This study aimed to assess nasal airflow, nasal resistance, and the cross-sectional area of the nasal cavity in patients who have had maxillary superior repositioning (MSR). This is a cross-sectional study, and nasal airflow, nasal resistance, and the cross-sectional area of the nasal cavity were evaluated by rhinometry and acoustic rhinometry techniques in patients who had had MSR. Thirty-two patients were studied, and the mean (SD) MSR was 5.03 (1.61) (range 3-8) mm. There was a significant correlation between the mean MSR and the mean change in nasal airflow and nasal resistance (p=0.001 and p=0.005, respectively). There was also a correlation between MSR and the change in the cross-sectional area of the inferior concha (p=0.001), but there was no correlation between the mean MSR and the change in cross-sectional area of the isthmus (p=0.07). Nasal airflow increases when the mean MSR is less than 6.5mm, and when maxillary impaction is 6.5mm or more, nasal airflow decreases. It seems, therefore, that MSR of less than 6.5mm was associated with an improvement in nasal airflow. When maxillary impaction was more than 6.5mm, nasal airflow and the cross-sectional area of the nasal cavity decreased, and nasal resistance increased.