title: Mouth opening limitation caused by coronoid hyperplasia: a report of four cases.
abstract: Coronoid process hyperplasia is a rare condition that causes mouth opening limitation, otherwise known as trismus. The elongated coronoid processes impinge on the medial surfaces of the zygomatic arches when opening the mouth, which limits movement of the mandible and leads to trismus. Patients with trismus due to coronoid process hyperplasia do not have any definite symptoms such as temporomandibular joint pain or sounds upon clinical examination, and no significant abnormal signs are observed on panoramic radiographs or magnetic resonance images of the temporomandibular joint. Thus, the diagnosis of trismus is usually very difficult. However, computed tomography can help with the diagnosis, and the condition can be treated by surgery and postoperative physical therapy. This paper describes four cases of patients who visited our clinic for trismus and were subsequently diagnosed with coronoid process hyperplasia. Three were successfully treated with a coronoidectomy and postoperative physical therapy.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Gangnam Severance Hospital, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, Gangnam Severance Hospital, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Jin-Hyeok
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, Yongin Severance Hospital, Yonsei University College of Dentistry, Yongin, Korea.
authors.forename: Hak-Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, Gangnam Severance Hospital, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Jong-Ki
authors.initials: JK
authors.lastname: Huh
keywords: Diagnosis; Hyperplasia; Mandible; Temporomandibular joint disorders; Trismus