Issuu on Google+


INDIAN DENTAL ACADEMY Leader in continuing dental education





• • •

Orthognathic surgery is one of the fast developing branch in oral and maxillo-facial surgery. It is probably the most gratifying field in the whole maxillofacial surgery Orthognathic surgery in conjunction with orthodontics can do wonders in improving the appearance of the face

• Typical,facial alteration by surgery •

enhances physical appearance, thereby increases the confidence. Increase in the number of complication due to increased number of surgeries performed for facial aesthetics.

ANATOMY •MAXILLA CONSIST OF : A body 4 processes-zygomatic -Palatine -Frontal -Alveolar lateral surface of maxilla:Anterio lateral :Posterio lateral Anterio lateral surface also called as malar surface which shows canine fossa,superiorly

infra orbital foramen exist, above foramen Orbital plate of maxilla,laterally malar surface attaches to zygomatic bone,medially to frontal and nasal bone,posteriolaterally by infra temporal surface •From lower surface of body of maxilla arises alveolar process •Anterior nasal spine –a bony projection just below nasal aperture •Nasal cavity divided by nasal septum •Palatine process unites medially with alveolar process,hard palate is formed by palatal process of maxilla and horizontal plate of palatine bone

Mandible •Forms major part of lower 1/3 of face and contributes significantly to facial aesthetics •Mandible consist of horse shoe shaped body 2 vertical rami •External surface in midline has mental protuberance inferiorly,incisive fossa superiorly and laterally canine eminance •Mental foramen is apical to the premolars •Body unites with the ramus at gonial angle •The junction of alveolar process and the ramus is masked by external oblique ridge

Which extends anteriorly till mental foramen And upward to the coronoid process •The ramus of mandible exhibits anteriorly the coronoid process with tendons of temporalis attached to it and posteriorly to the condylar head and neck •Concavity between condylar and coronoid process is called as sigmoid or mandibular notch •Medial surface of the ramus exhibits on its lower half the roughened area where medial pterygoid inserts •Mandibular foramen at the center of ramus admits inferior alveolar nerve

VASCULAR SUPPLY ARTERIAL SUPPLY 1.External carotid artery 2.Facial artery 3.Lingual artery 4.Maxillary artery 5.Superficial temporal artery VENOUS SUPPLY 1.Facial vein 2.Retromandibular vein 3.internal jugular vein

NERVE SUPPLY 1.Motor nerve is Facial nerve its 5 branches are –Temporal Zygomatic Buccal Mandibular Cervical 2.Sensory nerve is Trigeminal nerve its 3 branches are – Opthalmic Maxillary Mandibular

Vascular complication •HEMORRHAGE MAXILLA - Acute injury Turvey and Fonseca proposed that most likely vessels at risk of injury during maxillary Surgery are Internal Maxillary artery and Greater palatine artery ~Massive blood loss can occur from injury to Internal Carotid artery and Internal jugular vein ~Thrombosis of internal carotid artery can occur during surgery,mortality rate of 40% and additional 52% patient left with neurological deficit

~Delayed hemorrhage can occur as early as night of surgery of maxillary lefort-I to as late as 9 days post-operatively ~During separation of maxillary tuberosity from pterygoid plates maximum risk of injury is to internal maxillary artery and its branches.

Mandibular vascular injury ~Internal carotid artery injury can occur during sagittal split osteotomy ~Injury to internal maxillary artery are also reported ~Injury due to improper handling of instrument 1.due to forceful placement of channel retractor on the lingual surface of the mandible 2.forceful use of mallet and chisel on the medial aspect of the mandible

ASEPTIC NECROSIS ~Major loss of hard and soft tissue can occur due to compressed blood supply ~flattening of dental papilla, loss of gingiva to periodontal defects in area of osteotomy ~Due to excessive stripping of bone aseptic vascular necrosis of proximal segment with sagittal split osteotomy ~In 1974 Gammer et al noted that bone usually revascularised, if not occurs substantial loss of bone can occur

NON UNION,DELAYED UNION OF BONE MAXILLA due to local or systemic factor compromised because of previous surgery,as in cleft palate large advancement

MANDIBLE Avascular necrosis,insufficient bone contact and instability of bone fragment

Any para-functional movement of jaw

Can be treated effectively By prolonged RIF

DENTAL AND PERIODONTAL INJURIES ~related to poor planning and technical errors during surgery ~common problems are cut teeth,loss of teeth,post-operative R.C.T and periodontal defects ~minimum of 3mm of space left during placement of osteotomy cut between teeth ~cut should be 5mm above root apex

Periodontal bone loss And gingival recession

FISTULAS ~Oronasal and oroantral region ~injury from saw,osteotome, rotary instrument ~while attempting to stretch midpalatal tissue


Parasthesia of teeth and mucosa is more common. ~usually sensation comes to normal with in 6 to 12 months ~injury to greater palatine neuro vascular bundle can cause permanent numbness

MANDIBLE ~Injury to inferior alveolar nerve can occur during sagittal split osteotomy ~Injury to lingual nerve can also occur but it is rare any dissection on lingual aspect of mandible in 3rd molar region can injure nerve

