Dental and skeletal changes following sagittal split osteotomy for correction of mandibular prognathism

Skeletal and dental changes were examined in 15 patients presenting with a Class III malocclusion treated by a sagittal split osteotomy. All patients received orthodontic treatment with Straightwire appliances both prior to and following surgery. These appliances were also used for fixation. The lower incisors were proclined by 8.4 degrees before surgery with little change in upper incisor inclination. With surgery, there was a mean reduction of 4.3 degrees in the angle SNB. Following surgery, the relapse in mandibular position was minimal and was not related to the dental changes during this period. Changes in the vertical skeletal parameters were generally small. The individual cases exhibited a wide variation in the changes.