A question frequently asked in the clinical practice of the professional who treats temporomandibular joint disorders (TMJD) is 'To make the cost/benefit ratio worthwhile for the patient, when should I request a temporomandibular joint (TMJ) computed tomography (CT) or magnetic resonance imaging (MRI)?' To evaluate the evidence of the efficacy of CT and MRI in the diagnosis of disc displacement, local inflammatory disorders, and arthrosis of the TMJ at therapeutic efficacy level, PubMed and Cochrane literature searches with specific indexing terms and a hand search were made. From the retrieved titles and abstracts, three examiners selected publications on the basis of predetermined inclusion and exclusion criteria. Data were extracted from the selected publications using a previously established protocol. Publications considered relevant were interpreted with the aid of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool and publications that critically evaluate systematic reviews. The literature search yielded 584 titles and abstracts, of which 257 were selected and read in full text. One study was judged relevant. This study evaluated evidence of the efficacy of MRI in the diagnosis of disc position and configuration, disc perforation, joint effusion, and osseous and bone marrow changes in the temporomandibular joint, but no publication reported diagnostic thinking efficacy or therapeutic efficacy. In conclusion, the absence of studies on the therapeutic efficacy of MRI and CT on TMJD reinforces the need for investment in decision-making studies; meanwhile, sectional imaging tests should be prescribed with caution, especially when health budgets are limited.

© 2010 Blackwell Publishing Ltd.