B.Motor nerve ~injury to facial nerve is more common with Extra oral approach than intra oral approach ~facial nerve injury have been reported both with sagittal split and vertical sub-condylar osteotomy ~It causes partial or total paralysis Retractor on medial aspect extending behind ramus

Extension of distal fragment beyond proximal segment

NASAL AND SINUS COMPLICATION A.Alteration in nasal form and septum

~repositioning of maxilla requires manipulation of nasal components and sinus as a result of these manipulation Complication can occur ~due to maxillary osteotomy adverse effect on alar base,nasal tip,supra tip depression may result in un aesthetic postoperative facial

~Maxillary septum is disarticulated from entire maxilla during lefort,anterior maxillary surgery special attention should be given while repositioning the septum ~Septal deviation and obstruction can occur during maxillary superior repositioning B.Nasal valve ~Internal nasal anatomy,nasal airway resistance altered breathing pattern

~as nasal valve is the smallest cross section of nose alteration in this area can cause nasal breathing problems C.ALAR BASE ~excessive alar base widening ~increased prominence of alar groove ~upturning of nasal tip ~flattening and thinning of upper lip ~down turning of labial commisures

D.SINUS INFECTION ~due to inadequate drainage and open fistula ~infection associated with alloplastic implant ~retention of large blood clots ~pre existing disease ~foreign object –wires, bone plates,screws

MODEL SURGERY ~it is done immediately before orthognathic Surgery ~it is important to use a face bow transfer to mount the cast on a semi adjustable articulator so that exact condyle-tooth relationship are recorded Model surgery serves two purposes 1.To verify that planned movements are possible 2.To prepare occlusal wafer splint

OCCUSAL SPLINT ~it is placed immediately after orthognathic surgery in positioning the teeth in proper occlusion for stability ~it is made on dental cast that shows the result of model surgery ~it should be thin to produce the least amount of separation of the teeth ~it should be 2mm thick in its thinnest part to resist breakage

MODIFICATION OF SPLINT ~reduction of depth of occlusal index to remove interferences ~patient must able to do lateral excursion and bite up and down ~maintain adequate thickness (2mm) ~provision of removal of splint for cleaning ball end clasp can be placed



Injury to internal carotid artery

Internal jugular vein

~INJURY TO PALATE intra operatively rowe disimpaction forceps are used to disimpact maxilla,beak of forcep injure palate

~ANSTHESIA RELATED cut in endo tracheal tube during surgery,some times patient need to be re intubated

~EMPHYSEMA cervical and facial region,some reports of air in soft tissues of head,neck and chest following lefort I osteotomy

~HEMATOMA laceration to descending palatine artery during down fracture lefort I


B.ANTERIOR SUB APICAL OSTEOTOMY ~periodontal defects In between teeth and loss of blood supply to teeth adjacent to osteotomy cuts ~discoloration of teeth ~periapical bone loss


~most commonly periodontal defects and loss of vascularity

~wound dehiscence ,change in colour and tone of mucosa prolongs healing



A.SAGITTAL SPLIT OSTEOTOMY FRACTURE BONE FRAGMENT ~ it is a problem seen more frequently with mandibular surgical procedure ~incidence of proximal segment fracture 1-3% whereas distal segment fracture 0.8% ~management of fracture depends on location and size of fracture

1.proximal segment mandible intact ~when buccal fragment shear of usually cause is inadequate bone cut ~the bone split must be completed by making a deep groove on the inferior border and connecting with previous groove ~larger fragment should be stabilized with wires or screws and plates

2.proximal segment split complete ~when fracture occur more superiorly at the ramus of mandible in horizontal direction

~fracture of condyle with coronoid and angle of mandible in separate fragment

3.lingual segment fracture ~occurrence is less frequent because of frequently impacted 3rd molar ~when unwanted fracture occurs surgeon should complete the split along the original planned osteotomy lines

~a wedge of bone can Be taken from buccal aspect and placed on lingual aspect ~stabilization can be done wires or screws and plate

4.lateral displacement ~it can occur during vertical sub condylar osteotomy ~proximal fragment or condylar fragment may be displaced medially or laterally

5.medially displacement ~in some fractures condylar fragment can Be displaced medially ~in such cases post operatively patient complains of irritation of pharynx

NERVE AND VESSELS INJURY ~injury to mandibular nerve can occur, extreme care must be taken to maintain the continuity of neurovascular bundle ~bleeding may occur from inferior alveolar neuro vascular bundle,some times facial vessels may be lacerated during surgery ~less common injury to retromandibular vein which lies adjacent to posterior border of ramus

B.TRANS ORAL VRETICAL RAMUS OSTEOTOMY ~complication in this procedure is rare ~occasionally hemorrhage results from injury to massetric artery ~injury to retromandibular vein

C.COMBINED VERTICAL RAMUS AND SAGITTAL OSTEOTOMY ~injury to inferior alveolar neurobundle ~splitting of bone fragment producing a fracture of anterior projection of lateral cortical plate anterior to ramus segment

