Bone formation after resection of unilateral hyperplasia of the mandibular coronoid process: Report of a case

Abstract

This paper describes a rare case of bone formation after resection for unilateral hyperplasia of the mandibular coronoid process. A 13-year-old boy was referred to our clinic for trismus. His maximum mouth opening was 13 mm (interincisal distance). Radiographic examination showed that the inner surface of the zygomatic arch interfered with the left coronoid process.
Coronoidectomy was carried on the left side via an oral approach under general anesthesia. After coronoidectomy, the amount of interincisal mouth opening was 37 mm. In addition, incision and abrasion of the bilateral masseteric fascia was carried out, and an interincisal mouth opening of 43 mm was achieved.
New bone formation was noted at the site of coronoidectomy after three months. The new bone had almost not changed in size and had not made connection with the mandible. Following jaw-stretching exercises, the patient had an interincisal opening of 32 mm after 34 months.