Abstract
Purpose: Many reports have described the influence of wearing an oral appliance that is used for dental treatment of obstructive sleep apnea syndrome. However, the morphological change in the oropharyngeal region by wearing a mandibular advancement device has not been fully studied. In this study, the influence of posture and respiratory phases during cephalometric radiograms were investigated, as to the morphological change of the oropharyngeal region in normal subjects.
Methods: Twelve nonsnoring normal subjects (ten males and two females; mean age 27.3 years;body mass index 21.9kg/m2) participated in this study. Cephalometric radiograms were carried out with the subjects either by inspiration or expiration depending on whether in the upright or supine position. Repeated-measures ANOVA was used for comparing the measurement values for the two factors, posture and respiration.
Results: There was no significant difference between the inspiration and the expiration in the oropharynx. However, the area of the pharyngeal cavity and the antero-posterior widths of the middle and the inferior regions of the upper airway significantly decreased by change of body posture from upright to supine. The distance between the hyoid bone and mandibular were significantly decreased from upright to supine position.
Conclusions: The present results clearly indicate that the morphological assessment of the oropharyngeal region by cephalometric radiograms is influenced by posture.
