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Smoothness of masticatory jaw movements before and after orthodontic treatment

正畸治疗前后咀嚼颌运动的平滑度

基本信息

批准号：
12671995
负责人：
YASHIRO Kohtaro
金额：
$ 2.05万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

First, we investigated whether the minimum-jerk model predict the 3D jaw movement trajectories during chewing. The two types of test foods were used : gum and gummy jelly. The jaw movements were recorded from children and adults groups with good occlusions. For adults and children groups, the model precisely explained the jaw movement kinematics. Hence, it is suggested that the subjects with normal occlusions may control the jaw movement so as to maximize their smoothness during chewing. However, the jerk-costs of the jaw closing motion for the children were significantly higher than those determined for the adults. In addition, the jerk-cost variation was greater in children than adults. The greater variances of jerk-cost for the children may be the results of variety of the motor adaptation process to the dental developmental changes during childhood with mixed-dentition.Second, the jaw motor adaptation process to the experimentally produced acute occlusal interference was investigated. The unilateral chewing jaw motion with occlusal interference set at the molar site on the contra- lateral side was recorded for adults' volunteers. The jerk-cost showed significant decrease in association with the progress of the motor adaptation. Accordingly, it is confirmed that the jerk-cost may be the useful parameter of evaluating quantitatively the changes in jaw kinematic characteristics during chewing efforts.Finally, the masticatory jaw movements were recorded from the patients with severe skeletal 3 antero-posterior jaw deviations. The results showed significantly higher jerk-costed jaw movements in patients with deviated jaw relationships. Thus, it is suggested that the masticatory jaw motion in subjects with good occlusion may optimize the jaw motion to be more economical than that for the patients with sever malocclusion.

首先，我们研究了最小推力模型是否能预测咀嚼过程中的三维下颌运动轨迹。试验中使用了两种食物：口香糖和胶状果冻。下颌运动记录来自咬合良好的儿童组和成人组。对于成人和儿童群体，该模型准确地解释了下颌运动的运动学。因此，建议咬合正常的受试者可以控制颌骨的运动，以最大限度地提高咀嚼时的平整度。然而，儿童闭合下巴动作的挺举成本明显高于成人。此外，儿童的急诊费用差异比成年人更大。儿童的拔牙成本差异较大，可能是混合牙合儿童对牙齿发育变化的运动适应过程不同的结果。其次，研究了儿童对实验产生的急性咬合干扰的下颌运动适应过程。记录成人志愿者单侧咀嚼下颌运动，咬合干涉设置在对侧磨牙位置。随着运动适应的进展，急救成本显著降低。因此，JUCK-COST可以作为定量评价咀嚼过程中颌骨运动学特征变化的有用参数。最后，记录了严重骨性3前后颌偏斜患者的咀嚼运动。结果显示，颌骨关系偏斜的患者，其抽动成本的下颌运动显著增加。因此，咬合良好的受试者的咀嚼下颌运动可能比严重错牙合患者的咀嚼运动更经济。