Department of Prosthodontics, Dental School, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil.
Sleep Sector, Neurology Unit, Pedro Ernesto University Hospital, UERJ, Rio de Janeiro, Brazil.
J Sleep Res. 2023 Aug;32(4):e13879. doi: 10.1111/jsr.13879. Epub 2023 Mar 14.
Masticatory muscle activity during sleep has been considered independent of variations in the structural characteristics of the dental occlusion. However, scientific evidence contradicting an occlusal causal role is missing. The purpose of this study was to test the null hypothesis that sleep bruxism (SB) is independent of the presence of occlusal interferences. A total of 17 healthy female subjects (mean [SD] age 24.9 [4.1] years) presenting with SB, and randomly divided into two groups, were evaluated after receiving either elimination of occlusal interferences (Test group) or elimination of sharp margins without change in occlusal contacts (Control group). Audio-video polysomnography (PSG) recordings were undertaken before and after treatment (mean [SD] duration 14.4 [3.8] months). Two subjects in each group (< 2 rhythmic masticatory muscle activity [RMMA]/h) were excluded for statistical analysis. During the total sleep time (TST), the Test group exhibited a higher reduction in frequency of episodes per hour than the Control group (p < 0.05). The reduction in duration of episodes was also higher in the Test group during the TST. The Test group presented an increase in sleep stage N3 (p < 0.05) at the final PSG when compared with the initial PSG, and a higher percentage of N3 (p < 0.05) at the final PSG when compared to the Control group. Elimination of occlusal interferences resulted in a significant reduction of masseter and temporal muscle activity during sleep in females presenting with SB. Based on these results, the null hypothesis is rejected. The hypothesis of occlusal interferences as a risk factor for SB is still patent.
咀嚼肌在睡眠中的活动被认为与牙齿咬合结构特征的变化无关。然而，目前还缺乏科学证据来证明咬合确实与磨牙症存在因果关系。本研究旨在检验磨牙症与咬合干扰无关的零假设。共纳入 17 名女性磨牙症患者（平均[标准差]年龄 24.9[4.1]岁），随机分为两组，一组接受消除咬合干扰（实验组），另一组接受消除锐利边缘但不改变咬合接触（对照组），治疗后评估睡眠时多导睡眠图（PSG）记录（平均[标准差]持续时间 14.4[3.8]个月）。每组有 2 名（<2 个节律性咀嚼肌活动[RMMA]/h）受试者因统计学分析被排除。在总睡眠时间（TST）中，实验组每小时发作频率的减少明显高于对照组（p<0.05）。实验组在 TST 期间发作持续时间的减少也更高。与初始 PSG 相比，实验组在最终 PSG 时睡眠阶段 N3 的时间增加（p<0.05），与对照组相比，实验组在最终 PSG 时 N3 的比例更高（p<0.05）。消除咬合干扰可显著减少女性磨牙症患者睡眠时咀嚼肌和颞肌的活动。基于这些结果，零假设被拒绝。咬合干扰作为磨牙症危险因素的假设仍然成立。
