Wang Mei-Qing, He Jian-Jun, Wang Kelun, Svensson Peter
Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Fourth Military Medical University, Xi'an, China.
Acta Odontol Scand. 2009;67(3):187-92. doi: 10.1080/00016350902794800.
To test whether changes in occlusal support differentially modulate masseter and anterior temporalis muscle electromyographic (EMG) activity during controlled maximal voluntary clenching.
Forty-seven healthy subjects (32 M and 15 F, 22.9+/-1.3 years) were recruited. Cotton-rolls were used to modify the occlusal contact relations and were positioned on the right, left, or both sides, and either in the molar or premolar regions, i.e. six different occlusal combinations. Surface EMG activity was recorded bilaterally from the masseter and anterior temporalis area and normalized with respect to maximal voluntary clenching in the intercuspal position. Analysis of variance and the paired t-test were used to test the data.
Normalized EMG activity was influenced by changes in cotton-roll modified occlusal support, and there were differences between muscles (p<0.001). In general, EMG activity decreased in both muscles when occlusal support was moved from the molar to the premolar region. When occlusal support was moved from bilateral to unilateral contacts, EMG activity in the balancing-side anterior temporalis muscle and in bilateral masseter muscles decreased. Unilateral clenching on the molars, but not on the premolars, was associated with lower EMG activity in the balancing-side masseter and always associated with lower EMG activity in the balancing-side anterior temporalis compared to the working side (p<0.05).
Masseter and anterior temporalis muscles respond differently to changes in occlusal support, which may have implications for stability of the mandible during intense clenching.
测试在控制的最大自主紧咬过程中，咬合支持的变化是否会不同程度地调节咬肌和颞肌前束的肌电图（EMG）活动。
招募了47名健康受试者（32名男性和15名女性，年龄22.9±1.3岁）。使用棉卷改变咬合接触关系，将其放置在右侧、左侧或双侧，以及磨牙区或前磨牙区，即六种不同的咬合组合。从双侧咬肌和颞肌前束区域记录表面肌电活动，并相对于牙尖交错位的最大自主紧咬进行标准化。采用方差分析和配对t检验对数据进行检验。
标准化的肌电活动受棉卷改变的咬合支持变化的影响，且肌肉之间存在差异（p<0.001）。一般来说，当咬合支持从磨牙区移至前磨牙区时，两块肌肉的肌电活动均降低。当咬合支持从双侧接触变为单侧接触时，平衡侧颞肌前束和双侧咬肌的肌电活动降低。与工作侧相比，单侧在磨牙上紧咬（而非在前磨牙上）时，平衡侧咬肌的肌电活动较低，且平衡侧颞肌前束的肌电活动始终较低（p<0.05）。
咬肌和颞肌前束对咬合支持变化的反应不同，这可能对强力紧咬时下颌的稳定性有影响。
