Coronoid hyperplasia is a rare condition that is characterized by enlargement of the coronoid process. It causes painless progressive limitation of the mouth opening because of the impaction of the coronoid process on the posterior aspect of the zigomatic bone. It is frequently seen in males during pre-pubertal age. The etiological factors described in literature are; TMJ dysfunction, TMJ hipomobility, hormonal stimulus, genetic inheritance or idiopathic. Panoramic Films and CT Scans are used to confirm and characterize the presence and extent of coronoid hyperplasia. Generally the coronoid process exceeds the zigomatic arch. The treatment consists in surgical coronoidectomy and postoperative physical therapy. The aim of this study is to present five pediatric cases of coronoid hyperplasia; their treatment and long term follow up.

The five patients described have different coronoid hyperplasia etiologies, some have coronoid hyperplasia alone and others are associated to syndromes. Coronoidectomy is the treatment for coronoid hyperplasia. Active physical therapy is crucial to maintain an adequate mouth opening in time.

The TMJ and coronoid process must be studied in every patient who has a severe mouth opening limitation.

Conflict of interest: None declared.