【摘要】 目的　用三维有限元法分析前伸下颌骨的作用机制。方法　在建立的包括TMJ的下颌骨三维有限元模型上 ,模拟下颌前伸 :0 8cm× 0 4cm和 0 4cm× 0 2cm ,采用Su perSAP(93)非线性有限元分析软件进行计算和分析。结果 :①不同程度的下颌前伸不能改变髁突软骨表面的应力分布趋势 ,仅改变应力值的大小 ,即前伸范围越大 ,应力值也相应增大 ,即使水平向 4mm和垂直向 2mm的移位亦能产生相当大的VonMises应力值 ;②不同程度的下颌前伸不能改变髁突的前下位移和伴有一定的顺时针向旋转位移趋势 ;③在下颌前伸时嚼肌深层、颞肌中后束和颈突下颌韧带具有明显的约束作用。结论　提示临床咬合重建时下颌前伸距离不宜太大 ,必要时应分次为宜。更多还原

【Abstract】 Objective To analysis the mechanism of the mandibular protraction therapy by means of the three-dimensional finite element method.Methods The three-dimensional finite element model of mandi-ble, including TMJ, was constructed.To simulate mandibular protractions: 0.8 cm×0.4 cm and 0.4 cm×0.2 cm. Stress and displacement were executed with the finite element program Super SAP(93). The Von Mises stresses and the displacement on the surface of condylar cartilage were investigated.Results ① Two stress distribution trends of the Von Mises on the surface of the condylar cartilage were the same.But the Von Mises when mandible advance 0.8 cm and down 0.4 cm was larger than it when mandible advance 0.4 cm and down 0.2 cm. And it had enough large Von Mises stresses when mandible advance 0.4cm and down 0.2 cm.② The displacement of mandible, including condyle, showed a tendency of rotating clockwise when it advance 0.8 cm and down 0.4 cm, or it advance 0.4 cm and down 0.2 cm. ③The stomatologic muscles functions, especially deep masseter muscle , middle and posterior temporal muscles, and stylomandibular ligament had obrions effect inhibiting mandible advancement. Conclusion The results indicate that the mandibular advancement is should not be too large in clinic.更多还原