Uchida Takashi, Sakai Jun, Okamoto Yasuhiro, Watanabe Tsukasa, Kitagawa Tsuyoshi, Aida Masahiro, Saito Takachika, Ito Takanori
Department of Oral Diagnostics, Nihon University School of Dentistry at Matsudo.
Nihon Hotetsu Shika Gakkai Zasshi. 2008 Jul;52(3):350-9. doi: 10.2186/jjps.52.350.
For diagnoses of temporomandibular dysfunction, reports indicate the importance of analyzing jaw movements using a jaw motion tracking device with six degrees of freedom. However, such devices are not widely applied in clinical practice, due to difficulty of use. To determine whether CMS-JAW (a newly developed six degrees of freedom jaw motion tracking device that features easy analysis of jaw movements) offers the measurement accuracy required for clinical use, we evaluated the device by measuring condyle translation and rotation during jaw movement.
In this study, we evaluated measurement accuracy by comparing measurements of condyle movements obtained from the Win Jaw System, a comparable jaw motion tracking device with six degrees of freedom based on an ultrasonic recording system; the Gnathohexagraph II, a device based on a different measurement principle; and the CMS-JAW. In the experiment, we confirmed the condyle translations and rotations obtained by each device by measuring distances and angles, respectively, with a micro slider for three-dimensional measurements (to an accuracy of 0.01 mm and 0.02 mm) and a digital protractor (to an accuracy of 0.1 degrees).
No significant distortions were observed in the space replicated based on the range of condyle translations obtained with CMS-JAW. Deviations from theoretical values were greatest along the z-axis, with a maximum error of 0.20 mm and root mean square (RMS) error of 0.10 mm. The maximum error for angles of condyle rotation was 0.50 degrees; RMS errors ranged from 0.05 to 0.30 degrees.
Our analysis of condyle movement demonstrates that the CMS-JAW provides acceptable measurement accuracy for clinical applications.
对于颞下颌关节紊乱病的诊断，报告指出使用具有六个自由度的下颌运动跟踪装置分析下颌运动的重要性。然而，由于使用困难，此类装置在临床实践中并未得到广泛应用。为了确定CMS-JAW（一种新开发的六个自由度下颌运动跟踪装置，其特点是易于分析下颌运动）是否能提供临床使用所需的测量精度，我们通过测量下颌运动过程中的髁突平移和旋转来评估该装置。
在本研究中，我们通过比较从Win Jaw System（一种基于超声记录系统的具有六个自由度的类似下颌运动跟踪装置）、Gnathohexagraph II（一种基于不同测量原理的装置）和CMS-JAW获得的髁突运动测量值，来评估测量精度。在实验中，我们分别使用用于三维测量的微型滑块（精度为0.01 mm和0.02 mm）和数字量角器（精度为0.1度）测量距离和角度，以确认每个装置获得的髁突平移和旋转。
基于CMS-JAW获得的髁突平移范围复制的空间中未观察到明显变形。沿z轴与理论值的偏差最大，最大误差为0.20 mm，均方根（RMS）误差为0.10 mm。髁突旋转角度的最大误差为0.50度；RMS误差范围为0.05至0.30度。
我们对髁突运动的分析表明，CMS-JAW为临床应用提供了可接受的测量精度。
