Development of evaluating system of bruxism by imaging physiological and biochemical characteristics of masticator muscles.

1.在评估磨牙症的特性方面，我们利用医学影像对咀嚼肌的代谢和生理生化特性进行了评估。首先通过MRI判断咬合形态的不同，判断一种咀嚼肌群是否处于活动状态。结论：1.我们认为T2值可以作为判断咀嚼肌动过的指标。我们研究了多普勒超声显示肌肉血流对评价咬肌代谢的作用，以及31P-MR波谱作为医学影像评价咬肌代谢的价值。多普勒超声表现与31P-MR波谱的结果相关联。提示多普勒超声也可以评价肌肉的收缩和疲劳恢复情况。通过咬合判断表观弥散系数(ADC)和T2值的变化是否提示咬肌收缩。ADC对咬合变化敏感。我们建议T2 Valus和ADC可以用来评估肌肉疲劳和伴随磨牙症的损伤。本研究的目的是评估DT MRI能否在静息状态下以及在张开和关闭颌骨的过程中检测到水扩散的变化。MM扩散的特征值对颌骨位置敏感。特定于颌位的肌肉纤维的募集反映了肌肉扩散参数的不同变化。

1. Regarding to assess the properties of bruxism, we evaluated metabolism, and physiological and biochemical characteristics of masticator muscles using medical imaging. At first, it was evaluated whether a kind of mobilized masticator muscles by the difference of occlusal pattern was judged using MRI. We considered that mobilized masticator muscles could be identified using T2 value.2. We studied whether Doppler ultrasonography presenting blood flow in muscle was useful for evaluating the metabolism of masseter muscle as well as 31P-MR spectroscopy which was performed generally for evaluating metabolism of it as medical imaging. Doppler ultrasonograpy presented findings in correlating to ones of 31P-MR spectroscopy. It was suggested that contraction and recovery from fatigue of the muscle could be evaluated using Doppler ultrasonography, also.3. We evaluated whether change of apparant difussin coeficient (ADC) and T2 value by clenching suggested contraction of masseter muscle. ADC was sensitive to changes by clenching. We suggested that T2 valus and ADCs may be used to evaluated muscle fatigue and injuries that accompany bruxism.4. The aim of this study was to assess whether water diffusion changes could be detected by DT MRI performed at rest, and during jaw opening and closure. The eigen values for diffusion of the MM were sensitive to jaw position. Recruitment of muscle fibers, specific to jaw position, reflects the different changes in muscle diffusion parameters.