Facial features and hyoid bone position in preschool children with obstructive sleep apnea syndrome.

The aim of the study was to evaluate facial features and hyoid bone position in children with obstructive sleep apnea syndrome (OSAS) by cephalometric radiography. A prospective cross-sectional study was conducted in a tertiary referral hospital. Twenty-nine children in the 3-6 year age bracket were evaluated: 14 children with OSAS and 15 nasal-breathing children. All children underwent otorhinolaryngologic examination, and those with OSAS also underwent in-laboratory polysomnography for diagnostic confirmation. The children were then submitted to orthodontic evaluation and cephalometry. Lateral cephalometric radiographs from children with OSAS were compared to those of nasal-breathing children. We found no differences between the two groups regarding the linear and angular measurements of the face. However, the children with OSAS presented, already at the preschool age, with an inferiorly positioned hyoid bone, thus increasing the pharyngeal area. In children with OSAS, the hyoid bone appears to be in a significantly inferior position at an early age. Our findings provide evidence that there is a relationship between the position of the hyoid bone and OSAS in children, which could contribute to the persistence of OSAS into adulthood.