Li J, Jiang T, Feng H, Wang K, Zhang Z, Ishikawa T
Department of Prosthodontics, Peking University School of Stomatology, Beijing, China.
J Oral Rehabil. 2008 Feb;35(2):79-87. doi: 10.1111/j.1365-2842.2007.01750.x.
The aim of the present study was to investigate the short-term impact of an occlusal highspot on the occurrence of orofacial symptoms by collecting self-evaluation and using electromyography (EMG) evaluation. A rigid unilateral intercuspal occlusal highspot (A cast onlay of 0.5 mm) was placed on the right lower first molar of six adult volunteers (three males, three females), and remained for 6 days. Continuously all the induced orofacial symptoms were collected and the subjects scored the orofacial pain on a 10-cm visual analogue scale (VAS) during the placement of onlay. The surface EMG was recorded before the placement of onlay, during (on the 3rd and 6th day) and after the onlay was removed. Then the contractile symmetry of bilateral masseter (MAL, MAR) and anterior temporalis (TAL, TAR) was measured by using an asymmetry index. On the 3rd day of the placement of the occlusal highspot, all subjects complained of headache in right temporal region (mean VAS +/- s.d.=3.7+/-0.5); the activity of TAR at rest position of mandible increased significantly (P=0.027). In addition, on the 3rd and 6th day with the highspot the EMG activity of the tested muscles during maximal voluntary contraction (MVC) was significantly reduced; the asymmetry index of bilateral anterior temporalis during MVC was increased significantly (P(3rd)=0.028; P(6th)=0.046). A unilateral occlusal highspot may make the ipsilateral anterior temporalis become tenser at rest position. Furthermore, the activity of bilateral anterior temporalis becomes more unsymmetrical during MVC although there are inter-individual differences between subjects. The changes in muscular activity may have some relationship with the occurrence of tension-type headache in temporal region.
本研究的目的是通过收集自我评估并使用肌电图（EMG）评估，来调查咬合高点对口腔颌面部症状发生的短期影响。在六名成年志愿者（三名男性，三名女性）的右下第一磨牙上放置一个刚性单侧牙尖交错位咬合高点（0.5毫米的铸造高嵌体），并保留6天。在放置高嵌体期间，持续收集所有诱发的口腔颌面部症状，受试者在10厘米视觉模拟量表（VAS）上对口腔颌面部疼痛进行评分。在放置高嵌体前、放置期间（第3天和第6天）以及移除高嵌体后记录表面肌电图。然后使用不对称指数测量双侧咬肌（MAL，MAR）和颞前肌（TAL，TAR）的收缩对称性。在放置咬合高点的第3天，所有受试者均抱怨右颞部头痛（平均VAS +/-标准差=3.7+/-0.5）；下颌休息位时TAR的活动显著增加（P=0.027）。此外，在有高点的第3天和第6天，最大自主收缩（MVC）期间测试肌肉的肌电图活动显著降低；MVC期间双侧颞前肌的不对称指数显著增加（第3天P=0.028；第6天P=0.046）。单侧咬合高点可能会使同侧颞前肌在休息位时变得更紧张。此外，尽管受试者之间存在个体差异，但在MVC期间双侧颞前肌的活动变得更加不对称。肌肉活动的变化可能与颞部紧张型头痛的发生有一定关系。
