Hyperplasia of the Coronoid Process

Objective: To review the morphology, aetiology, clinical symptoms, diagnosis, and therapy of true coronoid hyperplasia.Patients and Methods: The record of all patients with a confirmed diagnosis of mandibular coronoid hyperplasia presenting to the Department of Oral and Maxillofacial Surgery, University of Bonn, Bonn, Germany, between 1995 and 2004 were reviewed and details of age, sex, clinical symptoms, radiography, and treatment were noted. The results of this series were compared with those previously reported in the literature by meta-analysis.Results: Fourteen new patients from the Department of Oral and Maxillofacial Surgery and 101 patients with coronoid hyperplasia reported in the literature were included. There were 96 patients with bilateral coronoid hyperplasia and 19 patients with unilateral coronoid hyperplasia. The average age at diagnosis was 23.7 years. The main presenting symptom was progressive limitation of mouth opening. All 14 patients from the Department of Oral and Maxillofacial Surgery underwent coronoidectomy and postoperative physiotherapy, with an improvement in mouth opening to more than 30 mm for 86% of patients. In the previously published series, 95% of patients underwent coronoidectomy and 5% had coronoidotomy; 65% of patients were reported to have undergone postoperative physiotherapy with 73% improved mouth opening.Conclusion: Compared with the relatively disappointing results for mouth opening in previous studies, the treatment approach at the the Department of Oral and Maxillofacial Surgery underlines the superiority of coronoidectomy over coronoidotomy and the importance of dynamic physiotherapy with a jaw rehabilitation system to reduce post-surgical fibrosis and to maintain stable long-term results.