Feeling and mental stress when wearing an oral appliance for obstructive sleep apnea syndrome: Comparison of mono-block type and two-piece type

<p>Purpose: A mono-block type oral appliance （OA） that restrains jaw-opening and a two-piece type OA with structure allowing jaw-opening are used for the treatment of obstructive sleep apnea syndrome. The aim of this study was to elucidate the difference between feeling and mental stress when wearing mono-block OA and those when wearing two-piece OA.<br>Materials and Methods: The subjects were twelve healthy volunteers. For each subject, a mono-block OA and a two-piece OA were made at the same mandibular position with a 5-mm bite raising from centric occlusion. Measurements under three conditions （without OA, with mono-block OA and with two-piece OA） were performed for two courses consisted of three nights with interval of two weeks. Salivaα-amylase activity, electrocardiograph （ECG） R-R interval, psychological test, self-assessment score of sleep state and awareness score for preference of use were examined.<br>Results: As for salivaα-amylase activity, ECG R-R interval and psychological test, most subjects with OA didn't show deviated data from the standard range, and there were no significant differences between the data with mono-block OA and those with two-piece OA. Regarding self-assessment score of sleep state and awareness score for preference of use, two-piece OA showed significantly higher values than those of mono-block OA.<br>Conclusion: It was suggested that two-piece OA with structure allowing jaw-opening was superior to mono-block OA in the assessment items （self-assessment score of sleep state and awareness score for preference of use） that were dominantly based on subjective feeling.</p>