Surgical Orthodontics O.ppt

Surgical
Orthodontics
Dr. Rakesh Kumar
Professor, Dept Of Orthodontics
Navodaya Dental College, Raichur

Etiology of dento-facial
deformities
1.SPECIFIC CAUSES
Prenatal causes
A. fetal alcohol syndrome
B. retionicacid and
thalidomide therapy
C. hemifacialmicrosomy
D. Goldenhar’ssyndrome
E. mandibulofacialdystosis
F. facial cleftingsyndrome
G. achondroplasia
H. Craniosynostosis
syndrome
I. pierrerobin syndrome

Postnatal causes
A. Injury to nasal septum
B. injury to condyle
C. injury to ramus
D. injury to alveolar bone and teeth
E. missing muscles
F. condylar hyperplasia

II. HEREDITARY
A. mandibular prognathism
B. inter racial mixing
III. ENVIRONMENTAL
A. effect of posture
B. respiratory influence
C. effect of bitting force

ENVELOPE OF DISCREPANCY
There are 3 possibilities of treatment-
1.Tooth movement by orthodontic treatment.
2.Tooth movement by orthodontic treatment
combined with growth modifications.
3.By orthognathicsurgery.

Maxilla
The first envelope shows the amount of change that
could produced by the orthodontic treatment alone.
In vertical plane of space there is more potential for
extrusion than intrusion. The envelope shows 4mm
extrusion can be done and 2mm of intrusion can be
done orthodontically.

In antero-posterior plane of space 7mm retraction can
be done and 2mm proclinationcan be done
orthodontically.
Second envelope of discrepancy indicates the changes
in the teeth movement can be achieved
orthodonticallyalong with growth modification. In
the vertical plane of space 6mm extrusion and 5mm
intrusion can be

Achieved to set the teeth in an ideal position. In
antero-posterior plane of space 12mm retraction and
5mm proclinationcan be achieved .
Third envelope shows, the changes can be achieved by
orthognathicsurgery. In vertical plane of space 10mm
downward movement and 15mm superior
repositioning of maxilla can be done .

In the antero-posterior plane of space 10 mm
advancement and 15mm set back of maxilla can be
done.

MANDIBLE
In the similar way for mandible, in the first envelope
where teeth movement can be achieved
orthodontically shows 4mm intrusion and 2mm
extrusion can be done.
In anteroposterior direction 5mm proclination and
3mm retraction can be achieved.

Second envelope where tooth movement can be
achieved orthodontically combined with growth
modificationshows in vertical plane 4mm intrusion
and 6mm extrusion can be done.
In anteroposterior plane 10mm proclination and 6mm
retraction can be done .

Third envelope shows that, in vertical plane 10mm
downward and 15mm upward movement of mandible
can be done surgically.
Antero-posterior plane 25mm of setback and 12mm
advancement of mand can be achieved surgically.
Surgery to move the lower jaw back has more potential
than surgery to advance it.

History
• Miscellaneous mandibular set-back procedures during first half of
20th century
• 1959 development of sagittal split ramus osteotomy
(Trauner/Obwegeser) to set-back or advance mandible
• 1960’s maxillary LeFortI procedure develop in Europe is
developed (Bell/Epker/Wolford)
• 1980’s possible to move either/both jaws and chin in all three
planes of space
• 1990’s rigid internal fixation

Indications for orthognathic surgery
• Skeletal discrepancy
–Significant Class II or III skeletal patterns
• Facial imbalances or asymmetries
–Long lower face, gummy smile
• Limitations of tooth movements
–Need to keep teeth relatively upright and in the
Bone
• Relapse potential of orthodontic treatment
–Excessive dental extrusion (vertical elastics),
expansion or tipping or teeth may not be stable

Surgical options (correction in all three planes of space)
• Maxilla
–Lefort I
–Zygomaticbuttress release (SARPE)
• Mandible
–Sagittal split osteotomy (BSSO)
–Vertical ramus osteotomy
–Genioplasty
-Subsigmoid(oblique sub chondylar) osteotomy.
• Misc. procedures
–Segmental osteotomy

STEPS INVOLVED IN ORTHOGNATHIC
SURGERIES :
1.DIAGNOSIS
2.PRE SURGICAL ORTHODONTICS
3.MOCK SURGERY
4.SURGERY & STABILIZATION
5.POST SURGICAL ORTHODONTICS

1.DIAGNOSIS :
a)General medical evaluation
b)Socio psychological evaluation
c)Cephalometric evaluation : PA view
Lat ceph
d) Radiographic evaluation :
i ) IOPA
ii) OPG
iii) Submento vertex view
iv ) Handwrist
v) CT
e) Study model evaluation
f) TMJ evaluation

Timing: Skeletal maturity indicators
(hand-wrist x-ray)

Timing: Skeletal maturity indicators
(cervical vertebral maturation -CVM)

Treatment Planning:
(Cephalometric guidelines)

2. PRE SURGICAL ORTHODONTICS
(duration –1 year)
a)Tooth alignment within the arches
b)Alteration & co-ordinations of the arches
c)Incisor inclinations
d)Decompensation

3.MOCK SURGERY

4. SURGERY & STABALIZATION

5. POST SURGICAL ORTHODONTICS

PRE POST

Surgical Predictions

Coming Soon: Surgical
prediction (cephalometrics)
in 3D