orthognathic surgery

1. DR AIMAN NIAZ
ORTHOGNATHIC SURGERY
HOUSE OFFICER
SARDAR BEGUM DENTAL COLLEGE

2. OUTLINES
1. Introduction
2. History
3. Indications
4. Contraindications
5. Diagnosis & Assessment
6. Pre surgical orthodontic assessment
7. Orthognathic surgical procedures

3. INTRODUCTION
 The word orthognathic comes from
Greek word
orqos meaning To straighten
gnathos meaning Jaw
 It is the art and science of diagnosis ,
treatment planning & execution of
treatment by combining orthodontics &
oral and maxillofacial surgery to
correct musculoskeletal , dento-osseous
& soft tissue deformity of jaw and
associated structures

4. HISTORY(MANDIBULAR OSTEOTOMIES)
 1846-Hullihan – Anterior mandibular sub apical osteotomy & set back
 1906 – Bliar – Mandibular body osteotomy
 1907- Bliar – Horizontal Osteotomy of ramus – external approach
 1925 – Limberg – Posterior Oblique vertical ramal osteotomy
 1927 – Wassmund – Inverted L ramal osteotomy External approach
 1939- Kazanjian – Beveled horizontal osteotomy of ramus , extraoral approach
 1942- Schuchardt- Step horizontal osteotomy of ramus , intraoral approach
 1955- Obwegeser – Split sagittal ramal osteotomy
 1968- Caldwell et al – C Ramal osteotomy
 1970- Herbert, Kent & Hinds- intraoral vertical ramal osteotomy

5. The sagittal split osteotomy procedure can be used to set back or advance the
mandible , as show in fig A and B respectively
A B

6. HISTORY (MAXILLARY OSTEOTOMIES)
 1927- Wassmund – LeFort I osteotomy with the pterygomaxillary junction left
intact, elastic forces used to bring maxilla forward
 1928- Axhusen – Segmental osteotomy through mid palate
 1942- Schuchard – Staged LeFort I osteotomy , followed by pterygomaxillary
sepration; external traction used to bring maxilla forward
 1949 – Moore and Ward – Horizontal traction of the pterygoid plate
 1965 – Obwegser – Fully Mobilized the maxilla ; in a single step brought into the
predicted position

7. Location for
osteotomy
Cuts for LeFort I

8. INDICATIONS
 One answer to the question of
‘ When is a problem too severe for orthodontic treatment
only ?’
is
‘ When the combination of tooth movement and growth
modification does not have the potential to bring the patient to
normal occlusion’

9. INDICATIONS
 Severe class II & Severe class III

10. INDICATIONS
 Long face syndrome / Anterior Open Bite

11. INDICATIONS
 Chin abnormalities

12. INDICATIONS
 Facial Asymmetry

13. INDICATIONS
 Craniofacial Anomalies

14. CONTRAINDICATIONS
 Growing patients
 Minor cases
 Underlying medical conditions e.g blood disorders
 Systemic Or Local factors that may affect normal wound healing
 Compromised vascularity of surgical region
 Psychologically unstable patient
 A patient with unrealistic expectations

15. Why it is done ?
o Making Biting and Chewing easier
o Correct problems with Swallowing & Speech
o Minimize excessive Wear & Breakdown of teeth
o Correct bite fit or jaw closure issues e.g open bite
o Correct Facial Imbalance
o Improve the ability of lips to fully close comfortably
o Relieve pain caused by TMJ
o Repair facial injury or Birth Defects
o Provide relief for Obstructive Sleep Apnea
o To enhance long term orthodontic result / Stability

18. DIAGNOSIS & ASSESSTMENT
HISTORY :
 Patient age
 Patient concern
 Patient motivation and expectations
 Psychological status
 Medical and dental history
Disease
Drug

19. CLINICAL EVALUATION
 EXTRA ORAL EXAMINATION
Facial form
Facial symmetry
Facial profile
Lips evaluation
Chin evaluation
 INTRA ORAL EXAMINATION
 Tongue,palate,frenal attatchment
 Gingiva dentition,tonsils

20. CLINICAL EXAMINATION
 TMJ EXAMINATION
 Masticatory Muscle
 Mandibular Movements
 TMJ symptoms
 TMJ Signs

21. RADIOGRAPHIC EXAMINATION

23. COMPUTED
ASSISTED
ANALYSIS :
 Video
Manipulation
 Three
Dimensional
CT scan
reconstructio
n

24. DENTAL CAST ANALYSIS
 Studied individually or hand manipulated with
each other
 Assessment includes
 space analysis
Arch length
Transverse width discrepancies'
Position of tooth in arch
Relationship of maxillary dentition to
mandibular dentition

25. MODEL SURGERY WITH FACEBOW RECORDING
 Face bow helps to record relationship of maxilla to tmj
 We transfer this relationship to an articulator

27. MODEL SURGERY WITH FACEBOW
RECORDING
 Models are repositioned intact and sawn along
possible osteotomy lines to check if satisfactory
occlusion can be achieved

28. PRE SURGICAL ORTHODONTIC
TREATMENT PHASE
( 1) LEVELING & ALIGNMENT :
Dental crowding, spacing and rotations
should be corrected
 curve of spee should be flat
( 2 ) DECOMPENSATION:
in preparation for orthognathic surgery, it is
necessary to remove
any dental compensations present and to
place the teeth in a favorable position with
their supporting bone. This is called
presurgical decompensation.

