Cephalometric analysis in patients with obstructive sleep apnea. Part I: diagnostic value

Morphological soft-tissue and skeletal anomalies of the upper extrathoracic airways are considered to be an etiological cofactor of nocturnal obstructive respiratory disorders. In this study 106 patients with a mean age of 56.1 +/- 8.4 years and a polysomnographic diagnosis of obstructive sleep apnea (OSA) were evaluated roentgenocephalometrically for soft-tissue and skeletal anomalies. Using cluster analysis and multivariate regression analysis, 18 skeletal variables, six pharyngeal variables and five hyoid variables were evaluated as predictor variables under the criterion variable "severity of the disorder". The body mass index (BMI), as a recognized risk factor of OSA, was taken separately into account. No direct correlation was found between the skeletal cephalometric findings and severity of OSA. Only the position of the hyoid as an expression of a probably adaptive alteration to a changed head posture and tongue position was found to be a significant parameter correlating with the severity of OSA. Whether cephalometric radiography is of direct diagnostic relevance in the diagnosis of OSA seems questionable in the light of the results of the present study.