A prospective cohort study on the efficacy of conservative and surgical treatments for patients with ADDwoR of the temporomandibular joint

Background: The treatment options for anterior disc displacement without reduction (ADDwoR) of the temporomandibular joint (TMJ) are conservative and surgical treatments; however, current therapeutic strategies for ADDwoR remain highly heterogeneous. This study aimed to evaluate the effectiveness of these two treatment options in symptom alleviation and orofacial functional restoration. Methods: The age of the patients was 18 years or older, and they underwent treatment for ADDwoR of the TMJ from December 2022 to February 2024, with patients providing 12-month follow-up data on pain, mouth-opening capacity, and chewing efficiency. The difference in the change in joint pain levels between the two methods was assessed from the baseline to the 12-month follow-up period. Mouth-opening capacity and chewing efficiency were assessed by pain-free maximum mouth opening and the TMJ chewing function self-test. Results: A total of 218 participants [mean (SD) age = 31.9 (12.9) years; 195 (89%) women] were included in this study, and the conservative treatment group and surgical treatment group included 123 individuals [mean (SD) age = 32.9 (12.7) years; 113 (92%) women] and 95 individuals [mean (SD) age = 30.6 (13.1) years; 82 (86%) women], respectively. Both the conservative treatments [mean change =− 2.45 (95% CI = −3.031 to −1.864) points] and surgical treatments [mean change =− 2.24 (95% CI −2.867 to −1.603) points] resulted in a clinically important pain reduction at 12 months. However, there was no significant difference in the effects of conservative and surgical treatments on pain reduction ( P = 0.5737). The results of the secondary outcomes were mostly in line with those of the primary outcomes. Interestingly, among middle-aged and elderly patients with limited mouth opening, surgical treatments demonstrated a superior restoration of mouth-opening capacity compared to conservative treatments ( P = 0.0049). Conclusions: In this cohort study of individuals with ADDwoR of the TMJ, both conservative and surgical treatments significantly improved clinically relevant pain, mouth-opening capacity and chewing efficiency in patients. And surgical intervention demonstrated superior efficacy in enhancing mouth opening among middle-aged and elderly patient.