Hyperplasia of the coronoid process in patients with ankylosing spondylitis (Bechterew disease).

Although involvement of the temporomandibular joint in patients with ankylosing spondylitis (AS, Bechterew disease) has been described previously, hyperplasia of the mandibular coronoid process in those patients has not been reported yet. Case notes were studied, and records were made of age, sex, clinical symptoms, radiography, and treatment in all patients with a confirmed diagnosis of coronoid hyperplasia presenting at the Department of Oral and Maxillofacial Surgery, University of Bonn, between 1995 and 2007. Sixteen cases of coronoid hyperplasia were recruited, of which 12 were bilateral and 4 were unilateral. Four patients had AS, 3 of them were HLA-B27-positive. Temporomandibular joint symptoms are frequently seen in patients with AS. Nevertheless, it must be considered that a limitation of jaw mobility in those patients might also be caused by an elongation of the mandibular coronoid process.