Development of new occlusal evaluation system based on peculiarity of tooth vibration during palpation.

我们之前的研究表明，当被触诊的牙齿有一些过早接触时，牙齿在触诊过程中的振动幅度在200 Hz左右逐渐增大，当适当的手指压力（50 ~ 150 gr.）时，牙齿的最大振动幅度可能成为客观咬合评价的新参数。本研究的目的是为了确认咬合评价新参数的可靠性。选取5名志愿者，测量他们的第11、21、13、23、14和24颗牙齿在下颌习惯性闭合运动时的每颗牙齿振动。用多厚度的铂箔分别模拟人工过早接触牙齿11、13和14。但是21号、23号和24号牙齿没有人工过早接触，每个对照牙齿11号、13号和14号都进行了测量。加速度计拾取器用于测量约50g手指压力下的牙齿振动。对各波形进行FFT分析，计算最大振幅和峰值频率。结果表明：各牙过早接触时振动的最大振幅值显著高于对照牙（学生t检验，p<0.01），且峰值频率均在150 ~ 750hz范围内（置信区间为99%）。在此基础上，基于触诊过程中牙齿的振动，建立了一套新的咬合评价系统

Our previous studies indicated that the tooth vibration during palpation showed a growing amplitude around 200 Hz when the palpated tooth had some premature contact, and that the maximum amplitude of tooth vibration might be a new parameter for an objective occulusal evaluation when a suitable finger pressure (from 50 to 150 gr.) was applied. The purpose of this study was to confirm the reliability of the new parameter for occlusal evaluation. Five volunteers were used and each tooth vibration of their #11,21,13,23,14 and 24 teeth was measured during habitual closing movement of the mandible. Artificial premature contact to teeth #11,13 and 14 was simulated individually by a multiple-thickness platinum foil. But no artificial premature contact was given to teeth #21,23 and 24, which was measured for each control tooth #11,13 and 14. The accelerometer pick-ups were used to measure the tooth vibration with about 50 gr.finger pressure. FFT analysis was applied to each wave form of tooth vibration, and then the maximum amplitude and its peak frequency were calculated. The results were as follows : each vibration of the teeth given premature contact showed a significantly higher value in the maximum amplitude than the vibration of each control tooth (Student's t-Test, p<0.01) and also all of the peak frequencies were observed in the range of 150 to 750 Hz (Confidence Interval at the 99%).Then we manufactured a new occlusal evaluation system using these results based upon tooth vibration during palpation