Condylar Fracture of the Mandible

Condylar fracture of the mandible is a fracture of the condylar process, accounting for about 25 to 35% of mandibular fractures. It is usually the result of an indirect blow to the chin, symphysis or body that transmits force up the ramus.

Fractures are classified by site: intracapsular (head), condylar neck and subcondylar (base), and by displacement or dislocation of the fragment. They are often bilateral or accompany a symphyseal or parasymphyseal fracture.

Pathophysiology. The condylar neck is the weakest part of the mandible. The lateral pterygoid pulls the proximal fragment medially and forward, and the masseter and temporalis shorten the ramus.

Loss of ramus height produces premature contact on the fractured side and an open bite on the opposite side. Intracapsular fractures and children are at risk of ankylosis.

Pre-auricular pain and swelling, deviation of the jaw to the affected side on opening, limited opening and malocclusion with premature molar contact on the affected side and an open bite on the other side. Bilateral fractures give an anterior open bite and a retruded chin. Bleeding from the ear canal, haematoma and absence of condylar movement on palpation in the ear canal may be present.

Check associated injuries: other mandibular fractures, head injury, cervical spine and facial fractures. Airway compromise is rare except with bilateral or comminuted injuries.

Airway threat, associated mandibular or midface fractures, head injury, ear canal laceration with cerebrospinal fluid leak or facial nerve palsy need urgent assessment.

• Panoramic radiograph and posteroanterior mandible view for initial assessment. CT of the facial bones with 3D reconstruction, the preferred test for the level of fracture, displacement and dislocation.
• Occlusion assessment and measurement of opening in millimetres.
• Cervical spine and head assessment depending on the mechanism.
• Examination of the facial nerve, the ear canal and the lower lip sensation.
• Tetanus status.

Differential diagnosis.

• Temporomandibular joint dislocation
• Haemarthrosis and joint contusion without fracture
• Other mandibular fracture (angle, body, symphysis)
• Zygomatic complex or arch fracture with trismus
• Fracture of the temporal bone or external auditory canal
• Pre-existing TMJ disorder
• Condylar resorption

• Closed (conservative) treatment is used in most undisplaced, minimally displaced, intracapsular and paediatric fractures: soft diet, analgesia, and elastics to direct the bite or a short period of intermaxillary fixation for 1 to 2 weeks, followed by early mobilisation and physiotherapy. Prolonged fixation increases the risk of ankylosis.
• Open reduction and internal fixation is preferred for adults with displaced or dislocated condylar neck or base fractures, particularly with loss of ramus height. Absolute indications: displacement into the middle cranial fossa, inability to obtain the occlusion by closed means, lateral extracapsular displacement, and open wound or foreign body. Relative indications: bilateral fractures, other midface fractures that need a stable base, and a patient who cannot tolerate fixation. Use a retromandibular or preauricular approach with plates, taking care of the facial nerve.
• Fractures of the head are treated conservatively, or with fixation for large displaced fragments by specialist teams.
• Antibiotics: for compound fractures, amoxicillin with clavulanic acid 1.2 g intravenously every 8 hours for the first 24 hours, then oral 625 mg three times daily to complete 5 days when infection or contamination exists. For clean operative fixation, a single perioperative dose of cefazolin 2 g intravenously (3 g if over 120 kg) is enough. Clindamycin 600 mg intravenously in penicillin allergy. Reduce the dose of amoxicillin with clavulanic acid when eGFR is under 30.
• Tetanus toxoid 0.5 mL intramuscularly if vaccination is incomplete or the last dose was over 10 years ago, and tetanus immunoglobulin 250 IU intramuscularly (500 IU after 24 hours or heavy contamination) when status is unknown or incomplete.
• Analgesia: paracetamol 1 g every 6 hours (maximum 4 g daily) with ibuprofen 400 mg every 8 hours with food when appropriate. Chlorhexidine 0.2% mouthwash 10 mL twice daily.
• Physiotherapy from week 1 to 2 with mouth opening exercises to prevent ankylosis.
• Children: conservative treatment with early mobilisation, and long term review of growth because of the risk of ankylosis and asymmetry.

Monitoring. Review at 1, 2, 6 and 12 weeks for occlusion, opening range and deviation, with radiographs at 6 weeks. Check for malocclusion, joint pain, facial nerve function and growth disturbance.

Referral and escalation. Refer to oral and maxillofacial surgery. Urgent referral for airway threat, multiple fractures, open fractures, head injury or facial nerve palsy.