Impact of different surgery modalities to correct class III jaw deformities on the pharyngeal airway space

The objective of the study was to compare the outcome of different modalities of orthognathic surgery to correct class III jaw deformities concerning the pharyngeal airway space, especially in patients with other predisposing factors for the development of obstructive sleep apnea.

Lateral cephalograms of 30 Japanese patients (12 males and 18 females, 24.4 [SD, 6.8] years), who underwent surgical-orthodontic treatment for class III jaw deformities, were obtained. Patients were divided into 3 groups: Group A included patients who underwent bilateral sagittal split ramus osteotomy; group B patients underwent bimaxillary surgery, and group C patients underwent intraoral vertical ramus osteotomy. Lateral cephalograms were assessed before surgery and around 3 months and 1 year after surgery. The paired t-test was used to compare the groups, and P < 0.05 was considered significant.

In groups A and C who underwent sagittal split ramus osteotomy and intraoral vertical ramus osteotomy, respectively, the pharyngeal airway was constricted significantly at the 3 levels of the pharyngeal airway space on short- and long-term follow-up, whereas in group B, who underwent bimaxillary surgery, no significant changes were noted on long-term follow-up.

Bimaxillary surgery rather than only mandibular setback surgery is preferable to correct class III jaw deformity to prevent narrowing of the pharyngeal airway, which might be a predisposing factor in the development of obstructive sleep apnea syndrome.