基于CBCT图像的颌骨及牙列有限元建模方法研究

Study on finite element modeling approach of mandible with full dentition based on CBCT images

目的:研究基于锥形束CT(CBCT)图像的颌骨及牙列的高效三维有限元建模方法。方法:选取1名男性志愿者,用CBCT进行下颌骨扫描,将获取的DICOM格式数据在Mimics17软件中进行三维重建,将三维重建结果以. stl格式导入Geomagic Warp 2015软件中,分别建立由三角面片构成的牙列、牙周膜与牙槽骨三维模型。采用自由网格划分算法,以单元最小内角取25°为约束条件将三角面片模型网格划分,得到由10节点四面体单元构成的颌骨及牙列三维有限元模型。结果:建立了人体完整下颌骨及牙列的三维有限元模型,模型节点总数为299286,牙齿、牙周膜和牙槽骨的单元数分别为105805、122427和577529。结论:基于CBCT影像资料快速建立人体颌骨及牙列三维有限元模型的建模方法稳定性好、精度高、适用范围广。

Objective: To explore an efficient method for the establishment of 3D finite element model based on CBCT images. Methods: Mandible of a male volunteer was scanned by CBCT,and the resulting DICOM data was used for 3D reconstruction in Mimics17 software. Then with the. stl format file,the result of 3D reconstruction was imported into Geomagic Warp 2015,in which 3D models consisting of triangular patches for dentition,periodontal ligament and alveolar bone were created. With free meshing algorithm,the 3D finite element model of mandible with full dentition consisting of 10-node tetrahedron elements was obtained under the constraint that the maximum inner angle was set to be 25°. Results: The 3D finite element model for human mandible with full dentition was established. The total number of nodes is 299286,the elements number for dentition,periodontal ligament and alveolar bone are105805,122427 and 577529,respectively. Conclusion: The proposed method can be used for the establishment of 3D finite element model of mandible with full dentition based on CBCT images,and it has the merits of good stability,high precision and wide application compared with the traditional modeling method.