Diagnostic accuracy of ultrasonography compared with magnetic resonance imaging in diagnosing disc displacement of the temporomandibular joint: A systematic review and meta-analysis

Statement of problem Diagnosing temporomandibular disorders without an adjunctive chairside diagnostic tool has made the management of temporomandibular disorders challenging and subjective. The use of magnetic resonance imaging, considered the standard imaging modality, is hindered because of high cost, a long learning curve, availability, and a longer examination time. Purpose The purpose of this systematic review and meta-analysis was to determine whether ultrasonography could be a chairside tool to help clinicians diagnose disc displacement in temporomandibular disorders. Material and methods An electronic search was conducted of the PubMed (including MEDLINE) and Cochrane Central database and the Google Scholar search engine for articles published from January 2000 to July 2020. Studies were chosen based on the inclusion criteria, which included the diagnostic technique's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with respect to imaging the displacement of the articular disc. The quality assessment of diagnostic accuracy studies (QUADAS- 2) tool was applied to assess the risk of bias for the included studies. The Meta-Disc 1.4 and RevMan 5.3 software program were used to conduct the meta-analysis. Results Seventeen articles were included in this systematic review, and a meta-analysis of 14 articles was done after applying the inclusion and exclusion criteria. None of the included articles were considered to have applicability concerns; however, 2 articles had a high risk of bias. The sensitivities and specificities for the different selected studies vary substantially from 21% to 95% with a good pooled sensitivity estimate of 71% while the specificities varied from 15% to 96% with a good pooled specificity estimate of 76%. Conclusions This systematic review and meta-analysis suggested that ultrasonography may have clinically acceptable diagnostic accuracy in diagnosing disc displacement of the temporomandibular joint, allowing the treatment of patients with temporomandibular disorders with greater assurance and success. Additional training in the operation and interpretation of ultrasonography is required to reduce the learning curve and make the use of ultrasonography relevant, straightforward, and routine in dentistry to supplement clinical examination and diagnosis in patients with suspected disc displacement of the temporomandibular joint. The evidence acquired needs to be standardized, and further research is required to provide stronger evidence.