Semi-quantitative study of magnetic resonance imaging features of disc-condylar complex in patients with anterior disc displacement without reduction of temporomandibular joint

To investigate the differences in magnetic resonance imaging (MRI) characteristics between anterior disc displacement with reduction(ADDWR) and anterior disc displacement without reduction (ADDWoR) of the temporomandibular joint (TMJ) by semi-quantitative analysis of the disc-condylar complex. Reliable imaging markers were selected to predict ADDWoR. The risk factors of ADDWoR were analyzed by univariate and multivariate logistic regression methods, and the receiver operating curves(ROC) were plot to evaluate the diagnostic ability. There were statistically significant differences in disc shape, displacement degree, condylar shape, bone change, position and joint effusion between the two groups(p<0.05). Univariate logistics showed that fold-curved articular disc, degree of ADD, condylar bone change, beak condyle, central condyle and effusion grades were all related factors in the diagnosis of ADDWoR. Multivariate logistic showed fold-curved articular disc, the degree of ADD and the grade of joint effusion were independent factors for the diagnosis of ADDWoR. The area under ROC curve for ADD-degree and joint effusion analysis for the prediction of ADDWoR was 0.909 and 0.745,respectively. Based on semi-quantitative analysis of MRI signs of disc-condylar complex, it can effectively evaluate the influencing factors of ADDWoR and provide imaging reference for clinical disease prediction of temporomandibular joint (TMJ) patients.