Morphological changes in the upper airway following mandibular distraction osteogenesis in craniofacial microsomia patients with obstructive sleep apnoea.

This retrospective study aimed to determine the morphology of the upper airway of craniofacial microsomia (CFM) patients with obstructive sleep apnoea (OSA) both pre- and post-mandibular distraction osteogenesis (MDO), and to compare differences in airway changes according to the therapeutic efficacy for OSA. The CFM patients with OSA were divided into 'effective' and 'ineffective' groups based on the therapeutic efficacy of MDO for OSA. Pre- and post-MDO craniofacial CT data were imported into Mimics software for three-dimensional upper airway reconstruction, which was further segmented into the nasal cavity, nasopharynx, velopharynx, glossopharynx, and laryngopharynx. The volume, surface area, length, mean cross-sectional area, and minimum cross-sectional area (minCSA) were measured. Intra-group comparisons of pre- and post-MDO data were performed, and the percentage changes (pre- to post-MDO) were compared between the two groups. Twenty-five patients were included, 10 in the ineffective group and 15 in the effective group. In both groups, the minCSA (P = 0.002, P = 0.015) and volumes of the nasopharynx (P = 0.018, P = 0.018), velopharynx (P = 0.006, P = 0.012), and glossopharynx (P = 0.007, P = 0.004) increased significantly after MDO. There were no statistically significant differences in the percentage changes in upper airway measurements between the two groups (all P > 0.05). The upper airway of CFM patients with OSA increased post-MDO, but the difference in therapeutic efficacy of MDO for OSA was not solely due to differences in the changes in morphology of the upper airway.