Abstract
Bilateral enlargement of the coronoid process of the mandible, associated with limited mouth opening, is rare.
This report describes a case of bilateral hyperplasia of the mandibular coronoid process in a 13-year-old boy. Trismus was diagnosed on a dental examination at school.
Panoramic radiography showed that both coronoid processes extended above the zygomatic arch. His maximum mouth opening was 27mm (interincisal distance).
Coronoidotomy was performed via an intraoral approach under general anesthesia, and continuous mouth-opening training was done after surgery. Thirty-four months after the operation, the maximum interincisal distance was maintained at 44mm. The mandibular coronoid process was remodeled posteriorly to prevent interference with mouth opening.
