The effect of bruxism on periodontal function

磨牙症患者的牙周感和牙齿移位可能与非磨牙者不同，因为夜间可能会对牙齿施加过大的咬合力。为探讨磨牙症对磨牙区牙周感觉和牙齿移位的影响，将14名受试者分为非磨牙组和磨牙组。夜间咀嚼肌肌电活动证实为磨牙症。牙周感觉是根据牙间触觉阈值进行评估的，该阈值指的是牙齿咬合面之间可以检测到的最小厚度。随机放置金属箔片测量左右两侧第一磨牙区的牙合间触觉阈值，分3天每天测量两次(上午和下午)。磨牙症(有或无)作为受试者间的影响，一天中的时间(上午和下午)和侧面(左侧和右侧)作为受试者内的影响进行多变量方差分析(α=0.05)。多变量方差分析显示，两组患者的咬合间触觉阈值在上午和下午之间或左右两侧之间没有显著差异。磨牙组的平均牙间触觉阈值为17.1±3.9μm，而非磨牙组的牙周触觉阈值为2 9.9±5.6μm(P<0.0 1)。用二维牙位移计测量上颌第一磨牙切牙过程中的牙位移量。对于磨牙者和非磨牙者，牙齿移位的方向没有差异。与非磨牙组相比，磨牙组的位移量更大。

Periodontal sensation and tooth displacement in individuals with bruxism may differ from those in non-bruxers, as excessive amounts of ocdusal force may be applied to the teeth during the night. The purpose of this study was to investigate the effects of bruxism on periodontal sensation in the molar region and tooth displacement.Fourteen subjects were divided into the non-bruxers (n=7) and the bruxers (n=7). Bruxism was confirmed based on the nocturnal electromyography activities of the masseter musde. Periodontal sensation was assessed based on interocdusal tactile threshold, which refers to the minimal thickness that can be detected between the occlusal surfaces of the teeth. Interocdusal tactile threshold was measured in the first molar region each for the left and right sides by randomly placing metal foils, and was measured twice daily (morning and afternoon) on 3 separate days. Multivariate analysis of variance was performed for bruxism (with or without) as a between-subjects effect, and time of day (morning and afternoon) and side (left and right) as within-subjects effects (α=.05) Multivariate analysis of variance revealed no significant differences in interocdusal tactile threshold between morning and afternoon or between the left and right sides in either group. Mean interocdusal tactile threshold for the bruxers was 17.1 ± 3.9 μm, while that for the non-bruxers was significantly greater at 29.9 ± 5.6 μm (P<001).The periodontal sensation in bruxers was increased compared to non-bruxers.Six subjects were divided into the non-bruxers (n=3) and the bruxers (n=3). Tooth displacement during denching were measured in the maxillary first molar using two dimensional tooth displacement transducer. For both the bruxers and non-bruxers, there were no differences in the direction of tooth displacement. When compared with the non-bruxers, the amount of displacement was tend to be higher in the bruxers.