Development of viscoelastic measurement system and histological examination of periodontal ligament and alveolar bone.

在正畸治疗过程中，牙周组织在牙齿运动和固位方面的变化是非常必要的。正畸治疗涉及各种变化，其中，特别是牙齿的活动被认为是反映牙周韧带和牙槽骨的粘弹性，因为他们是正确的。在这项研究中，我们开发了一种新的评估犬牙齿活动度的系统，以便将组织学结果与牙齿活动度进行比较。最小的载荷质量的牙齿是必不可少的，以准确地测量牙齿的流动性。此外，传感器应被调节为打火机或可能的非接触式。在初步实验中，我们检验了激光位移仪（LDM）在模拟模型上测量牙齿移动度的可能性和准确性。然后，在实验犬的第三切牙舌面用载荷力测量位移的量和相位。同时用脉冲锤进行振动，用FFT实时分析仪对振动频率进行分析。仿真模型结果表明，该测量系统的测量精度较高，200g时为2.7%，500g时为1.3%。频率峰值显示在相同的频谱上。在狗的牙齿上，位移量分别为50g时18 mum， 100g时38mum， 200g时47 mum， 500g时65mum，频率峰值为375 -600Hz。综上所述，该系统足够适用于犬正畸牙齿运动中牙齿移动的时间变化。

It is imperative to clarify the changes in periodontal tissues during orthodontic treatment in terms of not only tooth movement but retention. Orthodontic treatment involves various kinds of changes in which, particullary, tooth mobility is said to reflect viscoelastic property of periodontal ligament and alveolar bone as correctly as they are.In this study, a new system for an assessment on a dog's tooth mobility was developed in order to compare histological findings with tooth mobility.Minimization of the loading mass to a tooth is essential for the measurement of the tooth mobility accurately. Furthermore a sensor should be conditioned as a lighter or possibly a non-touched type. In the preliminary experiment we examined the possibility and accuracy of the measurement of tooth mobility on the simulation models using Laser Displacement Meter (LDM).Then, in the experimental dogs, the quantity and phase of displacement were measured with loading forces at the lingual surface of 3rd incisors. At the same time vibration was given by an impulse hammer and the frequency was analyzed by FFT real time analyzer.The results on the simulation models showed high accuracy of this measuring system, which were 2.7% at 200g and 1.3% at 500g. The frequency peaks were shown with the same spectrum.On the dog's teeth the quantities of displacement were 18 mum at 50g, 38mum at 100g, 47 mum at 200g, 65mum at 500g, respectively, with a frequency peak of 375 -600Hz.In conclusion it was suggested that this system is suitable enough to investigate the temporal changes in tooth mobility in orthodontic tooth movement in dogs.