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17 Cards in this Set
- Front
- Back
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Mandible fracture causes
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assault, MVA, sports, gunshot wounds
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Most common mandible fracture sites
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condylar neck
angle parasymphysis |
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Favorable vs unfavorable fractures
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Favorable: vector forces from muscles pull fragments together
Horizontally unfavorable: masseter and temporalis pull apart Vertically unfavorable: anterior muscles and pterygoid muscles pull fragments apart |
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Anterior mandible muscles
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-weaker force
-mylohyoid, geniohyoid, genioglossus, platysma, ant digastric -depresses and retracts (opens mandible) |
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Posterior mandible muscles
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-stronger force
-temporalis: raises and retracts -masseter: raises and retracts -medial pterygoid: raises -lateral pterygoid: DEBRESSES, protrudes |
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Bite classification
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Class I: mesiobuccal cusp of maxillary first molar lies in the buccal groove of mandibular first molar
Class II: overbite Class III: underbite |
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Indications to remove tooth
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-Tooth in fracture line interfering with occlusion
-infected tooth in fracture line -fractured, nonviable teeth Disadvantages: nigus for infection and point of weak fixation |
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MMF
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-provides tension band
-arch bars stronger than ivy loops -requires intact maxilla -removed after 2-8 weeks (3-4 kids, 4-6 adults, elderly 8, condylar 1-2 weeks) -Complications: airway compromise, TMJ, aspiration |
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ORIF mandible
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-indications: comminuted fractures, poor pulmonary reserve, nocompliant, bilateral fractures
-MMF priro to ORIF -Transoral: avoids marg injury, access to symphyseal, parasymphyseal, body -External: for more posterior or severly comminuted fractures |
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Coronoid/greenstick/unilateral non-displaced fractures
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soft diet
analgesics oral antibiotics follow-up |
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Fracture with highest complication rate
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angle bc of location posterior to dentition, thin-walled bone, vector forces from masseter muscle
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Rarest mandible fracture
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ramus: protected by masseter
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Pediatric mandible fractures
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-conservative management if possible: soft diet, obs
-MMF for 3 weeks for open bite deformity -may need skeletal wires (deciduous teeth hard to wire) -subcondylar fractures more prone to ankylosis and mandibular growth abnormalities |
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Bilateral condylar neck fractures
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risk of airway compromise
anterior bite deformity 2-3 week MMF encourage movement of jaw to prevent TMJ ankylosis |
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Edentulous patients
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have atrophic mandibles
ORIF with plates |
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Surgical complications
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-chin/lip hypersthesia from inferior alveolar or mental n (most common comp)
-osteomyelitis -malunion -nonunion: failure of bone to produce osteogenic tissue (excise fibrous tissue and nonviable bone) -plate exposure -marg injury -necrosis of condylar head (aseptic necrosis) |
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TMJ ankylosis
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-potential complication of jaw fracture
-unable to upen jaw beyone 5mm -in kids may cause facial deformities with growth -treat wtih passive jaw opening exercises |
