Morphological factors influencing the progression of temporomandibular joint anterior disc displacement with reduction to without reduction after contralateral joint arthroscopic discopexy: a retrospective study

The aim of this retrospective cohort study was to identify morphological risk factors associated with the progression of temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR) to without reduction (ADDwoR) in the contralateral joint following arthroscopic discopexy. Among 80 patients, 26 divided into a ‘progression’ group versus 54 without progression based on the disc position in the contralateral joint at postoperative follow-up. Patient characteristics and the disc length, disc folding angle, anterior distance of the disc relative to the condyle, and angle between the disc and condyle were analysed. Univariate analysis revealed that longer anterior distance and greater angle between the disc and condyle increased ADDwoR risk(both P < 0.001), while a longer disc length (P < 0.001) and a greater disc folding angle (P = 0.034) reduced progression likelihood. Multivariable logistic regression and receiver operating characteristic curves confirmed disc length and anterior distance to be significantly associated with progression to ADDwoR. In conclusion, following unilateral arthroscopic discopexy, patients with contralateral ADDwR are at risk of progression to ADDwoR, with disc length and anterior distance relative to the condyle being key morphological risk factors.