下颌角截骨整形手术前后下颌骨生物力学的三维有限元分析

目的 通过建立下颌角截骨整形手术前后下颌骨的三维有限元模型,模拟分析手术前后咬合工况和下颌骨受外力撞击工况下颌骨的生物力学变化.方法 选取1例咬合关系正常的女性下颌角肥大患者,手术前后分别行三维CT检查,采集DICOM数据,利用改进的Mimics软件读取DICOM数据进行三维重建并转化为IGES格式后输入ANSYS10.0软件,牛成有限元模型的面、体和三维网格,设置边界约束条件和前处理条件后进行咬合工况和撞击工况的有限元分析.结果 下颌角截骨整形手术后在咬合工况和撞击工况下,下颌骨的最大应力值和最大应力分布范围与术前相比基本一致,但是应力的时间一位移曲线与术前有一定差异.结论 下颌角截骨整形手术后,下颌骨的应力传导时相发生一定变化,但是对正面撞击的耐受程度与术前无明显差异.

3-dimensional finite elements vitodynamics analysis for mandible after mandibular angle osteotomy

Objective To investigate the changes of mandibular vitodynamics in powerful bite working condition and impact working condition after mandibular angle osteotomy through 3-dimensional finit element analysis.Methods A patient of prominent mandibualr angle without malocclusion was selected and underwent 3-dimensional CT before and after operation.The DICOM data of 3-dimensional CT were read by Mimics software and 3-dimensional images were reconstructed.Then the 3-dimensional images were changed into IGES format and imported into ANSYS10.0.The boundary constrained condition and pre-processing condition was setting in ANSYS10.0 software.The 3-dimensional finite element models were generated in ANSYSI0.0.Solution process was running and most powerful bite working condition and impact working condition were simulated and calculated.Results In static stress analysis,the stress peak and stress maximal value point of mandible were basically at equal pace in preoperative and postoperative models.In transience dynamic stress analysis,although stress discrepancies were found in part time point and some region of mandible between preoperative model and postoperative model,the direction and topography of main stress were basically at equal pace.Main stress distributed beside external oblique line and concentrates at the neck of condyle.There was no significant difference of stress conduction and distribution between preoperative and postoperative models.Conclusions Compared with preoperative model,postoperative model has different transduction phases of stress,but has almost the same tolerance extents of main stress.