Impact on the pharyngeal airway space of different orthognathic procedures for the prognathic mandible

The study objective was to evaluate, through a meta-analysis, the impact on the pharyngeal airway space (PAS) of different orthognathic surgeries for the treatment of the prognathic mandible. An electronic search of three databases and hand searches were carried out up to December 2014. The inclusion criteria were clinical human studies, including randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies, with the aim of comparing bilateral sagittal split osteotomy (BSSO) to intraoral vertical ramus osteotomy (IVRO), or one-jaw to two-jaw surgery for the treatment of the prognathic mandible. The PAS changes (anterior posterior dimensions and cross-sectional area) at the level of the nasopharynx, oropharynx, and hypopharynx were analyzed. A statistically significant difference was found between BSSO and IVRO groups and one-jaw surgery and two-jaw surgery with regard to PAS changes after the treatment of mandibular prognathism. The results of this meta-analysis indicate that BSSO presents less change in the PAS after mandibular setback surgery compared to IVRO. Furthermore, the results of this study suggest that bimaxillary surgery is superior to mandibular setback surgery alone for the correction of the prognathic mandible, particularly in patients with factors predisposing them to the development of breathing problems.