Faculty of Dental Medicine and Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan.
Section of Orofacial Pain and Jaw Function, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark.
Headache. 2018 Apr;58(4):559-569. doi: 10.1111/head.13280. Epub 2018 Feb 24.
Repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible, ie, bruxism, is traditionally linked to pain and unpleasantness in the active muscles. The aim of this study was to investigate the effects of standardized craniofacial muscle contractions on self-reported symptoms.
Sixteen healthy volunteers performed six 5-minute bouts of 20% maximal voluntary contraction task of the jaw-closing (Jaw), the orbicularis-oris (O-oris), and the orbicularis-oculi (O-oculi) muscles. Participants rated their perceived pain, unpleasantness, fatigue, and mental stress levels before, during, and after the contraction tasks on 0-10 Numeric Rating Scales (NRS). Each muscle contraction task (= 1 session) was separated by at least 1 week and the order of the sessions was randomized in each subject.
All muscle contraction tasks evoked significant increases in NRS scores of pain (mean ± SD: Jaw; 3.8 ± 2.7, O-oris; 1.9 ± 2.2, O-oculi; 1.4 ± 1.3, P < .014), unpleasantness (Jaw; 4.1 ± 2.5, O-oris; 2.1 ± 1.9, O-oculi; 2.9 ± 1.8, P < .001), fatigue (Jaw; 5.8 ± 2.0, O-oris; 3.2 ± 2.3, O-oculi; 3.6 ± 1.9, P < .001), and mental stress (Jaw; 4.1 ± 2.1, O-oris; 2.2 ± 2.7, O-oculi; 2.9 ± 2.2, P < .001). The Jaw contractions were associated with higher NRS scores compared with the O-oris and the O-oculi contractions (P < .005) without differences between the O-oris and the O-oculi (P > .063). All symptoms disappeared within 1 day (P > .469).
The results showed that submaximal static contractions of different craniofacial muscle groups could evoke transient, mild to moderate levels of muscle pain and fatigue and increased stress scores. The fatigue resistance may differ between different muscle groups. Further studies are warranted to better understand the contribution of specific craniofacial muscle groups for the characteristic presentation of musculoskeletal pain conditions in the head.
以磨牙或下颌紧咬或推压为特征的重复性咀嚼肌活动，即磨牙症，传统上与活动肌肉的疼痛和不适有关。本研究旨在探讨标准化颅面肌肉收缩对自我报告症状的影响。
16 名健康志愿者进行了 6 次 5 分钟的 20%最大自主收缩任务，分别为闭口（Jaw）、口轮匝肌（O-oris）和眼轮匝肌（O-oculi）。参与者在收缩任务前、中、后使用 0-10 数字评分量表（NRS）对感知疼痛、不适、疲劳和精神压力水平进行评分。每个肌肉收缩任务（=1 个疗程）之间至少间隔 1 周，每个受试者的疗程顺序随机。
所有肌肉收缩任务均引起 NRS 评分显著增加，疼痛评分（平均值±标准差：Jaw；3.8±2.7，O-oris；1.9±2.2，O-oculi；1.4±1.3，P<.014）、不适评分（Jaw；4.1±2.5，O-oris；2.1±1.9，O-oculi；2.9±1.8，P<.001）、疲劳评分（Jaw；5.8±2.0，O-oris；3.2±2.3，O-oculi；3.6±1.9，P<.001）和精神压力评分（Jaw；4.1±2.1，O-oris；2.2±2.7，O-oculi；2.9±2.2，P<.001）。与 O-oris 和 O-oculi 收缩相比，Jaw 收缩与更高的 NRS 评分相关（P<.005），而 O-oris 和 O-oculi 之间没有差异（P>.063）。所有症状在 1 天内消失（P>.469）。
结果表明，不同颅面肌肉群的亚最大静态收缩可引起短暂的、轻度至中度的肌肉疼痛和疲劳，并增加应激评分。不同肌肉群的疲劳抵抗力可能不同。需要进一步的研究来更好地理解特定颅面肌肉群对头部肌肉骨骼疼痛特征的贡献。
