ABSTRACT
BACKGROUND: This case report discusses the unusual presentation of limited mouth opening as a result of bilateral coronoid process hyperplasia. CASE PRESENTATION: A 14.5-year-old male patient of white Caucasian ethnicity presented with limited mouth opening, mandibular asymmetry, and dental crowding. Investigations confirmed bilateral coronoid process hyperplasia and management involved bilateral intraoral coronoidectomy surgery under general anaesthesia, followed by muscular rehabilitation. Mouth opening was restored to average maximum opening within 4 months of surgery. CONCLUSION: Limited mouth opening is a common presentation to medical and dental professionals. The rare but feasible diagnosis of coronoid impingement syndrome should not be overlooked.