Study DesignRetrospective Cohort Study.ObjectivesTo assess the efficacy and compliance of early night-time bracing in adolescent idiopathic scoliosis with curve magnitudes between the recently proposed early-intervention threshold (15°) and the traditional treatment threshold (25°) recommended by the Scoliosis Research Society (SRS).MethodsThis dual-center retrospective study included 153 AIS patients (Risser 0-3, Cobb angle 15°-25°) treated with the Dresdner Night-Time Brace (DNTB) between 2002 and 2021. Patient demographics, patient compliance, and radiographic outcomes were analyzed. Treatment success was defined by curve stabilization or regression. Statistical analysis was performed with significance set at P < 0.05.ResultsThe DNTB achieved a mean in-brace correction of 60.9%, moderately correlated with the initial Cobb angle. Compliance was high: 72.6% of patients were compliant, 15.0% partially compliant, and 12.4% non-compliant. The in-brace correction angle was associated with compliance but not with age, sex, or initial curve magnitude. Compliance significantly influenced outcomes (P < 0.05). Overall curve progression was 12.5%, but only 2.7% in compliant patients, compared to 30.4% and 47.4% in partially and non-compliant groups, respectively. Surgery was required in 10.5% of non-compliant cases.ConclusionsEarly intervention with the DNTB is an effective and well-tolerated treatment for mild AIS (15°-25°), with treatment success highly dependent on patient compliance. These findings underscore the importance of timely bracing and sustained compliance.