Zygomatico-Coronoid Ankylosis: A Case Report

Extra-articular ankylosis resulting from bony union between the coronoid process and the zygoma is very rare. It may result from facial fractures caused by gunshots, treated or untreated facial fractures or may arise as an extension of intracapsular ankylosis. We report a case of ankylosis between the coronoid process and the zygomatic arch in a 33-year-old Black male. The bony ankylosis was the result of a 2 year old untreated zygomatic arch fracture. Ankylosis developed secondary to heterotopic bone formation following trauma. The patient was treated by intra-oral coronoidectomy, followed by physiotherapy for three months. He returned for review one year later with a mouth-opening of 40 mm and a stable occlusion.