Purpose <p>Bracing has long been the mainstay of conservative management for adolescent idiopathic scoliosis (AIS) yet there is little data comparing treatment outcomes among different brace types. The purpose of this study is to compare curve progression and need for surgery between patients treated with Rigo Cheneau-style orthoses (RCSO) that focus on three-dimensional correction and traditional thoracolumbar-sacral orthoses (TLSO).</p> Methods <p>Patients who began treatment at a single institution with an initial major coronal curve between 20° and 45° and no previous scoliosis treatment were included. Study endpoints were skeletal maturity or definitive fusion surgery. The outcome measures were percent curve correction in-brace, coronal curve progression at study endpoint, major coronal curve progression &gt; 5°, major coronal curve progression &gt; 10°, and progression to surgery.</p> Results <p>89 patients (47 RCSO and 42 TLSO) were included. Traditional TLSO patients had lower mean initial major curve compared to the RCSO cohort (30° vs. 33°, <i>p</i> = 0.021). TLSO patients had lower in-brace curve correction percent (22% vs. 48%, <i>p</i> &lt; 0.001). Fifty-five percent of TLSO patients experienced curve progression of more than 5° compared to 30% of RCSO patients (<i>p</i> = 0.017). Forty-three percent of patients treated with TLSO experienced curve progression of more than 10° compared to only 13% of patients treated with RCSO (<i>p</i> = 0.001). By univariable analysis, there were no differences between TLSO and RCSO in risk of surgery recommended or performed (31% vs 30%, <i>p</i> = 0.905). However, the baseline predicted risk of progression ≥ 45° at initiation of bracing was lower in the TLSO cohort (49.1% vs. 61.5%, <i>p</i> = 0.079).</p> Conclusions <p>Patients treated with RCSO have a higher in-brace curve correction and lower odds of curve progression compared to patients treated with TLSO.</p>