Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan.
Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry, Osaka, Japan.
J Oral Rehabil. 2024 Jan;51(1):131-142. doi: 10.1111/joor.13474. Epub 2023 Apr 27.
Sleep on the first night in a sleep laboratory is characterized by a lower sleep quality and frequency of rhythmic masticatory muscle activity (RMMA) than that on the second night in moderate to severe sleep bruxism (SB) patients.
The aims of this study was to clarify the physiological factors contributing to the first night effect on oromotor activity during sleep and investigate whether physiological factors involved in the first night effect differed between rhythmic and non-rhythmic oromotor activities.
Polysomnographic data collected on two consecutive nights from 15 moderate to severe SB subjects (F 7: M 8; age: 23.2 ± 1.3 [mean ± SD] years) were retrospectively analysed. Sleep variables, RMMA and non-specific masticatory muscle activity (NSMA) were scored in relation to episode types (i.e. phasic or tonic and cluster or isolated), sleep architecture and transient arousals. The relationships between nightly differences in oromotor and sleep variables were assessed. The distribution of oromotor events, arousals, cortical electroencephalographic power, RR intervals and heart rate variability were examined in relation to sleep cycle changes. These variables were compared between the first and second nights and between RMMA and NSMA.
Sleep variables showed a lower sleep quality on Night 1 than on Night 2. In comparisons with Night 1, the RMMA index increased by 18.8% (p < .001, the Wilcoxon signed-rank test) on Night 2, while the NSMA index decreased by 17.9% (p = .041). Changes in the RMMA index did not correlate with those in sleep variables, while changes in the NSMA index correlated with those in arousal-related variables (p < .001, Spearman's rank correlation). An increase in the RMMA index on Night 2 was found for the cluster type and stage N1 related to sleep cyclic fluctuations in cortical and cardiac activities. In contrast, the decrease in the NSMA index was associated with increases in the isolated type and the occurrence of stage N2 and wakefulness regardless of the sleep cycle.
Discrepancies in first night effect on the occurrence of RMMA and NSMA represent unique sleep-related processes in the genesis of oromotor phenotypes in SB subjects.
在睡眠实验室的第一晚，与中度至重度磨牙症（SB）患者的第二晚相比，睡眠质量和节律性咀嚼肌活动（RMMA）的频率较低。
本研究旨在阐明导致睡眠期间口颌运动第一晚效应的生理因素，并研究参与第一晚效应的生理因素是否在节律性和非节律性口颌运动之间存在差异。
回顾性分析了 15 名中度至重度 SB 患者（F7：M8；年龄：23.2±1.3[均值±标准差]岁）连续两晚的多导睡眠图数据。与发作类型（即相性或紧张性和簇状或孤立性）、睡眠结构和短暂觉醒相关，对睡眠变量、RMMA 和非特异性咀嚼肌活动（NSMA）进行评分。评估了口颌运动和睡眠变量的夜间差异之间的关系。检查了口颌运动事件、觉醒、皮质脑电图功率、RR 间期和心率变异性与睡眠周期变化的关系。将这些变量与第一晚和第二晚进行比较，并与 RMMA 和 NSMA 进行比较。
与第二晚相比，第一晚的睡眠变量显示出较低的睡眠质量。与第一晚相比，第二晚 RMMA 指数增加了 18.8%（p<0.001，Wilcoxon 符号秩检验），而 NSMA 指数减少了 17.9%（p=0.041）。RMMA 指数的变化与睡眠变量的变化无关，而 NSMA 指数的变化与与觉醒相关的变量的变化相关（p<0.001，Spearman 等级相关）。第二晚 RMMA 指数的增加与皮质和心脏活动睡眠周期性波动相关的簇状类型和 N1 期有关。相比之下，NSMA 指数的减少与孤立型和 N2 期和觉醒的发生有关，与睡眠周期无关。
RMMA 和 NSMA 的第一晚效应差异代表了 SB 患者口颌运动表型发生中的独特睡眠相关过程。
