Assessment of nasal respiration and three-dimensional airway volume changes in orthognathic surgery patients

Objectives: The aim of this study was to evaluate the effect of maxillary movements in orthognathic surgery on nasal airway volume change and its correlation with airflow and resistance. Materials and methods: This study included 25 patients (8 male, 17 female) with Class II (6 patients) or Class III (19 patients) malocclusion. All patients underwent Le Fort I and bilateral sagittal split ramus osteotomy. Nasal airflow and resistance were measured by using rhinomanometry and acoustic rhinometry pre and six months post-operatively. Nasal volume was measured using computed tomography before surgery and six months after surgery. Results: Nasal volume increased in 10 out of 11 patients with CCW (counterclockwise) rotation and decreased in 1 patient while, nasal volume increased in 5 patients with CW (clockwise) rotation and decreased in 9 patients. Superior nasal airway volume increased significantly, while the effects on nasal flow and resistance were not significant. Additionally, no significant correlation was found between airway volume changes and variations in airflow and resistance. Conclusion: CCW rotation in orthognathic surgery patients significantly increased superior nasal airway volume but did not improve nasal airway flow and resistance.