医学资料口腔颌面外科李祖兵下颌骨骨折课件

Mandibular Fractures,Li Zubing School of Stomatology, Wuhan University,History,A. Ancient Egypt B. Ancient Greece C. “Modern” Europe D. America,Ancient Egypt,The Edwin Smith Treatise Written approx 3000 BC, translated in 1862 “An ailment to be treated” “An ailment with which to contend” “An ailment not to be treated”,“If thou examinst a man having a fracture in his mandible, thou shouldst place thy hand upon itand find that fracture crepitating under they fingers, thou shouldst say concerning him: one having a fracture in his mandible, over which a wound has been inflicted, thou will a fever gain from it.” -Edwin Smith The cause of death was believed to be sepsis,Ancient Egypt,Ancient Greece,Hippocrates The son of a physician-priest Written in 460 BC Describes MMF!,Bandages, first mentioned by Hippocrates, gained acceptance as a standard of care when John Rhea Barton described his Barton bandage,“Displaced but incomplete fractures of the mandible where continuity of the bone is preserved should be reduced by pressing the lingual surface with the fingers while counterpressure is applied from the outside. Following the reduction, teeth adjacent to the fracture are fastened to one another using gold wire.” -Hippocrates,Ancient Greece,“Modern” Europe,The first European medical school was in Salerno, Italy in 1180 Heavily influenced by religion. “take olbaisum, mastic, colophene, glue and dragon blood; all this must be mixed with liquefied resin until it becomes ointment, which is placed over (the fracture)”,America,Thomas Gunning Designed the “Gunning splint” in 1884 His assessment and methods were highly controversial, however, and most considered his treatment unsatisfactory Mr. Thomas Pioneered open reduction with internal fixation in 1869,Thomas Gunning was the first to use vulcanite in a custom-fitted splint to immobilize mandibular fragments.,America,Thomas Gunning Designed the “Gunning splint” in 1884 His assessment and methods were highly controversial, however, and most considered his treatment unsatisfactory Mr. Thomas Pioneered open reduction with internal fixation in 1869,Thomas presented a technique of intraoral open reduction with silver wire osteosynthesis. The spiral spring-like termination was tightened intermittently “until union was secured.”,Anatomy,A. Bony landmarks B. Occlusion C. Fracture Sites D. Innervation E. Arterial supply F. Musculature G. Factors in fx displacement,Bony Landmarks,Condylar Process Coronoid Process Ramus Angle Body Symphysis/parasymphysis,Anatomic units of the mandible,Trajectories of the mandible,Occlusion,The Angle Classification: based upon the relationship of the first mandibular and maxillary molars Class I: normal occlusion Class II: an “underbite” Class III: an “overbite” Observe wear facets,Angles classification,Common Sites of Fracture,Condyle 36% Body 21% Angle 20% Parasymphysis 14% Coronoid, ramus, alveolus, symphysis 3% Weak areas include 3rd molar and canine fossa,Fracture Frequency,Innervation,CNV3, the mandibular n., through the foramen ovale Inferior alveolar n. through the mandibular foramen Inferior dental plexus Mental n. through the mental foramen,Anatomy - Mental foramen,Anatomy - Mandibular foramen,Arterial supply,Internal maxillary artery from the external carotid Inferior alveolar artery through the mandibular foramen Mental artery through the mental foramen,Musculature: Jaw Elevators,Masseter: Arises from zygoma and inserts into the angle and ramus Temporalis: Arises from the infratemporal fossa and inserts onto the coronoid and ramus Medial pterygoid: Arises from medial pterygoid plate and pyramidal process and inserts into lower mandible,Musculature: Jaw Depressors,Lateral pterygoid: lateral pterygoid plate to condylar neck and TMJ capsule Mylohyoid: mylohyoid line to body of hyoid Digastric: mastoid notch to the digastric fossa Geniohyoid: inferior genial tubercle to anterior hyoid bone,Muscles of mastication, which have a displacing influence on mandibular fractures,The tension forces along the alveolar border (-) and compression forces along the lower border (+). The arrows indicate muscular tension,Factors in fx displacement,Factors in fx displacement,Mandibular Forces,Classification by type of fracture,Classification by localization,Symphysis region between the canines Canine region Mandible body between canine and angle Mandible angle in the third molar region Mandible ramus beteen angle and signoid notch Coronoid process Condylar process,Classification of condylar fx.,Level of condylar fx. Condylar head Condylar neck Subcondylar,Classification of condylar fx.,Relationship of the condylar segment to the mandible Nondisplaced Deviated Displacement with medial or lateral overlap Displacement with anterior or posterior overlap No contact between the fracture segment,Favorable Fractures,Those fractures where the muscles tend to draw fragments together Ramus fractures are almost always