Correlation Between Condylar Structure and Temporomandibular Articular Disc Injury in Adolescents

Abstract Objective: To evaluate the correlation between temporomandibular joint (TMJ) disc injury and condylar structure in adolescents. Methods: A total of 94 temporomandibular joints were studied in 47 patients who underwent MRI examination of TMJ in our hospital from April 2019 to December 2020, including 32 in the non-displacement group(ND), 22 in the reducible displacement group(RD), and 40 in the non-reducible displacement group(NRD). For them, a 3.0T MRI scan was performed with conventional sequences, as well as 3D-CUBE T2 and T2-mapping sequences. Maximum left-right and antero-posterior diameters of condyles were measured by multi-plane recombination (MPR) on 3D-CUBE T2 sequence images, whose product and quotient were also calculated. Qualitative and quantitative indicators were included for evaluation of articular disc injury. By reading the films of conventional sequences comprehensively, articular disc displacement was qualitatively classified into non-displacement, reducible displacement and non-reducible displacement. The T2 value of the articular disc was measured on the T2-mapping sequence as a quantitative indicator. Four parameters of condylar structure and 2 indicators of articular disc injury were analyzed using descriptive statistics, one-way analysis of variance and Pearson correlation analysis. Results: There were statistically significant differences in three structural parameters of the condyle (left-right and antero-posterior diameters and their products) among the non-displacement, reducible and non-reducible displacement groups (P<0.001), and the corresponding mean values were ranked in descending order: values in the non-displacement group > values in the reducible group > values in the non-reducible group. The left-right and antero-posterior diameters and their products were slightly positively correlated with the T2 values of the articular disc (r=0.262, r=0.317, r=0.386, P<0.05). Conclusion: The left-right diameter, antero-posterior diameter and product of the condyle decreased with aggravation of TMJ disc injury, they can be used as the indirect imaging features of temporomandibular disorder.