Efficacy of a digitally designed anatomical repositioning splint for adolescent temporomandibular joint anterior disc displacement with reduction: a randomized controlled trial

Background: Anterior disc displacement with reduction (ADDwR) is a common temporomandibular joint disorder in adolescents. Conventional anterior repositioning splints (ARS) often lack anatomical adaptation, which may limit their therapeutic precision and patient comfort. This study aimed to compare the efficacy of a digitally designed anatomical repositioning splint (D-ARS) with that of a conventional ARS in adolescent ADDwR patients. Methods: In this randomized controlled trial, 82 adolescents (aged 12–16 years) with ADDwR were randomly allocated to receive either a D-ARS (n = 41) or an ARS (n = 41). At the 6‑month follow‑up, clinical outcomes were evaluated through three modalities: disc recapture was assessed by magnetic resonance imaging (MRI), condylar volume changes were measured using cone‑beam computed tomography (CBCT), and patient‑reported wearing comfort was quantified with the Oral Impacts on Daily Performance (OIDP) questionnaire. Statistical analyses included chi-square tests, t-tests, and non-parametric tests as appropriate. Results: The D-ARS group achieved a significantly higher disc recapture rate than the ARS group (94.44% vs. 79.63%, p = 0.022). Both groups showed significant increases in condylar volume [D-ARS: +202.17 mm³ (95% CI: 177.72–226.63), ARS: +208.9 mm³ (95% CI: 178.8–241.25), both p < 0.001], with no intergroup difference (p = 0.5615). Patient-reported comfort was superior in the D-ARS group, with lower OIDP scores (14.43% vs. 35.63%, p < 0.001). Conclusions: At the 6-month follow-up, the D-ARS group exhibited significantly better disc recapture success and patient-reported wearing comfort than the ARS group, while no significant difference was observed between the two groups in terms of condylar growth promotion. Trial registration: Chinese Clinical Trial Registry (ChiCTR2400080947, registered on February 19, 2024). Available from: http://www.chictr.org.cn/.