D.INFERIOR BORDER OSTEOTOMY ~ dead space almost always is created after segments are repositioned ~wound dehiscence is more likely to occur ~loss of keratinized tissue and periodontal defects can occur anterior teeth

E.ANTERIOR SUB APICAL OSTEOTOMY ~trauma to mental nerve Which causes loss of sensation in anterior region ~planned osteotomy cuts minimize injury to nerve

F.POSTERIOR SUB APICAL OSTEOTOMY ~blood supply can interrupt causing devitalization of the segment ~teeth may not respond to stimulation for 6 to 12 month ~periodontal bone defect Neurovascular bundle

G.TOTAL SUB APICAL OSTEOTOMY ~injury to neuro vascular bundle and long term sensory disturbances ~injury to root apex

H. OTHER COMPLICATIONS SALIVARY INJURY ~ injury to parotid gland are possible with extra oral procedure ~ painless fistula can occur in first week of surgery CONDYLAR MALPOSITIONING ~inability to orient and maintain condylar position

~commonly encountered problem is “condylar Sag� which is most commonly occurs with trans oral vertical ramus osteotomy ~in condylar sag posterior segment is separated with tooth bearing segment ~in some cases class-2 molar relationship, anterior open bite occurs immediately after release of fixation

FACIAL SCARS ~with extra oral techniques chances of facial Scars are more ~this technique was traditionally used COMPLICATION OF AUGMENTATION WITH IMPLANTS ~bony defects or deficiencies in maxilla or Mandible ~bony defects are often expressed in facial Contours

AUGMENTATION MATERIAL ~autogenous bone and cartilage ~allogenous bone and cartilage ~alloplastic materials eg; silastic,proplast, hydroxylapatite AUGMENTATION PROCEDURES ~paranasal augmentation ~infra orbital malar augmentation ~anterioinferior mandibular border augementation ~posterioinferior mandibular border augmentation

~anteriolateral mandibular augmentation ~chin augmentation COMPLICATION ~if dehiscence occurs with implants correcting the problem is difficult,loss of implant may occur if wound does not heal with secondary intention ~wound infection can also be a serious consequence ~shifting and migration of implant

POST-OPERATIVE ORTHODONTIC COMPLICATION ANTERIOR OPEN BITE ~it can be due to condylar distraction with Mandibular surgery ~inadequate posterior impaction in lefort I Surgery ~it can be managed with headgear

LATERAL OPEN BITE ~no occlusal contact of posterior teeth after Surgery ~tripod effect should be created to prevent Forcing of condyle head into the fossa ~after buccal segment are in occlusion splint And composite can be removed ~several month of archwire stabilization is Necessary

ASYMMETRY ~midline asymmetry frequently occurs together with buccal segment asymmetry ~it is important to identify source of problem ~submentovertex radiograph can be helpful

MAXILLA ~if asymmetry exist in maxilla headgear, Heavy elastics can be helpful ~posterior crossbite bilaterally cross elastics Can be used

~In severe cases asymmetrical headgear Is used to correct rotated maxilla

MANDIBLE ~due to surgical malposition crossbite and Midline discrepancy ~sufficient elastic traction is applied in Appropriate vector to achieve good occlusion

TEMPROMANDIBULAR JOINT DYSFUNCTION A.SHORT TERM ~some patients develop TMJ problem after surgery ~there can be acute or gradual increase in symptoms ~acute condition can be managed with anti-inflammatory and physical therapy like 1.EMG bio feed back and relaxation training 2.ultrasound 3.spray and stretch 4.friction massage

B.LONG TERM ~condylar resorption has been noted after wire osteosynthesis and rigid fixation ~studies have shown that majority of relapse Is due to movement at osteotomy site and not at the condyle

SURGICAL RELAPSE PROFFIT AND WHITE (1970),A.O,were among the first to mention relapse after surgical-orthodontic therapy. They felt that relapse could be avoided by concentrating on eliminating the original causes contributing to the original malocclusion as much as possible, and by not operating while patients are still growing

POULTON AND WARE (1971),AJO, stated that, “Probably the suprahyoid muscles, which have been lengthened, are the main force contributing to the relapse.�

Theories for relapse: AJO-DO 1991

satrom, sinclair, wolford

1. stretching of the muscles of mastication and the suprahyoid musculature, 2. condylar distraction during surgery, 3. upward and forward rotation of the mandible, 4. changes in rotational position between the proximal and distal segments.

Numerous fixation techniques to reduce postsurgical relapse: 1.upper- and lower-border wiring 2.Steinmann pins to stabilize the maxilla 3.skeletal-wire fixation 4.rigid fixation Studies that examined independent mandibular advancements and maxillary LeFort I procedures have indicated a strong tendency toward reduced amounts of relapse when either skeletal-wire fixation or rigid fixation is used.

Three principles that influence post-surgical stability I) Stability is greatest when soft tissues are relaxed during the surgery and least when they are stretched II) Neuromuscular adaptation is essential requirement for stability III) Neuromuscular adaptation affects muscular length, not muscular orientation

“An ounce of prevention is worth a pound of cure”

THANK - U www.indiandentalacademy. com Leader in continuing dental

Complication of o s/ dental implant courses by Indian dental academy