2. COMPLICATIONS
2
• Presurgical
• Intraoperative
• Vascular
• Neural
• Unwanted fragmentation ( bad splits )
• Post operative
• Loss of vascularity : aseptic necrosis
• Infection
• Nonunion/delayed union
• Occlusal disturbances
• TMJ dysfunction
• Relapse
• Rare complications

3. PRESURGICAL
Lack of pre treatment objectives
Laboratory errors
Orthodontics
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4. Pre-surgical
Lack of pre-treatment objectives
• Failure to recognize underlying skeletal
abnormality
• Unexpected adverse growth
• Lack of patient co-operation
• Gross skeletal deformity correction:
mainly orthodontics & minimal surgery
4

5. Unsatisfactory bite registration
Discrepancy in mounting the cast
Improper model surgery
Warpage of splints
Presurgical : Laboratory errors
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6.  Insufficient decompensation
 Inadequate transverse coordination
 Uncorrected tooth size problems
 Inadequate preoperative root divergence in segmental surgery
 Active orthodontic wires at surgery
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chaitanya divi (99) complications in
orthognathic surgery.
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Presurgical : Orthodontics

7. Intraoperative
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Vascular - Hemorrhage
Neural
Fragmentation

8. Thomas Teltzrow Journal of Cranio-Maxillofacial Surgery (2005) 33, 307–313
Vessels at risk :
-Inferior alveolar A.
- Internal carotid A.
- Massetric A.
- Retromandibular vein
- Facial vein
BSSO
medial aspect : Inferior alveolar a.
lower margin: facial a. damage
IVRO
sigmoid notch: Massetric artery
ramus Inferior: Inf Alv artery
Intraoperative: Hemorrhage in Mandible
8

9. Management :
- Visualization of problem area
- Rapid completion of osteotomy
- Packing and direct pressure, vascular clips, electrocautery
Turvey TA, Fonseca RJ: J Oral Surg 38:92, 1980
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Intraoperative: Hemorrhage

10. Intraoperative
Neural
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11. • Neuropraxia
• Axonotemesis
• Neurotemesis
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Intraoperative: Nerve injuries

12. Causes for Inferior Alveolar Nerve damage:
 Dissection
 Splitting
 Movements
 Stabilization: compression- injury
 Canal - natural pathway for direct nerve
regeneration.
12
Intraoperative: Nerve injuries - Mandible
Predisposing factors?
Low mandibular body height
Inferior position of nerve

13. Inferior alveolar n. injury
chaitanya divi (99) complications in
orthognathic surgery.
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Prevention:
Management
Tension-free suturing
of nerve
Osteotomy design
Protection
Chisel placement
Decompression of lateral fragment
Intraoperative: Nerve injuries - Mandible

14. Causes:
• Retraction medially behind ramus
• Extension of distal segment beyond prox.
segment
• Haematoma
• Genioplasty : direct trauma to marginal
branch
• Sagittal split : direct trauma to trunk
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chaitanya divi (99) complications in
orthognathic surgery.
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Intraoperative: Nerve injuries –Facial N.

15. Lingual nerve injuries
- uncommon
Causes:
• Variable course of nerve on medial
aspect of mandible
• No protection to nerve while stripping
on medial aspect
• Bicortical screws for BSSO :
overpenetration 15
Intraoperative: Nerve injuries –Lingual N

16. Intraoperative
Vascular
Neural
Unwanted fragmentation
16

17. “Deviation from osteotomy line during osteotomy procedure, resulting in
osteotomy in area unrelated to surgery”
Mandible
Intraoperative: Fragmentation
17

18. Unfavourable splits may cause fractures of the proximal or
distal segment.
The most common factor causing a proximal segment fracture
is the failure to cut the inferior border prior to applying chisels
to the osteotomy. When this occurs, the fracture line
propagates along the buccal cortex.
Adverse distal segment fractures may be splits that are short
of the lingula, medial splits up the condyle and those
occurring just distal to the second molar.

