STUDY ABOUT TISSUE CHARACTARIZATION ON MASTICATORY MUSCLES USING UTRASONOGRAPHY

为了研究咀嚼肌的肌肉活动，我们开发了基于超声的组织定征技术。11名年龄在12-32岁的颅颌畸形患者和4名正常志愿者被研究。用超声图像评价双侧肌肉的横断面厚度和回声水平。这些测量是在咬合、咬合和休息姿势下进行的。采用7.5 MHz探头进行实时诊断检查。结果表明，正常人最大咬合时咬肌厚度增加，双侧回声水平降低。然而，在畸形受试者中，观察到左侧和右侧在厚度和回声水平上的差异。这些结果表明，咀嚼肌的活动可通过其厚度和回声反射值的变化来评价。有下颌畸形的受试者在咀嚼过程中表现出生物力学应力的不平衡，这在正常受试者中并不明显。临床前诊断和治疗计划需要定量和可见的方法来评估故障。本研究描述的超声诊断方法提出了几种解决方案，在本试验中，故障得到了清晰的可视化和评估。在未来，这些诊断技术将被用来获得大量的临床有用信息，并提高静态特征和动态功能的联合评估。

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.