This paper from Turkey divided 28 patients into three groups: those having a maxillary advancement osteotomy, those with a maxillary advancement and impaction, and those that underwent advancement with a yaw rotation. They found that pure advancement movement of the maxilla was found to significantly increase the nasal cavity air volume. The occurrence of septal deviation and nasal airflow impairment was not statistically significant. They noted at a yaw rotation movement increased clinical rhinosinusitis symptoms. Overall, they conclude the airflow impairment following Le Fort I surgery is low. They note in general it is controversial where a Le Fort osteotomy significantly increases the rate of postoperative rhinosinusitis. They also note that maxillary impaction may increase the width of the internal nasal valve, this being the narrowest area of the nasal cavity. They suggest that it might be a useful procedure for patients with nasal flow impairment.