MANDIBULAR POSTURE DURING SLEEP IN HEALTHY-ADULTS

To test whether the mandible opens more during deep sleep and whether the mandibular position is affected by body position during sleep, the vertical mandibular position was recorded intraorally using a magnet sensor at the same time as a standard sleep study in seven normal heal thy male adults. Measurements were recorded during the period before s leep onset (WAKE) and during sleep. Two-way ANOVA showed that vertical mandibular position was significantly affected by sleep stage but not by body position (supine vs lateral recumbent). The proportion of tim e during which the mandible was in a near-closed position (0-2.5 mm) s ignificantly and progressively decreased, and significantly more time was spent at wider gapes (2.5-5 mm) as non-rapid-eye-movement (NREM) s leep deepened. In REM sleep, the proportion of time during which the m andible was at wider gapes was significantly greater than in WAKE and stage 1 (but not later stages) of NREM sleep. It was concluded that ma ndibular posture during sleep in healthy adults is significantly influ enced by sleep stage but not by body position. Mandibular opening prog ressively increases with the depth of NREM sleep stage, and the mandib le is more open in REM sleep than in light NREM sleep, (C) 1998 Elsevi er Science Ltd. All rights reserved.