Fig. 5.

Positive and negative predictive values of ultrasonography compared to the prevalences of disc displacement at closed mouth position (DD-CM), disc displacement at maximum mouth opening (DD-MMO), disc displacement with reduction (DDWR), and disc displacement without reduction (DDWoR) for each included study. Red circles represent positive predictive values of US of the included studies and green circles represent negative predictive values of US of the included studies. (a DD-CM, b DD-MMO, c DDWR, d DDWoR). The red diagonals represent the positive predictive value were the same as prevalence, and there was no added value for ruling in the DDs at this diagonal. The green diagonals represent the negative predictive value were the same as the compliment of prevalence (1—prevalence), and there was no added value for ruling out the DDs at this diagonal