Comparing Stability of Mandibular Setback Versus 2-Jaw Surgery in Class III Patients With Minimal Presurgical Orthodontics

Abstract

Purpose: The aim of this studywas to compare treatment time and skeletal stability between mandibular setback surgery (MS) and 2-jaw surgery (2J) with minimal presurgical orthodontics (MPO) in patients with skeletal Class III. Materials and Methods: One hundred ninety-five patients who underwent orthognathic surgery were enrolled in this retrospective cohort study. Consecutive patients were selected based on standardized inclusion criteria: Class III malocclusion with mandibular prognathism, surgery type, and presurgical orthodontics with non-extraction for less than 6 months (MPO). Lateral cephalograms were taken before surgery (T0), 1 month after surgery (T1), and at debonding (T2). To evaluate surgical changes (T0 to T1) and postsurgical changes (T1 to T2) in skeletodental tissue, linear, angular, and dental measurements were analyzed using paired t test and independent t test. Results: Thirty-one patients were allocated to the MS-MPO group (n = 16) and the 2J-MPO group (n = 15). The 2J-MPO group showed a shorter duration of postsurgical orthodontic and total surgical and orthodontic treatment than the MS-MPO group. Although the 2J-MPO group exhibited advancement and superior impaction of the maxilla from T0 to T1, posterior movement with clockwise rotation of the mandible between the 2 groups did not show a statistical difference. In addition, from T1 to T2, the MS-MPO and 2J-MPO groups presented forward and upward movement and counterclockwise rotation of the mandible, but no intergroup difference was found. Conclusions: The MS-MPO and 2J-MPO groups showed similar horizontal and vertical mandibular stability. However, the 2J-MPO group presented a shorter surgical and orthodontic treatment time than the MS-MPO group. (C) 2017 American Association of Oral and Maxillofacial Surgeons