The Class III skeletal open bites of six randomly selected patients were corrected by extraoral subcondylar ramus osteotomies. Cephalometric radiographs were taken from immediately prior to surgery to 30 months later. Relapse - change in jaw position - was evaluated in a Cartesian coordinate system to quantify both horizontal and vertical skeletal and dental changes. The proximal segment displacement at surgery and its relationship to subsequent relapses was analyzed and results were reported for each patient. Also discussed are disparities between mean value data and individual relapse tendencies; the importance of early relapse evaluation; and anatomic considerations in relapse. Recommendations in surgical techniques are made to improve the predictability and stability of results.