Abstract
Purpose: The purpose of this study was to evaluate an appropriate jaw opening by an oral appliance for patients with obstructive apnea syndrome.
Methods: Eighteen normal dentulous subjects without stomatognathic function were enrolled in this study. The subjects were divided into two groups (low ODI group: 13, high ODI group: 5) by Oxygen Desaturation Index (ODI) (cut-off score=5). To assess the changes in ventilation, the forced inspiratory flow (FIF25-75) was measured using a spirometer for four kinds of jaw opening (0 mm, 5 mm, 10 mm and 15 mm) with the position of 50% jaw protrusion. The airway morphology of all the subjects was also imaged by magnetic resonance imaging for the same four kinds of jaw opening and centric occlusion as a control. The upper airway volume from the upper point of the soft palate to the base point of the epiglottis and the antero-posterior distance of the upper airway at the most posterior point of the soft palate were measured and evaluated.
Results: Although FIF25-75 increased with jaw opening in both groups, a similar tendency for airway volume was not observed. There was no statistically significant difference between the two groups. In addition, the volume change of the upper airway occurred mainly at the upper part.
Conclusions: It is suggested that it is better to decrease unnecessary jaw opening to reduce discomfort for OSAS patients.
