Experimental Study of the Effects on Premature Contact involving Masticatory Activity

对涉及咀嚼活动的过早接触影响的实验研究

• 批准号: 05671720
• 负责人: MIURA Hiroyuki
• 金额: $ 1.41万
• 依托单位: Iwate Medical University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05671720/
• 关键词: premature contact; activity of masticatory muscles; EMG; periodontal membrane; stimulation pressure; 咀嚼筋; 歯根膜反射

Malocclusion and CMD (Craniomandibular Disorder) are occasionaly attributable to abnormal mandibular movement due to premature contact. The results of earlier studies revealed that a periodontal membrane reflection recurred from premature contact which affected the excitability of the masticatory muscle. Thereby revealing a relatively earlier formation of this reflection and its eventual disappearance. Then we examined the effects of the difference in stimulation with the loading pressure on the periodontal membrane.We studied 14 teeth consisting of bilateral upper and lower first molars, first pre-molars, canines, right upper and lower central incisors in adults who had no particular abnormalities in the teeth arrangement, occlusion and temporomandibular joint. We attempted to clarify the variation in masticatory muscular activities when 1 Kg of stimulation pressure was exerted from three different directions, buccal to lingual, lingual to buccal and to tooth axis for one second. We s … More et 3 different stimulation pressures for muscle activities, these being 5,10 and 15 Kg under clenched conditions.When stimulation pressure was given to the periodontal membrane at rest, an excitatory electric discharge from the muscle was induced in most cases. However, muscular electric discharge was inhibited when stimulation pressure was added at a 10 Kg clenching force condition. Both induction and inhibition were recognized when the clenching force was 5 Kg. When the clenching force was around 5 Kg it was conceivably a borderline for the excitatory reflection to switch over to an inhibitory reflection. It is considered that this reversal phenomenon adjusts the masticatory movement as follows : subjects would like to bite more strongly at the masticatory muscle is still weaker on mastication, and to inhibit the masticatory muscular excitation reflectively at the masticatory muscle is already strong enough when the stimulation pressure is added to the periodontal membrane.On the other hand, the direction of stimulation pressure concerning the periodontal membranous reflect showed an inhibitory reflection without causing an excitatory reflection when the stimulation pressure was loaded from the maxillolingual side. On the other hand, it was made clear that an excitatory reflection was recognized in the stimulation pressure from the lingual side when the mandibular teeth were involved, and there was a stimulant direction in the periodontal membrane.As a result of this study it was suggested the possibility that the information on periodontal membrane by stimulation pressure give variety to the excitability of mastication muscle and then exert a varid influence upon mandibular movement. Less

错（牙合）畸形和颅下颌紊乱病（Craniomandibular Disorder，CMD）是由于过早接触导致下颌运动异常而引起的。早期的研究结果显示，牙周膜反射复发过早接触，影响咀嚼肌的兴奋性。从而揭示了这种反射的相对较早的形成及其最终的消失。在此基础上，我们研究了14颗牙齿，包括双侧上下第一磨牙、第一前磨牙、尖牙、右上中切牙和右下中切牙，这些牙齿在牙齿排列、咬合和颞下颌关节方面没有特殊的异常。我们试图阐明当从三个不同方向，颊舌，舌颊和牙轴施加1公斤的刺激压力1秒钟时，咀嚼肌活动的变化。我们 ...更多信息 当刺激压力为5、10和15Kg时，肌肉活动在静息状态下可诱发兴奋性放电，当刺激压力为5、10和15Kg时，肌肉活动可诱发兴奋性放电。然而，当刺激压力增加到10公斤的紧握力条件下，肌肉放电被抑制。当紧握力为5Kg时，既有诱导作用，又有抑制作用。当握紧力为5公斤左右时，可以想象，这是兴奋反射转换为抑制反射的边界。据认为，这种逆转现象调整咀嚼运动如下：受试者想要在咀嚼肌处更强烈地咬合，但咀嚼时仍然较弱，并且当刺激压力被施加到牙周膜时，在咀嚼肌处反射性地抑制咀嚼肌兴奋已经足够强。另一方面，当刺激压力从上舌侧加载时，与牙周膜反射有关的刺激压力的方向显示出抑制性反射，而不引起兴奋性反射。另一方面，当涉及下颌牙时，在来自舌侧的刺激压力中识别出兴奋性反射，本研究结果提示，压力刺激牙周膜的信息可能改变咀嚼肌的兴奋性，从而对咀嚼肌的兴奋性产生不同的影响在下颌运动时。少