Temporomandibular joint soft-tissue pathology, II: Nondisc abnormalities.

The most important objective in a magnetic resonance imaging (MRI) study of the temporomandibular joint (TMJ) is to determine the location of disk, because the presence of a displaced disk is a critical sign of TMJ dysfunction. However, a high frequency of disk displacement appears in asymptomatic volunteers; thus, other MRI indirect signs of TMJ dysfunction can help in the diagnosis. Further studies using the latest MRI techniques allow a better understanding of the sources of joint pain and the discrepancy between imaging findings and patient symptoms. Evaluation of other MRI signs such as the presence of joint effusion, the rupture of retrodiscal ligaments, or the thickness of the attachment of the external pterygoid muscle can be used as indirect early signs of TMJ dysfunction, before osteoarthritic changes lead to a more advanced stage of the dysfunctional spectrum. In this article we show those MRI indirect signs of TMJ dysfunction, providing more reasons to separate anatomic variants of healthy individuals from a real internal derangement.