19. Factors:
• Bone architecture
• Bone density
• Difficult fixation
• Impacted third molar
19
Intraoperative: Fragmentation

20. Sequalae :
• Infection
• Sequestration of the fragments
• Delayed bone healing
• Post operative instability & Relapse
• TMJ problems
20
Intraoperative: Fragmentation

21. A Bony Landmark ‘RAI Triangle’ to Prevent ‘Misplaced and Misdirected’ Medial
Cut in SSRO
Kirthi Kumar Rai, Gururaj Arakeri J Maxillofac Oral Surg. 2011 Mar; 10(1): 90–92.
Placing and directing the bur cut taking the Rai triangle as guide; one can note the bur cut
within the triangular upper compartment sparing the lower compartment and directing
along the line bisecting the triangle

22. • Interruption in Inferior Alveolar artery:
- mandibular branch of sublingual artery
- mental artery
• Complete stripping of mucoperiosteum:
- compromise periosteal blood supply
- medullary supply is already compromised
Osteotomized segment : like free autogenous graft  necrosis
22
Postoperative: loss of vascularity - mandible

23. • Risk in IVRO > BSSO
• Maintain buccal & lingual pedicles in extensive
genioplasty
• Excess advancement: stretches nutrient vessel
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• Ischemic tissue: intraoral free graft.
• Meticulous irrigation – supportive therapy
• HBO therapy  promotes neovascularization
• Reconstruction
Management
Postoperative: loss of vascularity - mandible

24. PREVELANCE OF POSTOPERATIVE COMPLICATIONS AFTER ORTHOGNATHIC
SURGERY: A 15-YEAR REVIEW
LOP KEUNG CHOW, BALDEV SINGH, NABIL SAMMAN. JOMS 65:984-992,2007
 N = 1294 patients ; 2910 procedures-1070 -bimax; 224-single jaw
 Total complication rate – 9.7% (out of this – 7.4% - infection)
 Higher infection rate (17.3%) in single pre-op dose of antibiotics
than patients on postop antibiotics
24

25. Causes :
• Instability of fixation devices
• Avascular necrosis
• Large advancements with less bony contact (>7mm)
• Post op trauma
• Parafunctional habits
IVRO > BSSO
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Postoperative: Nonunion/delayed union - mandible

26. POSTOPERATIVE - OCCLUSAL DISTURBANCES
- Bony interferences
- Hardware Failure - screws and plates
- Fragmentation
- Edema in joints
- Condylar torque, condylar sag, incorrect placement of fragments
- BSSO- failure of rigid fixation at the osteotomy site, occlusal shifts during
fixation, and finally condylar sag
26

27. POSTOPERATIVE - OCCLUSAL DISTURBANCES
Open Bites
Management :
- minor discrepancies 
aggressive orthodontics
- Posterior open bite < 3mm 
vertical elastics
- Severe discrepancies  surgery
27

28. POSTOPERATIVE - OCCLUSAL DISTURBANCES
Lateral shift
Causes:
◦Inadequate advancement of one side
◦Equal advancement with midline shift
◦Torqueing of the proximal segment
Management:
◦Elastic traction
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29. POSTOPERATIVE – TMJ DYSFUNCTION
Intraoperative position of condyle influenced by:
• Incorrect vector during condylar positioning
• Incomplete or green-stick split  prevents condylar seating
• Muscular, ligamentous or periosteal interference
• Intra-articular hemorrhage or edema
• Flexion in proximal segment while placing rigid fixation
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30. POSTOPERATIVE – TMJ DYSFUNCTION
• TMDs  20-25% in normal population
• Karabouta & Martis – 40.8% TMDs post BSSO
• White – 49.3%
Condylar Sag
Immediate / late change in position of condyle in the glenoid
fossa after surgical establishment of a preplanned occlusion
and rigid fixation of the bone fragments, leading to a change in
the occlusion
Reyneke ; BJOMS (2002) 40, 285–292
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31. Condylar sag
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Central Peripheral I & II
Peripheral sag:
Type 1 : condyle positioned inferior with peripheral fossa contact .

