上下颌骨及牙列三维有限元模型的建立

3-D reconstruction and FEA modeling of jaws and dentition

目的 利用计算机实现正常人部分上颌骨、下颌骨和上下牙列的三维实体造型,并生成有限元模型。方法 在多参数软件Pro/Engineering及Power Shape平台上,将通过CT断层扫描技术及层切法获得的颌骨及牙列的数据进行三维重建以及整体图像拟合,得到上下颌骨及牙列的三维实体模型。应用Ansys大型有限元分析软件建立上下牙列(包括部分上颌骨、完整下颌骨)及牙列缺损和相应修复后状况的三维有限元模型,并对缺失状态的不同修复方式进行了比较。结果 获得了上颌骨(部分)、下颌骨及上下牙列的三维实体模型,建立了上下牙列(包括部分上颌骨、完整下颌骨)及牙列缺损(肯氏Ⅰ、Ⅱ、Ⅲ、Ⅳ类缺损)和相应修复后状况的三维有限元模型,并通过对缺失状态的修复方式的比较实验,验证了该模型的可靠性。结论本实验建立的上下颌骨及牙列的三维实体模型及有限元模型具有较好的几何与力学相似性,由此证实该建模方式是切实可行的。

Objective To perform three dimensional (3-D) reconstruction and establish FEA model of the jaws and dentition with the assistance of the computer. Methods The data of the jaws and dentition by CT scanning and the precise contour of occlusional surface of the teeth by. layer scan were analyzed and reconstructed at the platform of Pro/ engineering (PTC Co., USA) and Power shape (DELCAM Co., UK). 3-D reconstruction model was obtained by matching the above images. Ansys soft ware was applied to establish the 3-D finite element model of the jaws, dentition, the denture (for Kennedy' s type I-IV) and the supporting tissues. Further study was done to compare the stress distribution on different designs of the unilateral distal-extension removable partial dentures (5678 were missing). Results The 3-D stimulated models of jaws, dentition, denture and supporting tissues as well as the 3-D finite element model of dentition and dentition defects (Kennedy's I-IV types) and the dentures were established. The comparison of different designs for left lower distal free extensions verified the reliability of the above established model. Conclusions According to the above method, the 3-D finite element model of jaws and dentition were established with quitegood similarity in geometry and mechanics. The study verified the modeling method is feasible and effective.