orthognathic complications

CONTENTS

• Presurgical• Intraoperative• Vascular• Neural• Unwanted fragmentation

• Post operative• Loss of vascularity : aseptic necrosis• Nose• Lip• Infection• Nonunion/delayed union• Occlusal disturbances• TMJ dysfunction• Relapse• Rare complications

“Unintended consequence of the surgery that causes harm to the patient, occurring either intra-operatively or early and late post-operatively.”

• A complication is so named because it complicates the situation.

• “No matter what measures are taken, doctors will sometimes falter, and it isn't reasonable to ask that we achieve perfection. What is reasonable is to ask that we never cease to aim for it.”

•― Atul Gawande, Complications: A Surgeon's Notes on an Imperfect Science

N = 1000 patients (1983-2002)

INTRA AND PERIOPERATIVE COMPLICATIONS OF THE LEFORT I INTRA AND PERIOPERATIVE COMPLICATIONS OF THE LEFORT I OSTEOTOMY: A PROSPECTIVE EVALUATION OF 1000 PATIENTSOSTEOTOMY: A PROSPECTIVE EVALUATION OF 1000 PATIENTS

Kramer; J CrFac Surg Vol 15,6 Nov’04

Incidence of complications and problems related to orthognathic surgery Incidence of complications and problems related to orthognathic surgery Su-Gwan Kim, Sun-Sik Park ; JOMS 65;2438-2444,2007

N = 301 (1998-2005)Neurosensory deficit - IAN - Commonest complication 73.3% - BSSO.Bleeding in Lefort I – most serious complication – Maxillary a.Inappropriate fragmentation - 5% - BSSO

SUMMARYSUMMARY

• Total range of Incidence of complications – 6.4-9.7%

• Complication rates: more - craniofacial deformities

• Commonest : paresthesia with IAN 36%- 91%

• Most serious – bleeding (immediate/delayed)

• Avg. infection rates :1.1%-4%

• Ischemic necrosis rare: more with multiple segmentation

CLASSIFICATIONCLASSIFICATION

Pre-surgical

Intra - operative

Post – operative

Dimitroulis 1998 J Adult Orthod Orthognath Surg

PRESURGICAL

Lack of pre treatment objectives

Laboratory errors

Orthodontics

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

Inability to perform the ideal procedure

Undesired esthetic and occlusal results

Creation of new problems and revision procedures

Presurgical : Lack of pre treatment objectives

Unsatisfactory bite registration

Discrepancy in mounting the cast

Improper model surgery

Warpage of splints

Presurgical : Laboratory errors

• Insufficient decompensation

• Inadequate transverse coordination

• Uncorrected tooth size problems

• Inadequate preoperative root divergence in segmental surgery

• Active orthodontic wires at surgery

• Orthodontic appliances

Presurgical : Orthodontics

Presurgical

Intraoperative

Post operative.

Vascular - Hemorrhage

Neural

Fragmentation

Maxillary descending palatine

• Incidence : 1-1.1%

Causes:

- Supra-periosteal reflection

- Posterior wall osteotomy cut directed superiorly

- Forced downfracture and mobilization of maxilla

- Elevation of nasal mucosa from nasal floor

Intraoperative: Hemorrhage in Maxilla

Pterygomaxillary dysjunction (commonest cause)

Intraoperative: Hemorrhage in Maxilla

Management :

- Visualization of problem area

- Rapid completion of osteotomy: down fracture maxilla

- Packing and direct pressure, vascular clips, electrocautery

Turvey TA, Fonseca RJ: J Oral Surg 38:92, 1980

Intraoperative: Hemorrhage in Maxilla

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 : Inf alv artery lower margin: facial a. damage

IVRO sigmoid notch: Massetric artery ramus Inferior: Inf Alv artery

Intraoperative: Hemorrhage in Mandible

Intraoperative

Vascular

Neural

Unwanted fragmentation

• Neuropraxia

• Axonotemesis

• Neurotemesis

Intraoperative: Nerve injuries

Causes for Inf Alv Nerve damage: Dissection

Splitting Movements Stabilization: comp- injury

Canal - natural pathway for direct nerve regeneration.

