The role of ultrasonography in the diagnosis of temporomandibular joint disc displacement and intrarticular effusion

The aim of this work is to conduct a preliminary study to investigate the usefulness of ultrasonography (US) in the study of temporomandibular joint (TMJ), comparing ultrasonographic diagnosis of joint effusion and disc displacement with those based on an accurate clinical examination. METHODS: Participants in this study were 47 consecutive patients complaining for TMJ problems. All 94 TMJs were evaluated to detect the presence of intra-articular effusion and disc displacement by means of 2 diagnostic instruments: a standardized clinical assessment based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC-TMD) at the Section of Prosthetic Dentistry, and an ultrasonographic investigation conducted by a blinded operator at the Operative Unit of the Department of Rheumatology, Univesity of Pisa, Italy. Agreement between the two diagnostic techniques has been evaluated by means of Cohen's K test. RESULTS: Ultrasonography showed a good agreement with clinical assessment for the diagnosis of both intra-articular effusion (percentage of agreement 80%; K=0.611) and disc displacement (agreement 81.9%; K=0.572). CONCLUSION: When compared to a standardized clinical assessment, ultrasonographic technique showed a good diagnostic capability to detect TMJ intra-articular effusion and disc displacement. Within all the limitations of this study, it can be suggested that ultrasonography could represent a promising imaging technique in the study of temporomandibular joint.