Long-Term Stability of Pre-Orthodontic Orthognathic Bimaxillary Surgery Using Intraoral Vertical Ramus Osteotomy Versus Conventional Surgery

Purpose: The aim of the present study was to compare the long-term stability of bimaxillary surgery using an intraoral vertical ramus osteotomy (IVRO) with and without presurgical orthodontic treatment. Materials and Methods: The present retrospective study included 31 consecutive patients with skeletal Class III malocclusions who had undergone bimaxillary surgery (Le Fort I osteotomy and bilateral IVRO). Patients were divided into 2 groups based on treatment type: pre-orthodontic orthognathic surgery (POGS; n = 17) and conventional surgery with presurgical orthodontic treatment (CS; n = 14). Lateral cephalograms were obtained before surgery, 1 day after surgery, 1 month after surgery, 1 year after surgery, and 2 years after surgery to evaluate skeletal and soft tissue changes between the 2 groups. Data were analyzed using χ² tests, Mann-Whitney U tests, repeated-measures analyses of variance, and independent t tests. Results: There was no significant difference in skeletal or soft tissue measurements—with the exception of the angle between the sella-and-nasion plane and the occlusal plane (SN-OP; P <.001)—between the CS and POGS groups at 2 years after IVRO. The SN-OP had increased in the CS group but decreased in the POGS group at 2 years after surgery. Conclusions: These findings suggest that POGS and CS have similar long-term stability in patients with skeletal Class III malocclusion.