Bilateral mandibular coronoid hyperplasia causing trismus – a case report

Abstract Mandibular coronoid process hyperplasia is a rare developmental condition. It commonly presents with progressive restriction of mouth opening, due to the impingement of the enlarged and elongated coronoid process on the distal aspect of the zygomatic arch during mandibular movement. It may present unilaterally or bilaterally. Surgical intervention to improve opening is advocated in cases with significant functional impairment, followed by post‐operative physiotherapy. A case of bilateral coronoid process hyperplasia in a 28‐year‐old man treated with bilateral coronoidectomy, with subsequent post‐operative relapse in degree of opening successfully treated via manipulation under intravenous sedation is presented.