Three-dimensional assessment of the nasopharyngeal airway in Down syndrome during the mixed dentition period: a case-control study

Down syndrome (DS) is the most common chromosomal disorder caused by the genetic trait of trisomy 21. Children with DS have been reported to have a higher prevalence of obstructive sleep apnea (OSA). It is important to undertake nasopharyngeal airway assessment in children with DS during the growing stage to understand the factors causing OSA. However, no studies to date have included three-dimensional assessment of the nasopharyngeal airway in children with DS. The aim of the present study was to evaluate the nasopharyngeal airway volume of children with DS and compare the results with those of control subjects well-matched for sex and age. We enrolled 15 DS and 15 control subjects. The nasopharyngeal airway volume and the cross-sectional morphology were measured with cone-beam computed tomography taken for orthodontic treatment. Nasal airway and superior airway volumes of DS subjects were significantly smaller than those of the control subjects. Our results indicate that the nasopharyngeal airway volume differs between children with and without DS, and these differences could be a potential risk factor in the occurrence of OSA in children with DS during the growing stage.