Diagnostic value of ultrasonography for the detection of disc displacements in the temporomandibular joint: a systematic review and meta-analysis

OBJECTIVES: The aim was to assess the added diagnostic value of ultrasonography (US) for establishing the presence or absence of disc displacements (DDs) in temporomandibular joints (TMJs). MATERIALS AND METHODS: Pubmed and EMBASE were searched electronically to identify diagnostic accuracy studies that assessed the diagnostic value of US for the diagnosis of DD, using Magnetic resonance imaging (MRI) as the reference standard. Meta-analyses were performed with Metadisc 1.4 and RevMan 5.3. RESULTS: A total of 16 studies qualified for meta-analyses. For the diagnosis of DD at closed mouth position (DD-CM) and DD at maximum mouth-opening position (DD-MMO), the added values of a positive result with US for ruling in DD-CM and DD-MMO were 22 and 41%, while those of a negative result with US for ruling out DD-CM and DD-MMO were 30 and 20%. For the diagnosis of DD with reduction (DDWR) and DD without reduction (DDWoR), the added values of a positive result in US for ruling in DDWR and DDWoR were 35 and 41%, while those of a negative result in US for ruling out DDWR and DDWoR were 21 and 27%. CONCLUSIONS: Using MRI as reference standard, the added values of both positive predictive values and negative predictive values of US for ruling in and ruling out DDs are sufficient in the decision-making in dental practice. CLINICAL RELEVANCE: US can be a good imaging tool to supplement clinical examination findings in patients with suspected DDs. Combined static and dynamic examinations using high-resolution US should be preferred.