[Ankylosis of the temporomandibular joint: a rare manifestation of ankylosing spondylitis].

INTRODUCTION: The ankylosing spondylitis is a chronic inflammatory rheumatoid disease with predilection in the axial structures. The temporomandibular joint (TMJ) is involved in 10 to 24% of cases. Ankylosis of the TMJ is exceptional, only 11 cases being reported to date. OBSERVATION: A 48-year-old patient had been followed since 1987 for severe ankylosing spondylitis. The patient, known to be positive for tissue antigen HLA B27, was admitted for limitation of mouth opening. At physical examination, mouth opening was reduced to 1cm with no mandibular movements and a stiffness of the cervical spine in flexion. Computed tomography of the TMJs highlighted a bilateral lesion with ankylosis of the left joint and of C1-C2. Surgical treatment consisted in block resection of the two TMJs using a cartilaginous rib. With a follow up of 9 months, results have been satisfactory. DISCUSSION: Complementary explorations should be undertaken in ankylosing spondylitis patients with clinical symptoms suggestive of TMJ lesions in order to establish the diagnosis and initiate treatment and avoid the development of ankylosic forms.