Assessment of the pharyngeal airway space after mandibular setback surgery

Purpose: This retrospective study evaluated the change in pharyngeal airway space associated with surgical mandibular setback. Patients and Methods: Lateral cephalograms of 14 adult patients taken preoperatively, immediately postoperatively, and at long-term follow-up were traced, and the width of the pharyngeal airway space and the pharyngeal airway space area were calculated and compared. Results: At long-term follow-up, the mean amount of mandibular setback was 9.7 mm. The mean reduction in the distance from the tongue base to the posterior pharyngeal wall was 4.77 mm (28% decrease). The mean reduction in pharyngeal airway space area was 1.52 cm², which corresponded to a 12.8% reduction. There was a strong correlation between the amount of mandibular setback and the decrease in pharyngeal airway space area. Conclusion: Mandibular setback surgery causes a long-term decrease in pharyngeal airway space area. In patients who have other risk factors, for example, overweight, short necks, or large tongues, a mandibular setback procedure could possibly predispose to the development of sleep apnea syndrome.