单侧咬合接触对颞颌关节髁突应力分布的影响

[目的]用三维有限元法探讨单侧咬合接触时对髁突表面应力分布的影响,以期为临床提供有益的参考.[方法]利用所建的下颌骨三维有限元模型, 约束模型颞骨区上表面全部节点的自由度,限制下颌运动;约束后牙咬合面节点和垂直方向的自由度.分别观察单侧（右）第二磨牙区和双侧第二磨牙区加载时,两侧髁状突表面22个区域应力分布变化情况.[结果]双侧加载时在髁突表面产生的负荷,左右侧分布相等对称;单侧加载时,两侧髁状突表面应力分布不对称：工作侧髁突承受的最大拉应力大于非工作侧,而非工作侧髁突表面的最大压应力大于工作侧,非工作侧所有区域的Von Mises应力和最小主应力均大于工作侧.[结论]单侧咬合接触可造成双侧髁突表面应力不对称改变,非工作侧髁突表面产生的负荷大于工作侧,提示临床单侧咬合接触可能是颞下颌关节紊乱综合病的病因之一.

Effect of Unilateral Occlusal Contact on Surface Stress Distribution of Condyle of Temporomandibular Joint

[Objective] To investigate the effect on unilateral occlusal contact on surface stress distribution of condyle of temporomandihular joint by three-dimensional finite element method. [Methods] On the basis of three dimensional finite element of mandible model, condyle surface stress changes were observed under unilateral （right） and bilateral occlusal load. [Results] When the model loaded with bilateral location, the stress was equal on the bilateral condyle surfaces. When the model loaded with unilateral location, the maximum ten- sion stress was larger on the working side than that on the non-working side, but the maximum compressive stress was larger on the non-working side than that on the working side, and the minimum principal stress and Von Mises stress on the non-working side were larger than that on the working side. [Conclusion]Unilateral occlusal contact may result in that bilateral condyle surface stress changes and the load of non-working side is larger than that of working side. It indicates that clinical bilateral occlusal contact may be one of the etiologic factors of temporomandibular joint disorders.