Orthodontic examination on correspondence between change in occlusion and periodontal mechanoreceptors-by means of biomechanical, physiological, and immunohistological approaches-

本研究的目的是从生物力学、生理学和免疫组织化学的角度阐明正畸治疗前后牙周膜机械感受器的动态变化.生物力学方法我们改进了以压敏橡胶为核心的咬合力传感器，用于测量整个牙列咬合力的瞬时变化。也就是说，我们设计了一个小尺寸的传感器来逐个测量牙齿。利用光纤传感器间接三维测量上颌中切牙的微小位移。根据外力作用点的不同，牙齿的位移模式也不同，可以观察到牙齿转动中心发生变化的现象。同时，我们用直接接触式微位移装置测量了上颌第一磨牙在紧咬时的位移 ...更多信息 e.说明上下第一磨牙的接触方式不同，导致牙齿移动方式不同.大鼠牙周膜机械感受器的主要神经支配为A δ纤维。与门齿不同的是，它是快速适应型和缓慢适应型的混合体，而在臼齿中只能找到快速适应型。此外，在提取拮抗剂后大鼠牙周膜机械感受器适应性特征的变化中，可以观察到对机械刺激的反应阈值的变化，也可以观察到反应模式比例的变化。此外，在小鼠中，咀嚼所必需的神经传递物质随着生长而变化.免疫组织化学方法：在生后3周的小鼠下切牙上放置一个装置，诱导前牙反牙合，并在2、4、6、8周后取出前牙反牙合诱导装置，用免疫组织化学方法观察Ruffini神经末梢的分布和形态学变化。与诱导前牙反牙合一样，位于上颌前切牙牙周膜腭侧的Ruffini神经末梢退化减少。然而，在这种情况下，前牙反改善后，矫正器被删除，Ruffini神经末梢再生。因此，我们证实了咬合变化与牙周机械感受器之间的对应关系。少

The purpose of this research is to clarify the dynamic change of periodontal mechanoreceptors before and after orthodontic treatment by means of biomechanical, physiological and immunohistological approaches.1. Biomechanical approachWe improved occlusal force sensor (the core of the sensor was a pressure sensitive rubber) which was designed to measure the momentarily changing occlusal force of the whole dentition. That is to say, we devised this sensor of small size to measure tooth one by one. And we measured the occlusal force onto each tooth when functioning.The minute displacement of the maxillary central incisor was measured three dimensionally indirectly with optic fiber sensor. According to different spots where external force Was applied, the pattern of displacement varied, and the phenomenon that center of rotation of the tooth changed could be observed. Also, we measured the displacement of the maxillary first molar when clenching with direct-contact minute displacement devic … More e. It indicated that different contact pattern between the upper and lower first molars resulted in varied tooth displacement pattern.2. Physiological approachThe main innervation nerves of periodontal mechanoreceptors of rats are A delta fibers. In contrast with incisors, of mixed fast-adapted and slowly-adapted types, only fast-adapted types can be found in molars. Moreover, as for the change in adaptive characteristics of periodontal mechanoreceptors of rats after antagonists were extracted, change of threshold in response to mechanical stimulation could be seen, and the change of proportion of reaction patterns could also be observed. Furthermore, in mice, the nerve transmission substances necessary for mastication changed with growth.3. Immunohistological approach2,4,6 and 8 weeks after we set a device onto the lower incisors of mice of 3 weeks old after birth to induce anterior crossbite, and another 2,4,6 and & weeks after the device used for inducing anterior crossbite was removed, we utilized immunohistological method to observe the distribution and morphological change of Ruffini nerve endings by PGP- 9.5. As with anterior crossbite was induced, the Ruffini nerve endings located at the palatal sides of the periodontal membranes of the anterior maxillary incisors degenerated and lessened. However, in the case that anterior crossbite ameliorated after the appliance was removed, Ruffini nerve endings regenerated. Thereby, we confirmed the correspondence between change of occlusion and periodontal mechanoreceptors. Less