不同垂直距离下无牙颌髁突应力分布的三维有限元研究.doc

不同垂直距离下无牙颌髁突应力分布的三维有限元研究
作者:安虹,马婷婷,白乐康,黄莺
【摘要】目的探讨无牙颌患者在不同垂直距离下髁突的应力分布特征。方法采用螺旋CT断层扫描技术,经图像数字化处理等方法构建无牙颌患者配戴不同垂直高度全口义齿时下颌骨和颞下颌关节三维有限元模型,分析载荷状态下髁突的应力分布状况。结果不同垂直距离时,髁突每个区域拉、压应力并存,分布趋势基本一致,但不同部位的应力值相差较大,随垂直距离降低(由H2位到H6位),各区应力值呈减小趋势,在H8位时各区应力值呈增大趋势。结论在同等载荷情况下,垂直距离的改变对无牙颌各区域产生不同的应力效果。
【关键词】无牙颌颞下颌关节髁突有限元应力分析
ABSTRACT: Objective To find the characteristics of stress distribution on condyle during different vertical distances of edentulous jaw. Methods Three dimensional finite element models of the mandible and temporomandibular joint were established with plete dentures in different heights by helixCT scanned transverse sections. The stress distribution of the condyle was analyzed under load. Results pressive stress and tensile stress coexisted on the whole condyle with the different vertical distances. The trend of distribution was consistent practically, but the stress presented a large difference on different locum. With the decrease of the ver
tical distance (from H2 to H6), the stress presented a decreasing trend but an increasing trend at H8. Conclusion Changes in the vertical distance produce different effects of stress on edentulous jaw under the same load.
KEY WORDS: edentulous jaw; temporomandibular joint; condyle; finite element method; stress analysis
很多研究认为,多种临床因素可改变髁突在关节凹内的位置及颞下颌关节(temporomandibular joint, TMJ)内的力学环境,使髁突发生应力变化,引发骨改建或病理性损伤。在全口义齿修复过程中,垂