Three-dimensional relationship between pharyngeal airway and maxillo-facial morphology.

In this study, to clarify the influence of the maxillo-mandibular bones and cranium on airway morphology, maxillo-facial morphology in patients with jaw deformation was measured using cephalograms and X-ray CT imaging data. Subjects consisted of 25 adult women in whom cephalograms and X-ray CT were taken to diagnose jaw deformation. The data obtained were classified based on skeletal and facial patterns according to Ricketts analysis, and changes in internal diameter, height and volume of the middle pharyngeal airway were observed. The results showed that the internal diameter of the inferior airway expanded anteriorly when the mandibular bone was in the anterior position, and was slightly constricted and elongated vertically when the mandibular bone was posteriorly rotated. This suggests that airway volume is influenced by the anteroposterior position of the mandibular bone, in that it compensates for decreases in its volume by extending its height inferiorly to cope with posterior deviation of the mandibular bone.