Development of a Monitor System for Orthodontic Tooth Movement

本研究旨在开发一种基于光学测量牙周韧带血容量的正畸牙齿移动监测系统。采用近红外光谱分析技术，对实验性牙齿移动过程中牙周膜中的总血红蛋白和氧合血红蛋白进行了检测。用25g、50g、100g、250g的正畸力对猫上颌尖牙进行28天的正畸力作用，结果表明：1.正常牙冠加负荷后，总血红蛋白降低，氧合血红蛋白无明显变化。在25g正畸力作用下，牙周膜的血流反应与正常牙周膜的血流反应基本相同。在50g和100g正畸力作用下，总血红蛋白和氧合血红蛋白的变化均显著。在250g正畸力作用下，总血红蛋白和氧合血红蛋白中的PDL无血流反应。50g和100g正畸力样本的牙齿移动速度比其他两个样本快。组织学观察表明，该方法可用于根据PDL代谢活动的数据确定最佳作用力。在临床应用之前，测量系统配备了半导体激光器作为光源。在未施加正畸力的人牙列中，血流反应与动物标本基本相同。

This study was conducted to develop a monitor system for orthodontic tooth movement based on optical measurement of blood volume in periodontal ligaments (PDL). Near infrared spectroscopy was applied to measure total-hemoglobin and oxy-hemoglobin in PDL during experimental tooth movement. Orthodontic force (25g, 50g, 100g, 250g) was applied to the maxillary canine of cats for 28 days.The results were :1. In normal PDL.total-hemoglobin decreased due to the application of load to a tooth crown, while oxy-hemoglobin was unchanged.2. With a 25g orthodontic force, the blood flow response of PDL was almost the same as the normal PDL sample.3. With the 50g and 100g orthodontic force, the changes both in total-hemoglobin and in oxy-hemoglobin were remarkable.4. With a 250g orthodontic force, there was no blood flow response of PDL in total-hemoglobin and oxy-hemoglobin.5. The 50g and 100g orthodontic force samples showed more rapid tooth movement than the others.6. Histological observation suggested that this method was useful in determining the optimal force based on the data for the metabolic activity in PDL.Prior to the clinical application, the measurement system was equipped with a semiconductor laser as a light source. In human PDL without orthodontic force applied, the blood flow response was almost the same as the animal samples.