Does clockwise rotation of the maxillomandibular complex using the surgery-first approach to correct mandibular...

In mandibular prognathism, correction by clockwise rotation (CWR) of the maxillomandibular complex (MMC) can improve the facial appearance and allow greater mandibular setback. However, cohort studies comparing changes in the pharyngeal airway between CWR and control groups are lacking. This prospective cohort study included 70 adults who underwent the correction of skeletal Class III malocclusion with or without CWR. Airway volume changes were compared between preoperative (T0), 1 month postoperative (T1), and 1 year postoperative (T2). The patients were divided into CWR and control groups according to the change in maxillary occlusal plane from T0 to T1 (CWR group >4°; control group ≤4°). Covariates were sex, age, genioplasty, and airway volumes at T0, T1, and T2. The primary outcome variable was whether there was a volume increase or decrease between T1 and T2. The total pharyngeal, nasopharyngeal, oropharyngeal, and hypopharyngeal volumes decreased between T0 and T1 and then increased between T1 and T2 in both groups; there was no significant difference in the changes in volume between the groups. In the volume-increase group, the changes in airway volume (T0-T1 and T1-T2) were similar to those of the control group. Overall, CWR of the MMC did not significantly affect the pharyngeal airway volume changes T0-T1 or T1-T2, as compared with the control group.