Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, 4-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Miyagi, Japan.
Int J Mol Sci. 2022 Mar 9;23(6):2968. doi: 10.3390/ijms23062968.
Micro-osteoperforations (MOPs) have been reported to accelerate orthodontic tooth movement (OTM), and tumor necrosis factor (TNF)-α has been reported to play a crucial role in OTM. In this report, the influence of MOPs during OTM was analyzed. We evaluated the expression of TNF-α with and without MOPs by RT-PCR analysis. A Ni-Ti closed coil spring was fixed between the maxillary left first molar and the incisors as an OTM mouse model to move the first molar in the mesial direction. MOPs were prepared on the lingual side and mesial side of the upper first molars. Furthermore, to investigate the target cell of TNF-α for osteoclast formation during OTM with MOPs in vivo, we created four types of chimeric mice in which bone marrow of wild-type (WT) or TNF receptor 1- and 2-deficient mice (KO) was transplanted into lethally irradiated WT or KO mice. The results showed that MOPs increased TNF-α expression, the distance of tooth movement and osteoclast formation significantly. Furthermore, mice with TNF-α-responsive stromal cells showed a significant increase in tooth movement and number of osteoclasts by MOPs. We conclude that MOPs increase TNF-α expression, and tooth movement is dependent on TNF-α-responsive stromal cells.
微骨穿孔术 (MOPs) 已被报道可加速正畸牙齿移动 (OTM)，肿瘤坏死因子 (TNF)-α 已被报道在 OTM 中发挥关键作用。在本报告中，分析了 MOPs 在 OTM 过程中的影响。我们通过 RT-PCR 分析评估了有和没有 MOPs 时 TNF-α 的表达。在上颌左第一磨牙和切牙之间固定镍钛闭圈弹簧作为 OTM 小鼠模型，以使第一磨牙向近中方向移动。在第一磨牙的舌侧和近中侧制备 MOPs。此外，为了研究 TNF-α 在体内 MOPs 诱导 OTM 过程中破骨细胞形成的靶细胞，我们创建了四种嵌合小鼠，其中野生型 (WT) 或 TNF 受体 1 和 2 缺陷型 (KO) 小鼠的骨髓被移植到致死性辐照 WT 或 KO 小鼠中。结果表明，MOPs 显著增加了 TNF-α 的表达、牙齿移动的距离和破骨细胞的形成。此外，MOPs 使 TNF-α 反应性基质细胞的小鼠牙齿移动和破骨细胞数量显著增加。我们得出结论，MOPs 增加了 TNF-α 的表达，牙齿移动依赖于 TNF-α 反应性基质细胞。