32. Causes of incorrect occlusion
immediately after intraoperative
removal of MMF
• Condylar Sag
• Mobility at osteotomy
site
• Shift in occlusion
during placement of
rigid fixation

33. • Central Condylar Sag
Central sag :
Condyle positioned inferiorly in the glenoid fossa  no contact with
fossa
Removal of the IMF and in the absence of intracapsular edema or
hemarthrosis, the condyle moves superiorly  malocclusion

34. Peripheral Condylar Sag Type I
Peripheral sag:
Type 1 : condyle positioned inferior with peripheral fossa contact .

35. Peripheral Condylar Sag Type
II
Type 2 : correct condyle position in fossa, , incorrect rigid fixation
 flexural stress in the proximal segment

36. Bilateral Cental Codylar Sag
Unilateral Central Condylar Sag ( Left Condyle)

37. Bilateral Type II Peripheral Codylar Sag
Unilateral Type II Peripheral Codylar Sag (Rt condyle)

38. Intra-articular haemorrhage &/or
Edema

39. Disc displacement
• Disc displacement  Return to normal  pushes
condyle posteriorly  posterior open bite on affected

40. • The condyle is seated with the condylar seating
tool + light digital pressure at the angle. 40

41. chaitanya divi (99) complications in
orthognathic surgery.
41

42. “With all the new technology being developed one can can only wonder how we will be positioning the
condyles in future” -Ellis 1994
Orthognathic positioning system: intraoperative system to transfer virtual surgical plan
to operating field during orthognathic surgery :
Journal of Oral-MaxilloFac Surg 2013;71: 911-920 : John W Polley, Alvaro A Figueroa

43. Postoperative – TMJ dysfunction
Condylar Resorption
Change in shape of the condyle from normal to
finger shaped with loss of height and later
decrease in posterior facial height.
Van Damme JCMS 1994 ; 22, 53-58
Incidence : 2.3% and 7.7% of  BSSO
advancement
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44. POSTOPERATIVE - RELAPSE
Stability depends on :
- Adequate presurgical orthodontics
- Long-term maxillomandibular fixation
(MMF)
- Nonrigid fixation that allow muscular
adaptation
- Minimal muscle alteration
- Good bony contact, and control of the
proximal segment
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45. POSTOPERATIVE – RELAPSE
MANDIBLE
Factors :
• Magnitude of mandibular
advancement or setback,
• Stretch of surrounding soft tissue,
• Positioning of mandibular condyles
• Method of fixation
• Growth of mandible
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46. POSTOPERATIVE – RELAPSE
MANDIBLE
• Obligate relapse after mandibular advancements >7mm
• Mandibular setback >12 mm - less skeletal relapse
• Closure of anterior open bite with only mandibular osteotomies
46
How to reduce/avoid :
• Counterclockwise rotation of the mandible be avoided
• Mandibular advancement limited to < 7mm
• Bimaxillary surgery

47. Facial Dysmorphophobia
• Distorted perception of one’s self appearance
• Defect may be imagined
• Minor defect  excessive concern
• No other mental disorder associated
• ‘Doctor shopping’ and frequent requests for surgery
• History taking – most important
• Psychiatric counselling
chaitanya divi (99) complications in
orthognathic surgery.
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48. OTHERS
• Dysphagia- Constricted eosophageal sphincter hypoesthesia
due to change in anatomy of the hyoid region- reduced
tension in supra-hyoid musculature – reduced dilator effect
on sphincter
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49. WITCH’S CHIN
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50. “A surgeon who has not come to cross paths with complications,
is the one who has not operated enough ”
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51. Contemporary Oral and Maxillofacial Surgery- Larry J. Peterson
Oral and Maxillofacial Surgery 2nd Edition- Raymond J. Fonseca volume 3
Essentials of Orthognathic Surgery- Johan P. Reyneke
Online resource via Science-direct & Pub-Med.
REFERENCES
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