Upper airways after mandibular advancement orthognathic surgery: A 4-year follow-up.

INTRODUCTION: The purpose of this study was to assess the stability of changes in the upper airways 4 years after orthognathic surgery in patients with skeletal Class II malocclusion. METHODS: A retrospective clinical study was conducted including 33 cone-beam computed tomography images from 11 patients (average age of 35.91 years) followed up longitudinally for 4 years. The airways were measured with the help of the Dolphin Imaging software (Dolphin Imaging and Management Systems, Chatsworth, Calif) at 3 points: T1 (preoperative), T2 (6 months after surgery), and T3 (4 years after surgery). The parameters assessed were surface area (SA), minimum axial area, and volume (VOL) of the pharyngeal airway space. The times were compared using analysis of variance and Tukey's test. Pearson's analysis was performed to assess the correlation with surgical changes and age (P <0.05). RESULTS: Four years after operating on the airway spaces, the means of SA and VOL were significantly higher than those observed before the surgery (P <0.05). The means at 6 months were intermediate, with no significant difference before the surgery and 4 years after it (P >0.05). There was no significant correlation of the changes in SA, VOL, and minimum axial area with the amount of mandibular advancement, counterclockwise rotation of the occlusal plane, and age of the patient (P >0.05). CONCLUSIONS: Four years after mandibular advancement surgery in patients with skeletal Class II malocclusion, the increases in the airways remained stable.