The relationships between cephalometric parameters and severity of obstructive sleep apnea

Objective: To verify the relationships between cephalometric parameters and apnea hypopnea index (AHI) in snoring patients in Chiang Mai University Hospital. Methods: Fifty patients who attend ENT snoring clinic, Faculty of Medicine, Chiang Mai University Hospital during 1 October, 2007 to 31 October, 2008 were enrolled. All subsequently underwent overnight polysomnography by SOMNOCHECK (R) V2.04 and lateral cephalometric radiographs. Results: Of the 50 patients, 78% were men (n = 39) and 22% were women (n = 11). Ages ranged from 31 to 65 years. Average apnea hypopnea index (AHI) = 18.4 +/- 18.2 events/h. Body mass index (BMI) = 27.2 +/- 3.3 kg/m(2). The mean sella-nasion-subspinale (SNA) = 84.1 +/- 4.3 degrees. Sella-nasion-supramental (SNB) = 81.8 +/- 3.4 degrees. Posterior airway space (PAS) = 14.9 +/- 4.3 mm. Distance between mandibular plane and hyoid (MP-H) = 27.7 +/- 5.6 mm. Distance between posterior nasal spine and tip of soft palate (PNS-P) = 42.5 +/- 5.4 mm. Using Pearson's correlation analysis of BMI, the cephalometric parameters from all subjects with AHI revealed BMI, PAS and MP H had significant correlation with AHI; p = 0.009, p = 0.003, and p = 0.005, respectively. BMI, MP H, and PAS were correlated with AHI. The multiple regression model for the effects of BMI, PAS, and MP H on AHI is AHI = 2.090(BMI) - 1.953(PAS) + 1.1333(MP-H) - 40.54. Conclusion: The model seems to be useful as a screening tool to assess the severity of obstructive sleep apnea in snoring patients. (C) 2010 Elsevier Ireland Ltd. All rights reserved.