complications in orthognathic surgey

Chaitanya diviPg, dept of omfsSibar dental college

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

205/01/23chaitanya divi (99) complications

in orthognathic surgery.

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



http://www.goodreads.com/author/show/3078.Atul_Gawande

http://www.goodreads.com/work/quotes/2710546

Pre-surgical Intra - operativePost – operative

Dimitroulis 1998 J Adult Orthod Orthognath Surg



Lack of pre treatment objectives

Laboratory errors

Orthodontics



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



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



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




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

1805/01/23chaitanya divi (99) complications in orthognathic surgery.

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



Prevention:Management

Tension-free suturing of nerve

Osteotomy designProtectionChisel placementDecompression of lateral fragment

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




Sequalae : Infection Sequestration of the fragments Delayed bone healing Pseudoarthrosis Post operative instability & Relapse TMJ




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



Loss of vascularity : aseptic necrosisNoseLipNonunion/delayed unionInfectionOpen bite and lateral shiftTMJ dysfunctionRelapse Alteration in Nasal form

- Septum - Alar Base



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

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: Lip

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



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



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



- 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 BitesManagement :- minor discrepancies aggressive orthodontics- Posterior open bite < 3mm vertical elastics- Severe discrepancies surgery



Lateral shift Causes:

◦Inadequate advancement of one side ◦Equal advancement with midline shift◦Torqueing of the proximal segmentManagement: ◦Elastic traction



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



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



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



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



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



Obligate relapse after mandibular advancements >7mm Mandibular setback >12 mm - less skeletal relapse Closure of anterior open bite with only mandibular

osteotomies 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 Use of bone grafts in large advancements



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 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.



RARE COMPICATIONS

BLINDNESS (vasculature damage/hypoxia)LOSS OF FUNCTION OF LACRIMINAL GLAND

CRANIAL NERVE PALSIESDAMAGE TO INTERNAL CAROTID ARTERY



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



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



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.



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) –

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



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



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



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

is the one who has not operated enough ”



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



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.



complications in orthognathic surgey

Education