We investigated risk factors for obstructive sleep apnea hypopnea syndrome (OSAHS) induced by orthognathic surgery for the treatment of malocclusion, and analyzed preoperative and postoperative findings. In Part 1, we reported on the relationship between polysomnographic findings and direction of jaw movement before and after orthognathic surgery. In this study (Part 2), we investigated the relationship between the pharyngeal airway space on lateral cephalometric radiographs and polysomnographic findings in the cases studied in Part 1 As a result, the pharyngeal airway space was influenced more by mandibular movement than by maxillary movement. Further, there was no correlation between changes in the pharyngeal airway space and polysomnographic findings. Therefore, to determine the relationship between orthognathic surgery and sleep-disordered breathing, we consider it important to evaluate functional change rather than morphological change.
