Osteochondroma of the right coronoid process (Jacob disease): a case report.

Oscar Jacob was the first to describe osteochondroma of the coronoid process, naming it "Jacob disease." Jacob disease rarely occurs in the oral and maxillofacial regions. The tumor usually grows progressively, leading to a mushroom-shaped enlargement of the process, and a joint-like structure is found between the coronoid process and the inner aspect of the zygomatic arch. Most of these lesions grow like a mushroom on, and do not destroy, the coronoid process. The major symptoms include restricted mouth opening and morphological changes to the zygoma. The authors present a case report on an 18-year-old male patient with pain in the right zygoma. Interincisal maximum mouth opening was 51 mm. An intraoral coronoidectomy was performed.