A 22-year-old man strikes his chin on a handlebar. He has pain and swelling over the left preauricular region, bleeding from the left ear, and deviation of the chin to the left on opening the mouth. There is premature occlusion of the molars on the right side. The most likely diagnosis is:

• A Left temporomandibular joint dislocation
• B Left condylar process fracture ✓
• C Right parasymphyseal fracture
• D Left zygomaticomaxillary complex fracture

Explanation

A blow to the point of the chin transmits force to both condyles. In unilateral condylar fracture, the ramus shortens on that side so the midline deviates toward the fractured side on mouth opening, and the molars on the intact side contact prematurely while an open bite appears on the fracture side. TMJ dislocation does not produce preauricular bleeding or molar prematurity. Bleeding from the ear suggests condylar head penetration into the middle ear fossa.

Reference: Peterson's Principles of Oral and Maxillofacial Surgery, 3rd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.