independently:
It is sometimes necessary to level
teeth in segments, independently.
Pre-Treatment Evaluation:
Records Needed:
1. Dental casts
2. Dental radiographs
3. Facial photographs (frontal and
profile)
4. Cephalometric radiographs
Check List for Treatment Planning
A-P relationships
maxillary deficiency/protrusion
mand prognathism/deficiency
amount of deficiency
Vertical relationships
open bite
deep bite
Transverse relationships crossbites
before surgery
expansion
surgically assisted expansion
during surgery
{
Mounting of the maxillary model
Models with completed skeletal and
dental reference lines
Model (Mock) surgery
osteotomy lines
Interrupted line is the proposed osteotomy sit
Anterior view: models showing the
upper midline split to widen the
intercanine width and the lower
anterior set-down.
The splint:
A acrylic splint is made in the laboratory to transfer the model
relationship to the patient during surgery