favorable as the jaw elevators tend to splint the fractured bones in place,Unfavorable Fractures,Fractures where the muscles tend to draw fragments apart Most angle fractures are horizontally unfavorable Most symphyseal / parasymphyseal fractures are vertically unfavorable,Angle fractures,Parasymphyseal fractures,Diagnosis of Mandibular Fx,A. History B. Physical Exam C. Radiographic exam,Evaluation - History,Mechanism of injury MVA associated with multiple comminuted fx Fist often results in single, non - displaced fx Anterior blow to chin - bilateral condylar fx Angled blow to parasymphysis can lead to contralateral condylar or angle fx Clenched teeth can lead to alveolar process fx,Trauma in the form of an anterior blow directly to the chin can cause bilateral condylar fractures,Moving object striking a static individual resulting in trauma to the TMJ,Moving individual striking a static object resulting in TMJ fx.,Combination of forces resulting in trauma to the TMJ,Past Medical History,Pmhx Bone disease Neoplasia Arthritis, tmj (risk for ankylosis) Collagen vascular disease, endocrine d/o Nutrition and metabolic disorders, including alchohol abuse Seizure d/o,Physical Exam - Occlusion,Change in occlusion - determine preinjury occlusion Posterior premature dental contact or an anterior open bite is suggestive of bilateral condylar or angle fractures Posterior open bite is common with anterior alveolar process or parasymphyseal fractures,Unilateral open bite is suggestive of an ipsilateral angle and parasymphyseal fracture Retrognathic occlusion is seen with condylar or angle fractures Condylar neck fx are assoc with open bite on opposite side and deviation of chin towards the side of the fx.,Physical Exam - Occlusion,Bilateral angle fx can cause an open bite,Unilateral open bite may be the result of ipsilateral angle and parasymphyseal fractures,Malocclusion,Physical Exam, Cont,Anesthesia of lower lip is “pathognomonic” of a fracture distal to the mandibular foramen The converse is not true: not all fractures distal to the mandibular foramen have mental n. anesthesia Trismus of less than 35mm also highly suggestive of mandibular fracture,Physical Exam, Cont,Inability to open the mandible suggests impingement of the coronoid process on the zygomatic arch Inability to close the mandible suggests a fracture of the alveolar process, angle, ramus or symphysis,Lacerations and Ecchymosis,Mandibular fractures can often be directly visualized beneath facial lacerations. Lacerations should be closed after definitive therapy of the fracture Ecchymosis is diagnostic of symphyseal fractures,Palpation,The mandible should be palpated with both hadns, with the thumb on the teeth and the fingers on the lower border of the mandible. Slowly and carefully place pressure, noting the characteristic crepitation of a fracture,Radiographic Exam,Panorex shows the entire mandible, but requires the patient to be upright. It also has particularly poor detail of the TMJ and medial displacement of the condyles AP - ramus and condyle Submental - symphysis CT - condylar fractures,Radiographic Exam, Cont.,Lateral oblique radiograph Occlusal view Periapical view Reverse Townes view Temporomandibular joint, including tomograms,Evaluation - Panorex,Evaluation - Mandible films,The lateral oblique view of the mandible is helpful in diagnosis ramus, angle and posterior body fractures.,Mandible occlusal view, discrepancies in the medial and lateral position of the body fractures and anteroposterior displacement of the symphysis can be shown.,Computed tomography scan is ideal for condylar fx.,Associated Injuries,Cervical spine injury,Cervical spine injury,Lateral radiograph of cervical spine fracture (large arrow) in association with mandibular angle fracture (small arrow),General Principles of Therapy,A. General physical status B. Dental injuries C. “Classical” indications for closed reduction D. “Classical” indications for open reduction E. Contraindications to MMF,General Principles of Treatment,The general physical status should be thoroughly evaluated. 40% associated with significant injury, 10% of which are lethal Cerebral contusion is common ABCs! Almost never emergent,General Principles, Cont,Dental injuries Fractured teeth can become infected and cause malunion. Extraction necessary if root of tooth is fractured A tooth that is intact but in the line of the fracture can be left in place and protected by antibiotics may need extraction later,General Principles, Cont,Reestablishment of occlusion is the primary goal Fractured teeth may jeopardize occlusion Mandibular cuspids are cornerstone of fx. Prophylactic antibiotics With multiple facial fractures, mandibular fractures are treated first.,General Principles, Cont,Intermaxillary fixation time should vary according the type, location, number, and severity of the Fx. Nutritional needs monitored postoperatively. Most Fx. can be treated by closed