Intraoperative: Nerve injuries - Mandible

Predisposing factors?

Low mandibular body height

Inferior position of nerve

Inferior alveolar n. injury

Prevention:Management

Tension-free suturing

of nerve

Osteotomy design

Protection

Chisel placement

Decompression of lateral fragment

Steroids

Intraoperative: Nerve injuries - Mandible

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

Intraoperative: Nerve injuries –Facial N.

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

Intraoperative: Nerve injuries –Lingual N

• Not studied as thoroughly as mandible

• Terminal branches of infra-orbital nerve

• Clean incision Gentle dissection retraction

• Usually temporary

• Recovery 2-8 weeks.

Intraoperative: Nerve injuries –Maxilla

Intraoperative

Vascular

Neural

Unwanted fragmentation

“Deviation from osteotomy line during osteotomy procedure, resulting in osteotomy in area unrelated to surgery”

Maxilla Mandible

Intraoperative: Fragmentation

Factors:

• Bone architecture

• Bone density

• Unanticipated fractures

• Difficult fixation

• Impacted third molar

Intraoperative: Fragmentation

Sequalae :

• Infection

• Sequestration of the fragments

• Delayed bone healing

• Pseudoarthrosis

• Post operative instability & Relapse

• TMJ

Intraoperative: Fragmentation

Presurgical

Intraoperative

Post operative

POSTOPERATIVE

Loss of vascularity : aseptic necrosis

Anatomic variations: Nose, Lips

Nonunion/delayed union

Infection

Occlusal disturbances

TMJ dysfunction

Relapse

Aseptic necrosis:

• Anterior maxillary osteotomy

• Transversal maxillary segmentations

• Transection/kinking of vascular pedicle

• Major anatomical irregularities

• Poor flap design, Tearing of flaps

Postoperative: loss of vascularity - maxilla

Consequences :

-Loss of entire maxilla or segment,

-Flattening of papilla, Non vital teeth

Prevention

-Tease out descending palatine vessels during intrusion/retrusion

-Fewer Segmentation: avoid small segments

-Avoid damage to pedicle

Postoperative: loss of vascularity - maxilla

• Dr Hall HD -1978.

• 15 years - medically fit female - Le Fort I osteotomy with maxillary rib graft augmentation + BSSO + genioplasty

• 3 stage surgical plan - hyperbaric oxygen + prosthodontics involvement

• Initially 30 treatments of hyperbaric oxygen at 2.4 kPa.

• At the first operation- remaining maxillary teeth were removed + maxillary sinus and necrotic alveolar bone debrided + alveolus reconstruction with an iliac crest graft secured with miniscrews and cancellous bone,

• Interruption in Inf Alv artery:

- mandibular br 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

Postoperative: loss of vascularity - mandible

• Risk in IVRO > BSSO

• Maintain buccal& lingual pedicles in extensive genioplasty

• Excess advancement: stretches nutrient vessel

• Ischemic tissue: intraoral free graft.

• Meticulous irrigation – supportive therapy

• HBO therapy promotes neovascularization

• Reconstruction

Management

Postoperative: loss of vascularity - mandible

POSTOPERATIVE

Alteration in Nasal form - Septum - Alar Base

Loss of vascularity : aseptic necrosis

Nose

Lip

Nonunion/delayed union

Infection

Open bite and lateral shift

TMJ dysfunction

Relapse

Nasal Septum deviation:

- Maxillary impaction : encroachment on Presurgical dimension of nasal septum

- Maxillary advancement buckling

Failure to reposition :

- Septal deviation – obstruction

- Abnormal position of columella/nasal tip

Postoperative: Nose

Intraop- Resection of inferior aspect of septum- Trim septal spurs if present- Trim bone from nasal crest of maxilla- Groove in superior aspect of maxilla

Septal deviation - How to avoid?

