The Achievement of the Optimal Force in Experimental Orthodontic Tooth Movement

本研究的目的是根据牙周组织的组织学和生物力学方法，研究正畸牙移动时的最佳受力。结果表明：1.在初始正畸力作用下，剩余的退行性组织和骨的再生受到重新调整的正畸力的影响。这一区域是力重新调整后的旋转中心。剩余的变性组织和骨的大小随着时间的推移而减小，但在重新调整期后仍保持不变。建议减少力量或身体活动，以避免倾倒运动。2.退变组织后面的牙槽骨部位广泛观察到后方的骨吸收。这些吸收发生在靠近牙周间隙的穿孔通道内。部分变性组织通过通道的大开口也被观察到。3.血管形态和分布与穿孔通道内压力分布密切相关。4.标本有限元分析显示，退变组织形成于压应力分布峰值附近。该峰的最小值估计大于-35kPa.

The purpose of this sutdy is to investigate the optimal force under orthodontic tooth movement according to the histologic and biomecanical methods in the periodontal tissue. The results obtained were :1.Regeneration of the remaining degenerated tissue and bone under initial orthodontic force was delayd incident to readjusted orthodontic force. And this region was the center of rotation following readjusted force. The remaining degenerated tissue and bone reduced in size with time, but remained after the readjusted period. It is suggested that a reduction in force or bodily movement may be desirable to avoid tipping movement.2.The rear bone resorptions was observed widely at the site of the alveolar bone behind the degenerated tissue. These resorptions occurred in the perforating channels near the periodontal space. A part of the degenerated tissue passing to the large orifices of the channels was also observed. Many blood vessels and osteoclasts were located near the degenerated tissue.3.There is a close relationship between the morphology and distribution of blood vessels with the distribution of pressure in perforating channels.4.The specimen-specific finite element analysis showed that the degenerated tissue was formed around the peak of the compressive stress distribution. The minimum value of the peak was estimated to be more than -35kPa.