Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand.
Department of Orthodontics, University of Otago, Dunedin, New Zealand.
Clin Oral Investig. 2021 Aug;25(8):5049-5059. doi: 10.1007/s00784-021-03816-9. Epub 2021 Feb 6.
To examine the relationship between masticatory muscle activity (MMA), self-reported oral behaviours (OBs) and overall physical activity (PA) in adult women.
MMA and PA were assessed by a wearable electromyography (EMG) device and accelerometer respectively, worn over 2 non-consecutive days by 53 women (mean age 27.5 ± 6.4 years). Following the second recording day, self-reported OBs were assessed. MMA was assessed by the number, amplitude and duration of masseter contraction episodes. Masseter muscle EMG outcome measures were number of contraction episodes per hour (CEs/h) and the relative contraction time (RCT%). PA was assessed by time accumulated in moderate to vigorous physical activity (MVPA) and 10-min bouts of MVPA per hour. Data were analysed using mixed model analysis.
MMA in free-living conditions consisted mostly of low-amplitude (<10% maximum voluntary clenching) and short-duration (<10 s) contraction episodes. Masseter CEs/h were not associated with self-reported levels of OB. Masseter CEs/h were positively associated with time accumulated in MVPA (F = 9.9; p = 0.002) and negatively associated with 10-min bouts of MVPA/h (F = 15.8; p <0.001). RCT% was not significantly associated with either.
Objectively assessed MMA is not associated with self-reported OB in free-moving adult females. Moderate to vigorous exercise and physical inactivity are accompanied with an increase in the number of masseter muscle contractions and thus possibly tooth clenching activity.
OB can be influenced by the type and extent of PA. Subjective assessment of MMA by questionnaire and/or interviews may be invalid.
研究咀嚼肌活动（MMA）、自我报告的口腔行为（OBs）与成年女性总体身体活动（PA）之间的关系。
通过佩戴可穿戴肌电图（EMG）设备和加速度计，在 2 个非连续的日子里，分别对 53 名女性（平均年龄 27.5 ± 6.4 岁）进行 MMA 和 PA 评估。在第二天的记录后，评估自我报告的 OBs。MMA 通过评估咀嚼肌收缩发作的次数、幅度和持续时间来评估。咀嚼肌 EMG 结果测量为每小时收缩发作次数（CEs/h）和相对收缩时间（RCT%）。PA 通过中等到剧烈体力活动（MVPA）和每小时 10 分钟的 MVPA 积累时间来评估。使用混合模型分析进行数据分析。
自由生活条件下的 MMA 主要由低幅度（<10%最大随意咬紧）和短持续时间（<10 s）的收缩发作组成。咀嚼肌 CEs/h 与自我报告的 OB 水平无关。咀嚼肌 CEs/h 与 MVPA 积累时间呈正相关（F = 9.9；p = 0.002），与 10 分钟 MVPA/小时的爆发呈负相关（F = 15.8；p <0.001）。RCT%与两者均无显著相关性。
在自由移动的成年女性中，客观评估的 MMA 与自我报告的 OB 无关。中等强度至剧烈运动和身体活动不足伴随着咀嚼肌收缩次数的增加，因此可能伴随着咬牙活动的增加。
OB 可能受到 PA 的类型和程度的影响。通过问卷和/或访谈对 MMA 的主观评估可能是无效的。
