Ultrasonography for Detection of Disc Displacement of Temporomandibular Joint: A Systematic Review and Meta-Analysis

PurposeTo assess the diagnostic efficacy of ultrasonography in detecting disc displacement of the temporomandibular joint.Materials and MethodsMEDLINE (using OVID, 1950 to April 2011), EMBASE (1980 to April 2011), and the Chinese Biomedical Literature Database (1978 to April 2011) were searched electronically. In addition, relevant journals and reference lists of the included studies were manually searched for any eligible studies on diagnostic accuracy. Two authors performed the study inclusion, data extraction, and risk of bias assessment in duplicate. Meta-analysis was performed with MetaDisc 1.4.ResultsFifteen studies were included in this meta-analysis; 6 studies had a low risk of bias, 6 studies an unclear risk, and 3 studies a high risk. Meta-regression indicated that the detected results were not influenced by the types of ultrasonography, image dimensions, types of transducer, and ultrasonic image of the disc (P > .05). The Q* values of ultrasonography for the closed- and open-mouth positions were 0.79 and 0.91, respectively. The diagnostic efficacy of disc displacement with reduction had a sensitivity of 0.76, a specificity of 0.82, a positive likelihood ratio of 3.80, a negative likelihood ratio of 0.36, a diagnostic odds ratio of 10.95, an area under the curve of 0.83, and a Q* of 0.76. The diagnostic efficacy of disc displacement without reduction had a sensitivity of 0.79, a specificity of 0.91, a positive likelihood ratio of 80.5, a negative likelihood ratio of 0.25, diagnostic odds ratio of 36.80, an area under the curve of 0.97, and a Q* of 0.92.ConclusionsThe diagnostic efficacy of ultrasonography is acceptable and can be used as a rapid preliminary diagnostic method to exclude some clinical suspicions. However, positive ultrasonographic findings should be confirmed by magnetic resonance imaging. Also, the ability of ultrasonography to detect lateral and posterior displacements is still unclear. More high-quality studies are needed to assess the diagnostic efficacies of some specific ultrasonographic methods. Standards and criteria for ultrasonographic techniques in the diagnosis of disc displacement should be established in the future.