Volumetric Changes in the Pharyngeal Airways of Skeletal Class III Patients Following Various Orthognathic Surgeries: A Short-/Long-Term Follow-Up

Abstract

Orthognathic surgery corrects skeletal deformities affecting the pharyngeal airway. This study assessed immediate and long-term volumetric changes in the airway after surgery. In this observational study, upon orthognathic surgery, 52 class III deformity patients underwent three types of surgery: isolated mandibular setback, maxillomandibular setback, and mandibular setback with maxillary advancement. Cone-beam computed tomography was used to analyze the nasopharyngeal, oropharyngeal, and hypopharyngeal airway volumes at three time points. In isolated mandibular setback, oropharyngeal and hypopharyngeal volumes significantly decreased immediately after surgery, without long-term relapse. Maxillomandibular setback showed reduced hypopharyngeal volume in both follow-ups. Mandibular setback with maxillary advancement slightly increased nasopharyngeal volume, while oropharyngeal and hypopharyngeal volumes decreased postoperatively, increasing in the long term. Linear regression analysis revealed a prediction model for % change in pharyngeal volume using ∆B (P<0.05). Orthognathic surgery, particularly isolated mandibular setback, narrows the pharyngeal airway. Monitoring postoperative airway changes is crucial, especially for obstructive sleep apnea patients. Consideration of bimaxillary surgery with maxillary advancement may prevent the narrowing of the airway, especially in the immediate postoperative phase. Further investigation is needed to understand the dynamic long-term changes in the pharyngeal volume and also clinical outcomes, whether relapse or body compensation. A deeper understanding of these long-term effects will be critical for optimizing treatment planning, enhancing patient safety, and refining surgical strategies in orthognathic surgery.