Development of analyzing system in temporomandibular joint sound for TMD diagnosis

人们普遍认为，检查颞下颌关节（TMJ）的声音通常可以提供有价值的信息，了解TMJ内部是否存在或程度紊乱，而直接视觉是不可能的。近年来，对用传声器或加速度传感器录制的TMJ声音进行了FFT处理和定量分析，如观察功率谱的变化规律和计算累积频率值。然而，由于每个被试给出的模式不同，且正常被试也存在TMJ音频率分量，因此TMJ音定量评价对颞下颌紊乱（temporomandibular disorder， TMD）诊断的有用性尚未得到证实。因此，在本研究中，我们试图开发一种新的诊断系统，可以方便地记录下颌运动的TMJ声音，方便快速地分析，并可以轻松地确定私人牙科诊所的正常或异常声音。根据本研究结果，我们可以建立TMD患者TMJ音的诊断体系。该系统由记录、分析和评价系统组成。记录系统可以同时记录习惯开/关周期TMJ声音和下颌运动，分析系统可以快速计算TMJ声音的原始波、下颌运动发生点、功率谱、累积频率值、总功率值和每50 Hz各功率值，评价系统可以利用每50 Hz各功率值产生的雷达图直观地比较和评价TMJ声音的特性。将该系统应用于TMD的检查、诊断和治疗，可通过对TMJ声音的客观、定量分析来反映TMD的病理。

It is well believed that examining temporomandibular joint (TMJ) sound would often give valuable information on the existence or degree disorder in the internal part of TMJ where direct vision is impossible. Recently TMJ sound recorded with microphone or acceleration sensor FFT treated and were quantitatively analyzed such as observing the patterns of power spectra and calculating the cumulative frequency values. However, due to the fact that each subject gave different pattern, and the fact that even normal subject had TMJ sound frequency component, the usefulness of quantitative evaluation of TMJ sound has not been confirmed for diagnosis of temporomandibular disorder (TMD).Thus in this study, we attempt to develop new diagnostic system that can easily record TMJ sound with mandibular movement, easily and rapidly analyze, and easily determine normal or abnormal sound in private dental office.From the results in this study, we could establish the diagnostic system for TMJ sound of TMD patient. The system consists of recording, analyzing and evaluating systems. The recording system can simultaneously record TMJ sound and mandibular movement during habitual open/close cycle, the analyzing system can rapidly calculate the raw wave, the occurrence point on mandibular movement, power spectra, cumulative frequency values, total power value and each power value every 50 Hz of TMJ sound, and the evaluating system can visibly compare and evaluate the property of TMJ sound using the radar chart produced from each power value every 50 Hz.By making use of this new system in examination, diagnosis and management for TMD, the pathology of TMD could be represented by objective and quantitative analysis of TMJ sound.