多层螺旋CT在建立上颌骨三维有限元模型中的应用

目的：为了能够提高牙颌组织有限元分析研究的水平，拟探讨利用多层螺旋CT获取上颌骨扫描数据，进而快速地建立高精度的上颌骨三维有限元模型的方法。 方法：2004—07采用西安市中心医院多层螺旋CT对1名上下颌牙列缺失经全口义齿修复已1年，上颌牙槽嵴宽大丰满的男性进行头面部扫描，利用专业造型软件完成三维实体模型的重建，并在此基础上建立完整无牙颌上颌骨及颅骨的三维有限元模型。 结果：获取了精确的头面部多排螺旋CT扫描断层影像数据，利用所得数据建立了63360个节点、38879个单元的无牙颌上颌骨计算机模拟全口义齿修复三维有限元模型．完整重现了上颌骨复杂的形态，得到了上颌骨、颈骨、颅骨以及上颌窦．眶腔等结构鲜明、直观的印象。 结论：利用多层螺旋CT扫描数据建立上颌骨三维有限元模型，无需描记轮廓线、插层等人工操作，能够尽可能地排除人为的干扰，既缩短了建模时间，又提高了所建立模型的精度。

Application of mnitislice helical CT in the construction of three-dimensional finite element model of maxillary bone

AIM： Based on multislice helical CT （MSCT） scanning data, this paper aimed to develop an effective and precise method to construct three- dimensional （3-D） finite element （FE） model of maxillary, so as to raise the level of jaw tissue FE analysis.
METHODS： In July 2004, the experiment adopted one male patient from Xi ＇an Central Hospital, who suffered from the loss of both maxillary and mandible dentia by complete denture for one year, with the plump alveoli dentals maxillae crest. According to the data of head and face scanning, 3-D solid model was reconstructed by professional molding software, and then 3-D FE models of complete edentulous jaw maxillary and cranial bone were established.
RESULTS： With the fault image data of precise MSCT scan on head and face, the 3-D FE model of edentulous maxillary including 63 360 nodes and 38 879 units was established to imitate the complete denture repair, and duplicate the complicated shape of maxillary, and obtain the structural and macroscopic impressions on maxillary bone, malar bone, cranium, maxillary sinus and orbital cavity.
CONCLUSION： The application of MSCT in the construction of 3-D FE model of maxillary bone is feasible and effective. It can not only shorten the time of modeling and raise the precision of models, but also eliminate the artificial interference as marly as possible. In addition, MSCT does not require manual operations, such as the contour line tracing and intercalation.