Orthodontic Treatment Outcomes in Jaw Motor Function Evaluated by Jerk-costs of Masticatory Jaw Movements

(1)对于下颌前突的成人咀嚼颌运动，与咬合良好的成年人相比，运动平稳性受损（运动猛跳代价值较高）和峰值速度较低。(2)任意一个平面可以解释每次咀嚼循环中99%的颌部运动轨迹。与可接受良好咬合的受试者相比，前交叉咬合受试者代表每个咀嚼周期的平面方向变化更大。然而，在矫正前交叉咬合后，患者组的平面方向变异性减少。基于最小方差理论，我们认为前交叉咬合矫正后记录的口香糖咀嚼周期具有平滑和良好的模式。(3)提出了一种新的测量算法，能够灵敏地监测语音发音过程中下颌运动的平滑度。(4)为了量化和诊断颞下颌障碍对咀嚼颌运动功能的影响程度，建立了基于抽动优化准则的分析模拟。(5)在病例报告中，已经证明对前牙突和前交叉咬合患者进行正畸治疗可以实现口香糖咀嚼运动学的优化。最小抽动模型的预测精度和归一化的抽动代价都表明了该模型对爪部运动学的改善。

(1)As regard to chewing jaw movements for adults with mandibular prognathism, impairment of the movement smoothness (higher values of the movement jerk-cost) and lower peak velocity have been determined as compared to those for the adults with acceptably good occlusaion.(2)An arbitrary plane could explain 99% of jaw movement trajectory in each single chewing cycle. The orientations of the planes that represent each chewing cycle performed by the subjects with anterior cross bite were more variable than those observed in subjects with acceptable good occlusion. After correction of the anterior cross bite, however, the variability of the plane orientations for the patients group was reduced. Based on a minimum variance theory, it is suggested that the gum-chewing cycle recorded after correction of the anterior cross bites is characterized as smooth and well patterned.(3)An new measurement algorithm, which is capable of sensitive monitoring of the smoothness of the jaw movement in speech articulation, has been developed.(4)Analytical simulation based on jerk-optimal criterion was developed in order to quantify and diagnose extent to which temporomandibular disorder affect the masticatory jaw motor function.(5)In case reports, it has been demonstrated that optimization of gum-chewing kinematics could occur as a result of orthodontic treatment of patient with prognathism and anterior cross bite. The improvement of the jaw kinematics was indicated by both normalized jerk-cost and prediction accuracy of the simulation by the minimum-jerk model.