Management-Reoperation- Delayed septoplasty

Postoperative: Nose

Alteration in alar base and perioral structures

• Alar base widening

• Prominent alar groove

• Upturning of nasal tip – obtuse nasolabial angle

• Flattening and thinning of upper lip

• Downturning of labial commisures

Postoperative: Nose

Alar cinch suture

Pyriformplasty

Alteration in alar base and perioral structures

Postoperative: Nose

POSTOPERATIVE

Loss of vascularity : aseptic necrosis

Nose

Lip

Nonunion/delayed union

Infection

Occlusal disturbances

TMJ dysfunction

Relapse

Rare Complications

Postoperative: Lip

V-Y closure of the lip is done to prevent the shortening of the lip.

POSTOPERATIVE

Loss of vascularity : aseptic necrosis

Nose

Lip

Infection

Nonunion/delayed union

Occlusal disturbances

TMJ dysfunction

Relapse

Rare complications

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

POSTOPERATIVE

Loss of vascularity : aseptic necrosis

Nose

Lip

Infection

Nonunion/delayed union

Occlusal disturbances

TMJ dysfunction

Relapse

Blindness

Causes

Local compromised blood supply

scarring , large advancement

large bite force - habits

postero-superior positioning

Systemic co-morbities- smoking

Prevention : principles of fixation techniques graft Bone gaps > 5mm auxillary forms of stabilization

Postoperative: Nonunion/delayed union - maxilla

Causes :

• Instability of fixation devices

• Avascular necrosis

• Large advancements with less bony contact (>7mm)

• Post op trauma

• Parafunctional habits

IVRO > BSSO

Postoperative: Nonunion/delayed union - mandible

POSTOPERATIVE

Loss of vascularity : aseptic ncecrosis

Nose

Lip

Nonunion/delayed union

Infection

Occlusal disturbances

TMJ dysfunction

Relapse

Rare Complications

POSTOPERATIVE - OCCLUSAL DISTURBANCES

- Posterior interference: maxilla when patient in IMF

- Maxilla fixed with condyles out of glenoid fossa

- 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

Open Bites

Management :

- minor discrepancies aggressive orthodontics

- Posterior open bite < 3mm vertical elastics

- Severe discrepancies surgery

POSTOPERATIVE - OCCLUSAL DISTURBANCES

POSTOPERATIVE - OCCLUSAL DISTURBANCES

Lateral shift

Causes:

–Inadequate advancement of one side

–Equal advancement with midline shift

–Torqueing of the proximal segment

Management:

–Elastic traction

Postoperative

Loss of vascularity : aseptic ncecrosis

Nose

Lip

Nonunion/delayed union

Infection

Open bite and lateral shift

TMJ dysfunction

Relapse

Rare Complications

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

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

POSTOPERATIVE – TMJ DYSFUNCTION

Postoperative – TMJ dysfunctionCondylar sag

Central Peripheral I & II

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

• resultant vector is anterosuperior

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

Postoperative – TMJ dysfunctionCondylar Resorption

POSTOPERATIVE

Loss of vascularity : aseptic ncecrosis

Nose

Lip

Nonunion/delayed union

Infection

Open bite and lateral shift

TMJ dysfunction

Relapse

Rare Complications

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

POSTOPERATIVE - RELAPSE

Factors :

• Magnitude of mandibular advancement or setback,

• Stretch of surrounding soft tissue,

• Positioning of mandibular condyles

• Method of fixation

• Growth of mandible

• skeletal behavior among hyper/hypodivergent skeletal patterns

POSTOPERATIVE – RELAPSEMANDIBLE

• Obligate relapse after mandibular advancements >7mm

• Mandibular setback >12 mm - less skeletal relapse

• Closure of anterior open bite with only mandibular osteotomies

POSTOPERATIVE – RELAPSEMANDIBLE

How to reduce/avoid :

• Counterclockwise rotation of the mandible be avoided

• Mandibular advancement limited to < 7mm

• Bimaxillary surgery

Depends on :

• Degree of surgical advancement

• Degree of inferior repositioning of anterior maxilla

• Use of bone grafts in large advancements

POSTOPERATIVE – RELAPSEMAXILLA

Other Causes :

- Increased soft tissue stretching results in drift of the

screws during bone healing

- Reduced area of bone contact at the lateral aspects of the

maxilla - compromised union

- Preoperative scarring - Cleft maxilla

Postoperative – RelapseMaxilla

• Postoperative relapse was not considerable after total maxillary setback surgery.

