Evaluation of Nasal Function and Upper Airway Morphology After Bi-Maxillary Surgery Using Rhinomanometry and Computed Tomography.

Purpose This study was performed to evaluate changes in nasal airflow, nasal airway resistance, nasal cross-sectional area, pharyngeal horizontal area, nasopharyngeal and oropharyngeal volume following Le Fort I osteotomy (L1) impaction with sagittal split ramus osteotomy (SSRO) in classes II and III. Materials and methods The subjects consisted of 35 patients (6 males and 29 females, 70 sides) 17 of which were diagnosed as class II and 18 as class III who underwent L1 and SSRO. Nasal airflow and resistance were measured using the rhinomanometry system (GM NR-6 EXECUTIVE) before and at 1 and 6 months after surgery. Nasal, cross-sectional area, and volume were measured using a 3-dimensional computed tomography respectively, before and 1-year after surgery. Results Although a significant decrease was found in nasal volume after surgery (P = 0.0042), there was no difference between before and after surgery in the nasal airway resistance in class II.A significant decrease in nasal volume was found after surgery (P = 0.0005) and there were no postoperative changes in both nasal airflow and resistance in class III. Conclusion The study suggested that L1 impaction with SSRO did not worsen nasal function such as nasal airflow and nasal airway resistance, although nasal volume significantly decreased in both groups.