Abstract:
Objective To evaluate the lateral cephalometric parameters in a group of Thai patients with severe obstructive and primary snoring. Materials and methods This study was performed in the lateral cephalograms of 190 patients attending Snoring Clinic at King Chulalongkorn Memorial Hospital during 2003-2007. Using the respiratory disturbance index (RDI), the patients were divided into two groups, those with an RDI of five events/hour or below (primary snoring group) and those with an RDI of 30 events/hour or over (severe OSAS group). Their demographic data, along with nine parameter data from lateral cephalograms, were collected. Analyses of the data were performed by a descriptive statistic analysis and an independent t-test at a 95% confident level. Results Parameters with significant differences between primary snoring and severe OSAS groups were SNA and MP-H among male patients, and UT-PhW and MP-H among female patients. Analyses of all data illustrated that a combination of multiple parameters was necessary to classify each patient group. Male patients with severe OSAS were classified by a combination of six parameters (SNA, SNB, MP-H, UT-PhW, UT-PNS, and ATA-PNS), while female patients with severe OSAS by a combination of five parameters (SNA, UT-PhW, UT-PNS, ATA-PNS, and MP-H). Conclusion Lateral cephalograms revealed differences between patients in severe OSA and those in primary snoring groups. Male patients with severe OSAS possessed a maxilla with a retrognathic position, together with a hyoid bone with an inferiorly displaced position. Female patients with severe OSAS possessed a narrower space between tip of uvula and posterior pharyngeal wall, together with a hyoid bone with an inferiorly displaced position. Combinations of parameters from lateral cephalograms were necessary for the classification of patients with severe OSAS