• Although the amount of maxillary setback was greater, postoperative relapse did not increase significantly.

• Significant osseous regeneration at the pterygomaxillary region occurred in the early phase of recovery.

• On average, 18% of the horizontal maxillary repositioning was lost.

• Most of the change (89%) occurred during the first 6 months postoperatively.

• Relapse increased significantly with degree of surgical advancement and degree of inferior repositioning of anterior maxilla.

Remedy for prevention:

• Advance the maxilla at least 2mm more than the ideal overjet

to compensate for relapse

• Provision of a period of MMF (3—4 weeks) in addition to rigid

fixation in large advancements –

Postoperative – RelapseMaxilla - Management

Van Sickels BJOMS 1996;34:279—85.

POSTOPERATIVE

Loss of vascularity : aseptic ncecrosis

Nose

Lip

Nonunion/delayed union

Infection

Open bite and lateral shift

TMJ dysfunction

Relapse

RARE COMPLICATIONS

RARE COMPICATIONS

BLINDNESS (vasculature damage/hypoxia)

LOSS OF FUNCTION OF LACRIMINAL GLAND

CRANIAL NERVE PALSIES

DAMAGE TO INTERNAL CAROTID ARTERY

• Abnormalities of the pterygoid plates ranging from mild hypoplasia to complete absence.

• Excessive thickness of the posterior maxillary wall, which is normally hypoplastic,

Devastating complication – mechanism not clear

• Immediate swelling eyelids

• 1st post-op unable to open eye

• Manual lift –no light perception

• Intense chemosis, loss of abduction, pupillary dilatation

88

• MRI- NAD

• CT- Complex fractures of the pterygoid plates on both sides greater wing sphenoid, sinus

• Bone fragments in inferior orbital fissure

PTERYGOMAXILLARY DYSJUNCTIONschuchardt 1942

Maxillary tuberosity + Pyramidal process of palatine bone +Pterygoid plates of sphenoid

Disarticulated easily during childood (melsen & ousterhout 1987)Complexity of sutures increases with ageCause: adverse transmission of forces to skull base via sphenoid bonePrecaution during Pterygomaxillary dysjunction

RARE COMPICATIONS

BLINDNESS (vasculature damage/hypoxia)

LOSS OF FUNCTION OF LACRIMINAL GLAND

CRANIAL NERVE PALSIES

DAMAGE TO INTERNAL CAROTID ARTERY

• Color Doppler – left internal carotid flow

POST-OP 1

POST-OP 19

POST-OP 2 MONTHS

CONCLUSION

• Congenital hypoplasia internal carotid

• Statistically significant reduction in intraoperative blood loss

• Statistically significant correlation between the surgeon's perception of the quality of the surgical field and intraoperative blood pressure,

• No statistically significant decrease in operative time when hypotensive anesthesia was used.

• 3rd post-op day - CSF discharge - left nostril,

• confirmed by laboratory analysis- did not resolve

• CT cysternogram was performed.

• A lumbar drain was placed and the CSF leak resolved over several days. There were no long-term sequelae.

• Nuerological condition of unknown orgin

• Anisocoria-inequality of pupils

• Damage to innervation of ciliary muscles / ciliary ganglion

• Complete recovery in 48 hours

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

Cognitive behavior therapy (CBT) - effective treatment BDD.

A meta-analysis found CBT more effective than medication after 16 weeks of treatment.

CBT may improve connections between the orbitofrontal cortex and the amygdala

CONVERSION DISORDER, 4-DAY BLUES, DEPRESSION

• Arises from the situation that has overwhelmed their usual ability to cope - hysteria

• reassure them of recovery, minimize secondary gain that may prolong recovery, honest disclosure about diagnosis, and reinforce

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

• Perforation of lateral nasal mucosa by fixation screws

• OAF, Eustachian tube malfunction- damage TVP

WITCH’S CHIN

“A surgeon who has not come to cross paths with complications,

is the one who has not operated enough ”

CONCLUSION

When a true complication occurs, early recognition, rapid response and effective resolution is essential

REFERENCES

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.