【摘要】 目的　探讨骨性开牙合和骨性深覆牙合的下颌应力分布、影响因素及其病因联系。方法　通过尸体解剖建立两种错牙合的下颌二维有限元应力分析模型 ,按照轴对称原理 ,在力系分析基础上进行模拟加载 ,比较下颌应力状况并进行相关因素分析。结果　①咬合瞬间骨性开牙合和骨性深覆牙合的下颌应力存在明显差异 ,与骨性深覆牙合者相比 ,开牙合者升支前缘及乙状切迹区呈现更高水平拉应力 ,而下颌角、角前切迹区压应力水平亦显著增高。②下颌形态是影响下颌应力的主要因素 ,咀嚼肌方向的作用很小。结论　形态变异导致的下颌表面应力差异可能是导致骨性开牙合者与骨性深覆牙合者下颌骨表面生长改建不同的原因。更多还原

【Abstract】 Objective To investigate the mandibular stress of the vertical facial dysplasias,the related factors and etiopathological sense.Methods The mandibular stress of the skeletal open-bite and deep overbite walocclusions were compared and three related factors were checked by means of FEM based on a preceding cadaver dissection and force analysis.Results ①The mandibular stress were much different between the two types when biting.Much higher tension ran along the anterior border of the ramus and higher compress went through gonion to the antigonial notch in open-bite type than that in deep overbite one. ②The mandibular morphology had main influence on the stress of mandible while the muscle orientation had little.Conclusion It suggested that varied mandibular stress due to differential morphology might be the cause of different mandibular remodeling of the vertical facial dysplasias.更多还原