MR imaging of the TMJ

Abstract

In clinical work we have observed decreased signal intensity from the retrodiskal tissue in some patients with temporomandibular joint disk displacement. The frequency and clinical significance of this observation is unknown. To document the frequency and to assess its clinical significance we analyzed magnetic resonance images of the temporomandibular joints of 69 patients with temporomandibular joint displacement and 28 asymptomatic volunteers. All the subjects had a clinical examination, and their level of pain was recorded. Decreased signal intensity from the retrodiskal tissue was seen in 16 joints in the patients (12%). None of the asymptomatic volunteers exhibited this feature. It was seen in one joint with disk displacement with reduction, in nine joints with disk displacement without reduction, and in six joints with disk displacement without reduction and arthrosis. It was not seen in any joint with superior disk position. We could not appreciate an association between the decreased signal intensity from the retrodiskal tissue and the level of pain because this feature was seen in both painfree and painful joints. It was concluded that decreased signal intensity from the retrodiskal tissue was most frequently associated with later stages of disk displacement and its clinical significance remains unclear because there was no appreciable correlation to patient symptoms of pain.