reduction.,Indications for closed reduction,Nondisplaced favorable fractures. Grossly comminuted fx. Fx. exposed by significant loss of overlying soft tissues. Edentulous mandibular fx.,Indications for closed reduction,Mandibular fx. in children with developing dentitions Coronoid process fractures. Condylar fractures.,Indications for open reduction,Displaced unfavorable fractures through the angle of the mandible. Displaced unfavorable fx. of the body or parasymphyseal region Multiple fx. Displaced bilateral condylar fx. Edentulous mandible with severe displacement of fx. fragments.,Indications for open reduction,Edentulous maxilla opposing a mandibular fx. Delay of treatment and interposition of soft tissue between noncontacting displaced fx. fragments. Malunion. Special systemic conditions contraindicating intermaxillary fixation.,Treatment options,No treatment Soft diet Maxillomandibular fixation Open reduction - non-rigid fixation Open reduction - rigid fixation External pin fixation Lag screw, DCP,Maxillomandibular fixation,Maxillomandibular fixation,Maxillomandibular fixation,Alternative - Ivy loops,Ivy loops are effective for certain types of fx.,Open reduction - nonrigid fixation,Open reduction - nonrigid fixation,Various wire ligature shape: 1. simple ligature; 2. combined simple and figure-of-eight ligature; 3. brons wiring; 4. double ligature.,Open reduction - Rigid fixation,Open reduction - Rigid fixation,Ideal lines for miniplate osteosynthesis of mandibular body,Mandible showing miniplates applied to stabilize typical fractures,Tension curve,Compression curve,External Fixation,Lag screw,Treatment Techniques,A. Closed reduction of the dentulous patient B. Closed reduction of the partially dentulous patient C. Closed reduction of the edentulous patient D. Open reduction and fixation-osteosynthesis E. Open reduction and rigid fixation,Surgical approaches,Submandibular approach Preauricular approach Retromandibular approach Endaural approach Intraoral access Symphysis and parasymphysis Body,angle and ramus,The submandibular and preauricular incisions,Retromandibular incision,Closed Reduction,Grossly comminuted fractures Significant tissue loss Edentulous mandibles Fractures in children Condylar fractures Contraindicated in SzDo, psych, and compromised pulmonary function,Closed Reduction of the Edentulous Patient,Dentures with circum wires and screws Fabricated acrylic plates (Gunning Splints) In fractures of both the mandible and maxilla, circumzygomatic and circum-mandibular wires should be tied together to prevent telescoping of maxilla,Closed Reduction of the Dentulous Patient,Erich Arch Bars. Can lead to periodontal infalmmation. Avoid fixating incisors, as these teeth are moved by the wires Ivey loops,Splint fabrication,Splint fabrication,Splint fabrication,Application of Splints,Application of Splints,Gunning splint used for edentulous mandibular fx.,Denture preparation,Closed Reduction of the Partially Edentulous Patient,Partials and circum wires or screws Acrylic partials with incorporated arch bar wires,Open Reduction,Displaced, unfavorable fractures of angle Displaced unfavorable fractures of the body or parasymphysis, as these tend to open at the inferior border, leading to malocclusion Multiple fractures of facial bones Displaced, bilateral condylar fractures,Open Reduction and Osteosynthesis,Simpler than rigid fixation MMF still required Useful in angle, parasymphyseal fractures,ORIF,Performed with compression plates and lag screws MMF generally not required Eccentrically placed holes and screws placed at angles “compress” the bone,Treatment options for dentate patients,Special Considerations Open reduction of Condylar Fx.,Special Considerations -Condylar Fx.,Wire osteosynthesis,Special Considerations -Condylar Fx.,Messer technique forwire osteosynthesis,Special Considerations -Condylar Fx.,K wire,Special Considerations -Condylar Fx.,Axial anchor screw,Special Considerations -Condylar Fx.,Plate and screw fixation,Special considerations - Pedi,Deciduous teeth vs. permanent Fractures with deciduous dentition can be treated with MMF for 2-3 weeks. Rigid techniques can harm the tooth bud. Growth center The most feared complication of a pedi mandible fx is ankylosing of the TMJ with impact on jaw growth that causes severe facial deformity- prevent with weekly mobilization,Special considerations - pedi,Special considerations - pedi,Complications,Complications,Socioeconomic condition greatly affects outcome Infection - In a prospective study by James of 422 fx -infection rate was 7% of which 50 % were associate with fx or carious teeth, of the 177 fx requiring ORIF, 12 % became infected,Complications,Delayed healing(3%) and nonunion(1%) most common cause in infection second most common cause is noncompliance inadequate reduction, metabolic or nutritional deficiency can play a role Nerve paresthesias (Inf. Alveolar nerve) occur in 2% Malocclusion and malunion TMJ prob