The influence of craniofacial structure on obstructive sleep apnea in young adults.

PURPOSE: This study compares craniofacial measurements of lateral cephalometric radiographs of young obstructive sleep apnea patients with those of nonapneic snorers and controls. PATIENTS AND METHODS: Forty-eight patients (BM=28.0+/-3.8) with obstructive sleep apnea, 25 patients (BMI=26.3+/-3.5) with nonapneic snoring, and 54 controls (BMI=24.8+/-2.7) were evaluated. All subjects were between 18 and 40 years of age. Nineteen lateral cephalometric measurements were performed by a single investigator blinded to the results of the polysomnograms.
RESULTS: Univariate logistic regression analysis of the 19 variables showed significantly increased midfacial height (ANS-N), narrowed middle airway space (MAS), steep mandibular plane angle (FMA), elongated pharynx (PNS-Eb), and inferiorly positioned hyoid bone (PNS-H, MP-H) in the obstructive sleep apnea group. The nonapneic snoring group showed only a tendency toward maxillary and mandibular retrognathia (SNA and SNB). No significant differences were found for cranial base angle (S-N-Ba), PAS, inferior airway space, maxillary unit length (ANS-PNS) mandibular unit length (Cd-Gn), tongue height (Tng-Ht), soft palate length (PNS-P), and palatal vault height (Ocl-Pal 6). The OSA group was also found to have multiple sites of abnormality of both the upper and lower pharynx, with 58% of the patients having two or more abnormal values (1 standard deviation from the mean) as opposed to 40% of the nonapneic snoring group.
CONCLUSIONS: Highly significant craniofacial abnormalities were found in the upper and lower pharynx in young obstructive sleep apnea patients. Most of these patients (58%) had abnormalities in both the upper and lower pharynx, suggesting that palatal surgery alone may be an inadequate treatment. This information may define future investigations needed to determine how to more effectively treat this subgroup of young obstructive sleep apnea patients.