STUDY ABOUT TISSUE CHARACTARIZATION ON MASTICATORY MUSCLES USING UTRASONOGRAPHY

为了研究咀嚼肌的肌电活动，我们采用超声组织定征技术，对11例颅下颌畸形患者（12 ~ 32岁）和4例正常志愿者进行了研究。采用超声图像评价两侧肌肉横截面厚度和回声水平。这些测量是在咬合、紧握和休息时进行的。7.5使用MHz探头进行实时诊断检查。结果表明，正常人在最大咬合时咬肌厚度增加，两侧回声水平降低。然而，在畸形的受试者中，观察到厚度和回声水平的左右差异。结果提示，咀嚼肌的厚度和回声反射值的变化是评价咀嚼肌活动的重要指标。下颌骨畸形的受试者表现出咀嚼过程中生物力学应力的不平衡，这在正常受试者中不明显。临床前诊断和治疗计划需要定量和可视化的方法来评估功能障碍。我们的超声诊断方法在这项研究中描述了提出了一些解决方案，在这个试验中，故障可视化和评估清楚。在未来，这些诊断技术将被用来获得大量的临床有用的信息，并提高静态特性和动态功能的综合评价。

In order to investigate the muscle activity in masticatory muscles, we developed tissue characterization technique using ultrasonography.Eleven subjects (12 to 32 years old) with craniomandibular deformities and four normal volunteers were studied. Muscle cross-sectional thickness and echo levels were evaluated in both side with ultrasound images. These measurements were carried out when biting, clenching and rest position. 7.5 MHz probe was used for real-time diagnostic examination. From the results, in normal subjects, thickness of masseter muscle increased at maximum biting and showed lower echo level in both side. However, in deformed subjects, left-right differences were observed in thickness and echo level. These findings suggested that the activity of masticatory muscles were evaluated by their changes of thickness and echo reflected value. The subjects with mandibular deformities demonstrated an imbalance in the biomechanical stresses during chewing not evident in the normal subjects. Quantitative and visible methods for evaluating the malfunctions have been needed for pre-clinical diagnosis and treatment planning. Our ultorasonographic diagnosticmethod described in this study proposed some kinds of solution, In this trial, malfunctions were visualized and evaluated clearly. In future, these diagnostic techniques will be used to derive a great deal of clinically useful information and to improve the combined evaluation of both static characteristics and dynamic function.