Correlation between craniofacial changes and respiratory improvement after nasomaxillary skeletal expansion in pediatric obstructive sleep apnea patients.

Purpose: The aim of this study was to investigate the correlation between the changes in respiratory function and dimensions of the nasomaxillary complex (NMC) and upper airway (UA) compartments after nasomaxillary skeletal expansion (NMSE) treatment for pediatric patients with obstructive sleep apnea (OSA).

Methods: Nonobese OSA patients (mean age, 13.6 ± 2.9 years; mean body mass index, 18.1 ± 3.0 kg/m); mean apnea-hypopnea index (AHI, 7.0 ± 5.4 events/h) presenting with transverse nasomaxillary constriction were evaluated before and after NMSE using cone-beam computed tomography (CBCT), home sleep test, and modified pediatric sleep questionnaire (m-PSQ). Paired t tests were performed to examine the treatment-related changes in all the parameters, and a multiple regression analysis adjusted for age and sagittal and vertical skeletal patterns was conducted to determine the dimensional parameters to affect the functional improvement.

Results: Among 26 patients, NMSE treatment significantly increased NMC dimensions at all tested levels and all UA compartments in CBCT, except glossopharyngeal airway. Concurrently, AHI, oxygen desaturation index, the lowest oxygen saturation (LSaO), flow limitation (FL), snoring, and m-PSQ were significantly improved. AHI reduction was correlated with UA enlargement with no correlation with NMC expansion, whereas FL reduction was affected by NMC expansion. The minimal cross-sectional area was the most predictive of functional improvement, presenting correlations with AHI, LSaO, and m-PSQ.

Conclusion: NMSE can be a good treatment for pediatric OSA patients when applied to enhance the nasal and pharyngeal airway patencies beyond the NMC, ultimately to improve pharyngeal collapsibility as well as nasal airflow.