STUDY DESIGN/SETTING: This retrospective study analyzed bracing outcomes in patients with adolescent idiopathic scoliosis (AIS), focusing on curve pattern changes and brace efficacy. OBJECTIVE: To analyze the effectiveness of the Chêneau brace across different curve patterns and to evaluate the tendencies in curve evolution during treatment. BACKGROUND: AIS presents diverse curve patterns, each responding differently to bracing. Understanding these variations is crucial for optimizing treatment strategies. PATIENTS AND METHODS: The study included 177 patients with AIS treated with Chêneau orthoses, categorized based on curve patterns as per the main curve and modified Lenke (mLenke) classifications. We compared patients according to curve patterns and assessed changes in curve magnitude and pattern before and after treatment. RESULTS: Over an average follow-up of 28.1 ± 10.7 months, the primary curve magnitude decreased from 28.8 ± 6.6° to 25.9 ± 10.5°. Significant reductions were observed in mLenke V and VI patients ( P <
0.05). Patients with main lumbar curves showed better initial in-brace correction and curve control compared with those with main thoracic curves ( P <
0.05). In single-curve patterns, binary logistic regression indicated that mLenke V patients demonstrated higher rates of curve control compared with mLenke I patients ( P <
0.05). No significant differences were found in double-curve patterns between mLenke III and VI ( P >
0.05). At the final follow-up, thoracolumbar/lumbar curves improved significantly in mLenke III and VI patients ( P <
0.05), whereas thoracic curves did not ( P >
0.05). Furthermore, at the last follow-up, the proportions of mLenke I, II, and IV increased, whereas mLenke III, V, and VI decreased. CONCLUSIONS: Bracing outcomes were more favorable in patients with main lumbar curves than those with main thoracic curves. However, no significant differences were found in patients with double-curve patterns. Thoracic curves exhibited a higher progression risk compared with thoracolumbar/lumbar curves within the same curve pattern. During bracing, a tendency for primary curves to shift proximally was noted. LEVEL OF EVIDENCE: Level III.