UPRIGHT AND SUPINE CEPHALOMETRIC EVALUATION OF OBSTRUCTIVE SLEEP-APNEA SYNDROME AND SNORING SUBJECTS

Specific craniofacial characteristics are reported to occur with obstr uctive sleep apnea syndrome (OSAS). The purpose of this study was to d etermine whether craniofacial morphology differs between subjects with OSAS and heavy snorers, and to investigate how change in posture from upright to lying down affects the upper airway passage. Lateral head radiographs of ten persons diagnosed with OSAS(AHI > 50) and ten snore rs matched for age, height and weight without any history of daytime s leepiness, doctor-diagnosed OSAS, and no evidence of significant desat uration on overnight oximetry were obtained in both upright seated and awake supine positions. The posterior superior pharyngeal space in bo th the OSAS and snorers was reduced when changing from upright to supi ne posture (p less-than-or-equal-to 0.05). Significant differences in cranial base alignment, ramus width relative to the middle-cranial fos sa, position of the maxilla relative to the cranial base in the seated position (P less-than-or-equal-to 0.01) were noted between subjects w ith OSAS and subjects with snoring and less severe apnea. In addition, differences in the posterior superior pharyngeal space, tongue length , tongue to intermaxillary area ratio and hyoid position (p less-than- or-equal-to 0.05) were demonstrated both in the upright and in the sup ine positions (p less-than-or-equal-to 0.05) in the OSAS compared to t he snoring group. These results suggest that anatomic factors may pred ispose some snorers to develop OSAS. Measurements made from awake supi ne position lateral head radiographs revealed no additional difference s between OSAS and snoring subjects when compared to measurements made on radiographs taken in the upright position.