Obstructive sleep apnea (OSA): a cephalometric analysis of severe and non-severe OSA patients. Part I: Multiple comparison of cephalometric variables.

One hundred male obstructive sleep apnea (OSA) patients were classified into 2 groups, on the basis of Apnea-Hypopnea Index (AHI), as severe (AHI > or = 50) and non-severe (AHI < 50). A comprehensive cephalometric analysis of cervicocraniofacial skeletal morphology and upper airway soft tissue morphology was performed in 51 non-severe OSA patients, 49 severe OSA patients, and 36 controls with the purpose of examining the different features among these 3 groups. Sixty-eight cephalometric variables were compared among these 3 groups by 1-way analysis of variance with post hoc Bonferroni test. The results showed that both OSA groups had aberrations of cervicocraniofacial skeletal morphology and upper airway soft tissue morphology versus the controls. Severe OSA patients demonstrated increased maxillo-mandibular retrognathism, with a high mandibular plane angle resulting from increased anterior lower facial height and decreased posterior lower facial height, versus the non-severe OSA group. The craniocervical extension, forward head posture, inferiorly positioned hyoid bone, and the enlarged and elongated soft palate and upright tongue posture were more exaggerated as well. These findings imply that there should be different treatment regimens for the 2 subgroups of OSA patients to achieve treatment success. Cephalometric analysis is therefore highly recommended to verify the aberrant cervicocraniofacial morphology in severe and non-severe OSA patients.