목적: To evaluate and compare three-dimension (3D) of the upper airway morphology, palatal dimension and maxillary width by using cone beam computed tomography (CBCT) in children with unilateral cleft lip and palate (UCLP) with and without obstructive sleep apnea (OSA) 방법:Prospective study in children with UCLP used cone beam computed tomography (CBCT) and polysomnography (PSG) studies. All CBCT images were reoriented using Dolphin 3D imaging software (version 11.7 premium) which measured the volume and the most constricted cross-sectional area in nasopharynx, oropharynx and hypopharynx. 3D palatal morphology was constructed with Mimics software. Digital measurements of linear and volumetric dimensions of palatal structure and maxillary width were performed. Differences in these measurements between the OSA and non OSA group were compared. 결과:The means of oropharyngeal, hypopharyngeal, and total volume in UCLP children were lower than those in non-cleft children. The most constricted axial area of the oropharyngeal airway in UCLP children was narrower than that in non-cleft children. Furthermore, in the OSA group palatal surface area, volume and height were significantly lower than in non OSA group. 결론:The volume and most constricted axial area of the upper pharyngeal airway in UCLP children were significantly smaller than those in non- cleft children. UCLP children with OSA had significant reduced palatal volume, surface area and height compared to the non OSA group.