The objective was to determine the primary correction of the Cobb angles of 147 idiopathic scoliosis subjects wearing the Rigo System Chêneau (RSC) brace. The RSC brace is a scoliosis brace that incorporates expansion and pressure areas to treat all aspects of the 3D scoliotic deformity not only in the frontal plane but also in the sagittal and transverse planes. RSC brace uses specific clinical and radiological classifications to define the most effective principles of correction. The experimental hypothesis predicted that those subjects who are treated with the RSC brace would report a significant primary correction of the major, minor, thoracic, and lumbar Cobb angles for both the main and Society of Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT) restrictive criteria groups. The primary correction of main group was 43°, 42°, 48°, and 37° for thoracic, lumbar, major, and minor curve, respectively. The primary correction of SOSORT group was 54°, 59°, 61°, and 52° for thoracic, lumbar, major, and minor curve, respectively. The present experiment focused on the radiographic measurements of idiopathic scoliosis subjects before treatment and the primary correction with the RSC brace. The results are based on a sample size of 147 subjects in the main group and 25 subjects in the SOSORT (restrictive criteria) group. As a result, the RSC brace system had significant primary corrections in both the main and SOSORT groups. Because the initial in-brace radiographs presented with favorable results, it is predicted that the RSC brace prevents curve progression at the end of the treatment.