【摘要】 目的:分析下颌骨功能状态下及坚强内固定时的应力分布及应力遮挡作用,为下颌骨骨折治疗提供参考。方法:利用ANSYS软件建立下颌骨颏部骨折及坚强内固定的三维有限元模型。在模型上对下颌骨颏部骨折在骨愈合不同时期及采用不同内固定方法固定时的应力分布进行有限元法分析并评价应力遮挡作用的大小。结果:小型板内固定导致的应力遮挡率随着愈合期变化而逐渐变小;骨折愈合的相同时期,同种材料的接骨板,双板固定时的应力遮挡率大于单板;钢板固定时的应力遮挡率大于钛板。结论:小型接骨板用于下颌骨颏部骨折坚强内固定时,存在明显的应力遮挡作用,接骨板的材料属性、形状大小和固定位置的选择对骨断层的应力遮挡作用有重要的影响。更多还原

【Abstract】 Objective:To study the stress distribution dur i ng clenching and rigid internal fixation(RIF)of mandibular symphysis fracture. Methods:ANSYS software was used to establish the models of mandi bular symphysis fracture and the fracture treatment treat with RIF.The stress di stribution of mandibular symphysis fracture under different conditions were then analysed during different period of bone healthing. The value of stress shieldi ng rate was used to represent the level of stress shielding effects.Resu lts:The stress shielding rate decreased with the progression of fracture healing.The stress shielding rate produced by double plates fixation was higher than that by single plate.Stress shielding rate in the mandible fixed with tita nium plate was lower than that with steel plate.Conclusion:Minip late rigid internal fixation system may produce stress shielding effects when it is used to treat mandibular symphysis fractures. Stress shielding effects are a ffected by the attribute, the shape and the position of the plate.更多还原