What Is the Impact of Distraction Osteogenesis on the Upper Airway of Hemifacial Microsomia Patient With OSA: a Case Report

Abstract Background: Current researches about hemifacial microsomia (HFM) patients after distraction osteogenesis (DO) most emphasize the morphologic changes. This case report shows the outcome of DO on the upper airway of a HFM patient with obstructive sleep apnea (OSA) based on the use of computational fluid dynamics (CFD).Case presentation: A boy of 11-year-old was diagnosed as HFM with OSA, and underwent unilateral DO. Polysomnography and CT scans were performed before and six months after treatment. After DO, lowest blood oxygen saturation increased from 81% to 95% and apnea and hypopnea index decreased from 6.4 events/hour to 1.2 events/hour. The oropharynx and nasopharynx were obviously expanded. We observed apparently increased average pressure, decreased average velocity and pressure drop in all cross-sections, and largely decreased airflow resistance and maximum velocity entirely in the airway.Conclusions: The results suggest that DO might be effective for the treament of OSA by expanding the upper airway and reducing the resistance of inspiration.