This study aimed to characterize the three-dimensional (3D) upper airway morphology in children with bilateral craniofacial microsomia (BCFM) and to evaluate its association with obstructive sleep apnea (OSA).

A retrospective cross-sectional study was conducted involving 9 BCFM children and 10 age- and gender-matched controls. All participants underwent craniofacial CT imaging and polysomnography. The upper airway was segmented into four anatomical regions (nasopharynx, velopharynx, glossopharynx, and laryngopharynx) using a standardized 3D coordinate system. Morphometric parameters including volume, vertical height, minimum cross-sectional area (CSA), and maximum diameters were measured. Statistical analyses were performed to compare groups and assess correlations with obstructive apnea-hypopnea index (OAHI) and oxygen saturation (SpO₂).

Significant reductions in nearly all airway dimensions were observed in the BCFM group compared to controls ( P < 0.05), with large effect sizes (Cohen’s d > 0.8 or |r| > 0.5). Total airway volume was markedly smaller in BCFM patients (median 10,569.86 mm³ vs. 22,957.68 mm³, P < 0.001). The velopharynx and glossopharynx showed the most pronounced decreases. Strong negative correlations were identified between OAHI and both velopharyngeal volume (r = −0.717, P = 0.030) and total airway volume (r = −0.800, P = 0.014). SpO₂ was positively correlated with laryngopharyngeal volume (r = 0.778, P = 0.017).

Children with BCFM exhibit significant 3D morphological alterations in the upper airway, characterized by reduced volumes and restricted dimensions. This preliminary study suggests a strong association between airway morphological alterations and OSA severity in children with BCFM and provides a foundation for tailored therapeutic interventions.