Surgical and Conservative Treatment of Temporomandibular Joint Anterior Disc Displacement in Adults: A Cohort Study on Condylar Remodelling

BACKGROUND: Surgical and conservative treatments are primary options for anterior disc displacement without reduction (ADDWoR) of the temporomandibular joint. However, their long-term effects on condylar remodelling remain unclear. This study aimed to investigate and compare the long-term effects of both strategies on condylar remodelling. METHODS: After being informed of both treatment options, patients with ADDWoR independently selected either disc repositioning surgery or conservative treatment with intra-articular injections combined with stabilization splints. CBCT scans were obtained at baseline and 12 months post-treatment. Quantitative assessments included condylar height, length and width, anterior joint space and condylar degenerative scores, with condylar height as the primary outcome. Postoperative condylar changes were evaluated qualitatively. RESULTS: The surgical group included 91 patients (129 joints) and the conservative group 102 patients (139 joints). At 12 months, mean condylar height increased by 0.24 mm in the surgical group but decreased by 0.89 mm in the conservative group. Most condyles were classified as "stable" or "improved" in the qualitative evaluation of condylar bone changes (surgical group: 86.0%; conservative group: 71.9%). Notably, among young adult patients with pre-existing degenerative condylar changes, 61.9% of condyles showed improvement after surgery compared to 28.1% in the conservative group. Surgical intervention also led to a greater reduction in condylar degenerative scores in this subgroup. CONCLUSION: Both surgical and conservative treatments promoted favourable condylar remodelling in patients with ADDWoR. Surgery was associated with preservation or a slight increase in condylar height, whereas conservative treatment resulted in a slight height reduction. Furthermore, among young adult patients with pre-existing condylar degeneration, surgical intervention demonstrated greater improvement in degenerative changes. TRIAL REGISTRATION: ClinicalTrials.gov: ISRCTN99353996.