Cephalometric analysis in patients with obstructive sleep apnea syndrome.

Cephalometry is useful as a screening test for anatomical abnormalities in patients having obstructive sleep apnea syndrome. In this study, various conventional parameters in cephalometry, such as the distance and angles determining the oropharyngeal space, and the areas of the soft palate, oral cavity, tongue and pharynx in both posterior-anterior and lateral view X-ray films, were measured before and after surgery in order to evaluate the preoperative predictability and usefulness of uvulopalato-pharyngoplasty and/or midline laser glossectomy (MLG) for the purpose of preoperative assessment and evaluation of surgical treatment. As test subjects, American adult patients with disturbed respiration in sleep observed at Oakland Otology and Apnea Clinic during 1989-1992 and Japanese patients with the same problems observed at Kitasato Univ. Hospital during 1992-1994 were used. The results were as follows: i) cephalometry revealed morphological abnormalities in the skull, and the measurement of soft tissue in the oropharynx provided useful anatomical data to assess the space of the upper airway in each patient before operation; ii) the areas of the soft palate, the whole tongue and the lower half of the tongue were significantly enlarged, and the lengths of MPH, SPL and PNS-H were longer in the apnea group than in the snoring group; iii) in MLG patients, increases in the area of the oral cavity and pharyngeal cavities and a decrease in the area of the upper half of the tongue were observed.