功能性矫治器引导下颌前伸对其咀嚼肌生物力学特性的影响

Study on biomechanical characteristic of masticatory muscles after mandibular functional protrusion in rat

目的：探讨在功能性颌骨矫形过程中，咀嚼肌生物力学特性变化的规律。方法：选用３０只４周龄Ｗｉｓｔａｒ雄性大鼠，多为实验组和对照组，实验组每日戴功能矫治器１０ｈ～１２ｈ，对照组不戴。４周后应用力学测试方法对嚼肌、二腹肌前腹、翼外肌生物力学特性的变化进行定量分析。结果：咀嚼肌收缩性质发生明显变化，翼外肌收缩张力增强，收缩速度减慢，二腹肌前腹收缩张力减弱，收缩速度加快。结论：表明功能性矫治器是通过改变翼外肌、二腹肌等口颌系统肌肉的功能活动，促进颌骨生长改建，从而达到功能性颌骨矫形目的。

Objective: To study the effects of functional appliance on the biomechanical characteristics of masticatory muscles. Methods: The contracton force and speed of the mastiatory muscles were measured in 30 growing Wistar rats before and after the application of functional appliane.Results: After treatment with the appliance the contraction tension of lateral pterygoid muscles was increased while the speed decreased; the contraction force of digastric muscles was decreased while the speed increases.Conclusion: The functional appliance is effective in the orthopedic treatment due to its function on the biomechanic activity of masticatory muscles.