Magnetic resonance changes in the temporomandibular joint in ankylosing spondylitis

Objective. To evaluate temporomandibular joint (TMJ) involvement of patients with severe ankylosing spondylitis (AS) using magnetic resonance imaging (MRI). Methods. All patients with severe cervical involvement, defined as occiput-wall distance ≤ 3 cm and/or < 10°of cervical flexion, from a consecutive cohort of 103 patients with AS were included in the study. Patients completed a questionnaire designed to evaluate symptoms of temporomandibular disorder (TMD). Open and closed mouth sagittal T1 weighted MRI sequences of the right TMJ was performed in all patients. MR images were specifically reviewed for condylar position and morphology, as well as articular disc position and morphology. Results. Eleven patients were identified and included in the study. Temporomandibular symptoms were absent in 4 (37%), a single symptom was present in one (9%), 2 symptoms in one (9%), 3 symptoms in 3 (27%), and 4 symptoms in 2 (18%). Ten of the 11 patients had abnormalities on MR, including condylar alterations such as abnormal shape, erosions, and reduction in translation. Disc alterations were present in 8 patients and osteophytes in 7. Two patients were graded as having mild abnormalities, another 2 as moderate, and the remaining 6 were considered grossly abnormal. In 2 patients there were changes compatible with ankylosis of the right TMJ. Conclusion. Although it is uncommon for patients to complain spontaneously about TMD symptoms, involvement of the TMJ in patients with severe AS appears to be frequent and, in some, severe. The effect of TMJ involvement on the overall well being and nutritional status in patients with AS remains to be determined.