Kobayashi H, Ochi K, Saito I, Hanada K, Maeda T
Department of Orthodontics, Niigata University School of Dentistry, Japan.
J Dent Res. 1998 Mar;77(3):503-17. doi: 10.1177/00220345980770031001.
It is known that orthodontic forces induce discomfort and/or abnormal sensation after application of an orthodontic appliance in patients, suggesting the adaptation of periodontal neural elements to environmental changes. However, no morphological data have been provided. The present study investigated, by immunoelectron microscopy, the localization of growth-associated protein-43 (GAP-43) in periodontal Ruffini endings in rat molars during experimental tooth movement. In the untreated control group, immunoelectron microscopy demonstrated that GAP-43-like immunoreactivity in the Ruffini endings was confined to the Schwann sheaths around the axon terminals, and was in neither the cell bodies of terminal Schwann cells nor the axon terminals themselves. Immunoelectron microscopic observation revealed alterations in the localization of GAP-43-like immunoreactivity in the periodontal Ruffini endings during experimental tooth movement. After 1 day of treatment, the cell bodies of the terminal Schwann cells associated with Ruffini endings appeared to contain immunoreaction products for GAP-43, and retained GAP-43-like immunoreactivity during tooth movement. From 5 to 7 days, a major population of the axoplasm of the periodontal Ruffini endings, which was immunonegative in control, filled the GAP-43 immunoreactions, showing a tendency to decrease in number later, and disappeared completely at 14 days. These findings suggest that orthodontic forces easily induce the remodeling of the mechanoreceptive Ruffini endings as well as the active tissue remodeling in a close relationship. Since the ultrastructural localization of GAP-43-like immunoreactivity was drastically changed in the Ruffini endings during tooth movement, GAP-43 functions as one of the key molecules in the remodeling of mechanoreceptive Ruffini endings during tooth movement.
众所周知，正畸力在患者佩戴正畸矫治器后会引起不适和/或异常感觉，这表明牙周神经元件在适应环境变化。然而，尚未有形态学数据报道。本研究通过免疫电子显微镜，研究了实验性牙齿移动过程中大鼠磨牙牙周鲁菲尼末梢中生长相关蛋白43（GAP - 43）的定位。在未处理的对照组中，免疫电子显微镜显示鲁菲尼末梢中GAP - 43样免疫反应性局限于轴突终末周围的施万细胞鞘，既不存在于终末施万细胞的胞体中，也不存在于轴突终末本身。免疫电子显微镜观察揭示了实验性牙齿移动过程中牙周鲁菲尼末梢中GAP - 43样免疫反应性定位的改变。处理1天后，与鲁菲尼末梢相关的终末施万细胞的胞体似乎含有GAP - 43的免疫反应产物，并在牙齿移动过程中保留GAP - 43样免疫反应性。从第5天到第7天，牙周鲁菲尼末梢的轴浆（在对照组中免疫阴性）大量出现GAP - 43免疫反应，随后数量有减少趋势，并在第14天完全消失。这些发现表明正畸力容易诱导机械感受性鲁菲尼末梢的重塑以及与之密切相关的活跃组织重塑。由于在牙齿移动过程中鲁菲尼末梢中GAP - 43样免疫反应性的超微结构定位发生了剧烈变化，GAP - 43在牙齿移动过程中机械感受性鲁菲尼末梢的重塑中起关键分子之一的作用。
