40 patients with adolescent idiopathic scoliosis were randomized to have a computer-aided design and manufactured thoraco-lumbo-sacral orthosis with or without the addition of finite element simulation during the design process. Patients underwent radiographic evaluation during brace wearing to assess correction in thoracic and lumbar Cobb angle, as well as thoracic kyphosis and lumbar lordosis angles. Results demonstrated a significantly greater reduction in thoracic Cobb angle in the CAD/CAM+FEM group compared to the CAD/CAM only group. All other radiographic findings did not significantly differ between groups.