Condylar Bone Remodeling After TMJ Disc Repositioning Using Sutureless Screws Versus Suture Anchors for Anterior Disc Displacement Without Reduction: A Prospective Cohort Study.

objectiveTemporomandibular joint (TMJ) disc repositioning is an effective treatment for anterior disc displacement without reduction (ADDWoR). This study aimed to evaluate the 12-month bone remodeling outcomes following sutureless repositioning screw fixation and to explore whether there is a significant difference in condylar bone remodeling compared with suture anchor fixation.

methodsThis single-center prospective cohort study included patients with MRI-confirmed ADDWoR who underwent TMJ disc repositioning and fixation between June 2022 and December 2024. Patients were categorized into the sutureless repositioning screw group and the suture anchor group according to the fixation method. All patients underwent cone-beam computed tomography preoperatively (T0) and after 12 months postoperatively (T1). The primary outcome was condylar height. Secondary outcomes included condylar length and width; anterior, superior, and posterior joint spaces; glenoid fossa thickness; condylar osseous degeneration score; assessment of condylar osseous changes; and new bone formation. Continuous postoperative outcomes were analyzed using linear mixed-effects models with a patient-level random intercept, adjusting for the corresponding baseline value, age group, and fixation technique. Generalized estimating equations with patient-level clustering were used for the osseous degeneration score and binary remodeling outcomes. Age-by-technique interactions were additionally examined.

resultsA total of 69 patients (102 TMJs) were included, comprising 36 patients (55 joints) treated with sutureless repositioning screws and 33 patients (47 joints) treated with suture anchors. Both groups demonstrated favorable postoperative osseous remodeling over 12 months. In adjusted mixed-effects models, fixation technique was not independently associated with condylar height or any secondary continuous outcome. For the primary outcome, neither age group (β=0.237, 95% CI -0.068 to 0.542; P=0.128) nor fixation technique (β=0.192, 95% CI -0.104 to 0.489; P=0.204) was significantly associated with condylar height at T1. Age was independently associated with greater glenoid fossa thickness (β=0.408, 95% CI 0.137 to 0.678; P=0.003), a lower postoperative osseous degeneration score (β=-0.614, 95% CI -0.882 to -0.345; P<0.001), and higher odds of osseous improvement (OR=4.699, 95% CI 1.650 to 13.379; P=0.004). The association between age and new bone formation did not reach statistical significance (OR=3.168, 95% CI 0.958 to 10.473; P=0.059). No significant age-by-technique interaction was observed for any evaluated outcome.

conclusionSutureless repositioning screw fixation achieved reliable condylar bone remodeling outcomes at the 12-month follow-up, with no independent difference detected compared with suture anchor fixation after adjustment. Age may be associated with selected postoperative bone remodeling outcomes, and adolescent patients tended to show more favorable remodeling in some measures than adults. CLINICAL RELEVANCE: No independent difference in 12-month osseous remodeling was detected between sutureless screw and suture anchor fixation after adjustment. Age was associated with selected remodeling outcomes but should not determine fixation technique or surgical timing.