[Evaluation of histological changes of retrodisc attached tissue in patients with temporomandibular disorders by texture analysis: a pilot study].

Objective: To evaluate the histological changes of the retrodiscal tissue in the patients with temporomandibular disorders (TMD). Methods: Thirty-three TMD patients were performed with temporomandibular joint (TMJ) MRI examinations from April 2018 to April 2020 in TMD clinic, Hainan Hospital of General Hospital of Chinese PLA. The patients groups were classified according to the disc position as follows: normal position (NP) (29 TMJ), disk displacement with reduction (DDwR) (14 TMJ) and disk displacement without reduction (DDwoR) (23 TMJ). The gray-level co-occurrence matrix (GLCM) analysis was applied with the retrodiscal tissue on the open oblique sagittal proton weighted images. The texture parameters included as follows: angular second moment (ASM), contrast, correlation, inverse difference moment (IDM) and entropy. The statistical methods mainly included Kruskal-Wallis H test, one-way analysis of variance and receiver operating characteristic curve (ROC), to analyze the texture characteristic parameters of the retrodiscal tissue are statistically significant. Results: There was no significant difference of the retrodiscal tissue's ASM, contrast, correlation and IDM among 3 groups (P>0.05). The entropy in NP group (3.98+/-0.44) and DDwR group (4.20+/-0.52) presented significant higher than that in DDwoR group (3.70+/-0.38) (P<0.05). ROC analysis for the entropy demonstrated that the area under the curve was 0.70 when differentiating NP and DDwR (cut-off value 0.38, sensitivity 82.61%, specificity 55.17%), and was 0.79 when differentiating DDwR and DDwoR (cut-off value 0.47, sensitivity 82.61%, specificity 64.29%). Conclusions: Texture entropy could be primarily used to evaluate the histological and pathological changes of the retrodiscal tissue in the TMD patients.