29. PRESURGICAL ORTHODONTIC
TREATMENT PHASE
• DECOMPENSATION IN CLASS II DECOMPENSATION IN CLASS III
• Procline upper incisors Retrocline upper incisors
• Retrocline lower incisors Procline lower incisors
• Use of class III elastics Use of class II elastics
( 3) ARCH CO ORDINATION :
Arch expansion
Arch contraction
Occlusal plane leveling and alignment

30. AIMS OF PRESURGICAL
ORTHODONTICS
 Arch leveling and alignment
 Arch coordination
 Decompensation
 Leveling curve of spee
 Making room for surgical cuts in the dento alveolus by root divergence at that area
 Correct of upper and lower arch widths

31. POST SURGICAL ORTHODONTIC
TREATMENT PHASE
 Typically begins 4 to 8 weeks after surgery
 Soft doet and regular exercises
 Lasts for approximately 4 to 6 months & formally ends with removal of orthodontic
braces
Finishes dental alignment
Bring dentition into maximum inter cuspal relationship
 instruct patient to use retainer for long term stability
 obtain photographs , radiographic studies and dental models at debanding of
orthodontic braces and at 1 year post operatively

32. BILATERAL SAGITTAL SPLIT OSTEOTOMY
• Can be used to treat both prognathism and
retrognathism of mandible
• Obweseger & Trauner in 1957
• incision from anterior aspect of ramus which runs
along mid portion of ramus .
• and anteriorly over external oblique ridge till first
molar region
• after which it curves down in buccal vestibule
• shouldn’t injure buccal pad of fat
• mucoperiosteal flap elevated

33. BILATERAL SAGGITTAL SPLIT OSTEOTOMY
 Osteotomy performed by cutting cortical bone
 In medial aspect , cut extends just posterior to
mandibular foramen and above lingula
 Anteriorly , cut is taken to anterior border of ramus
and is continued along external oblique ridge
 Along 2nd molar region but stopped at 2nd molar
region
 A vertical cut is given & continued in inferior border
 Osteotome directed laterally to avoid damage to
neurovascular bundle
 Same procedure repeated on other side

34. BILATERAL SAGGITTAL SPLIT OSTEOTOMY
IN MANDIBULAR ADVANCEMENT
Medial pterygoid muscle separated from inferior border of distal segment
IN MANDIBULAR SET BACK :
Medial pterygoid and masseter muscles are stripped to prevent condylar
displacement posteriorly
 Rigid fixation method after osteotomy is done

36. BSSO
 In mandibular set back condylar segment and tooth bearing segment when they
overlap excess part is cut & bone is allowed to rest on cancellous part
 Wound closure
 Hemostasis achieved
 3-0 chromic catgut or vicarly

37. COMPLICATIONS
 Edema
 inferior alveolar nerve injury
 Condylar mispositioning
 bad split , multiple split
 excess bleeding

38. ADVANTAGES
 No external scar
 minimally altered condylar position
 Better healing

39. MAXILLARY OSTEOTOMIES
 SEGMENTAL MAXILLARY SURGERIES :
Single tooth dent osseous osteotomy
Corticotomy
Anterior segmental maxillary osteotomy
Posterior segmental maxillary osteotomy
Horse shoe osteotomy
 TOTAL MAXILLARY OSTEOTOMIES:
Lefort I osteotomies
Lefort II osteotomies
Lefort III osteotomies

40. LEFORT I OSTEOTOMY
 Patient in supine position with
a shoulder roll
 Nasotracheal intubation
 Tube secured with a 2.0 silk
suture
 External facial landmarks
 Done via tattoo mark at level of
medial canthus or K-wire placed
at level of nasofrontal junction
 pre operative measurements of
maxilla right and left side
should be available at time of
surgey

41. LEFORT I OSTEOTMY
 Local anesthesia injected into sulcus
Of upper lip to help with hemostasis
 Osteotmy
 During osteotomy,care should be taken
to avoid tooth roots
 Either
 maxillary advancement or set back
 Secure it with plates and screws

43. COMPLICATIONS
 Injury to Stensen duct
 Infra orbital nerve traction injury
 Unanticipated fractures ( pterygoid plate , sphenoid bone, middle cranial fossa )
 Injury to the internal maxillary artery & its branches
 Ophthalmic and lacrimal duct injury
 Avascular necrosis
 Maxillary sinusitis
 Nasal septal deviation and buckling
 Velopharyngeal insufficiency

44. GENIOPLASTY
INDICATIONS :
• receding chins, or retrogenia
• overly large or extended chins
• chins that are too short or too tall
• misaligned or asymmetrical chins
• abnormal dental bite

45. SLIDING GENIOPLASTY
 During a sliding genioplasty, a surgeon uses a saw to
cut the chin bone away from the rest of the jaw.
 They reposition the chin by sliding it forward or
backward to correct receding or protruding chins.
 Surgeons can also correct asymmetrical chins by
sliding or reshaping one side of the chin to match the
other.
 After repositioning the chin bone, a surgeon will
reattach it to the jaw with surgical screws.

47. IMPLANT AUGMENTATION
 Surgeons can reshape, elongate, or enhance a person’s chin by attaching plastic or
silicone implants around the existing chin bone.
 During this procedure, a surgeon places an implant over the chin bone, securing it
with stitches or screws.

48. ADVANTAGES
A Chin implant hase 2 advantages
A possibility of removal if patient is unhappy with results
Less risk of loss of sensation from trauma that emerges
from mental foramen to innervate lower lip