构建上颌第一磨牙及牙周支持组织的有限元模型

Construction of a finite element model for the maxillary first molar and the periodontal tissue

背景:有研究表明有限元方法可较好的模拟结构复杂、形状不规则物体的生物力学分析,其中有限元模型的相似性对研究结果具有重要影响,但理想模型的建立却是有限元研究中最耗时且最复杂的内容。目的:建立上颌第一磨牙及牙周支持组织有限元模型,为上颌第一磨牙进行生物力学研究提供基础。方法:选取一位上下颌牙列完整、牙周组织健康的志愿者。拍摄锥形束CT,图像保存为DICOM格式。将图像导入医学建模软件Mimics中,建立上颌第一磨牙及牙槽骨平面模型;再将该模型导入有限元前后处理软件Gi D中进行处理,建立出完整的上颌第一磨牙及牙周支持组织三维有限元模型。结果与结论:建立包括双侧上颌第一磨牙及其牙周膜和上颌牙槽骨有限元模型,共896 035个节点,4 881 067个单元。此模型还原了受试者上颌第一磨牙及其牙周支持组织的几何外形和解剖结构。结果显示,实验成功构建了上颌第一磨牙及牙周支持组织有限元模型,可以作为各种临床正畸力作用下对上颌第一磨牙及其牙周支持组织生物力学分析研究的基础。

BACKGROUND：Studies have shown that the finite element method could preferably simulate the biomechanical analysis for the object with complicated structures and irregular shapes. The similarities for the finite element model have great influences on the results of the analysis. However, to construct an ideal model is the most time-consuming and complicated portion for the finite element analysis. OBJECTIVE：To construct a finite element model for the maxilary first molar and the periodontal tissue, and to provide a basis of biomechanical researches of the maxilary first molar. METHODS： A volunteer with complete mandibular dentition and healthy periodontal tissue was selected in this study. Cone-beam CT was scanned. The images were saved as DICOM format. These images were imported to the medical modeling software Mimics. The surface model for the maxilary first molar and the alveolar bone was constructed. The model was then imported to GiD for pre-processing. Thus, the complete three-dimensional finite element model for the maxilary first molar and the periodontal tissue was constructed. RESULTS AND CONCLUSION：A finite element model for bilateral maxilary first molar, periodontal ligament and maxilary alveolar bone was constructed, including 896 035 nodes and 4 881 067 elements. This model has restored the geometric shape and the structure of the research object. This study successfuly constructed finite element models of maxilary first molar and the periodontal tissue, which can be a basis of biomechanical researches for the maxilary first molar and the periodontal tissue under the effect of different clinical orthodontic forces.