Hu Xiao-ying, Dong Fu-sheng, Lu Hai-yan, Ma Wen-sheng, Yuan Shuo
Department of Orthodontics, College of Stomatology, Hebei Medical University, Shijiazhuang 050017, China.
Department of Oral and Maxillofacial Surgery, College of Stomatology, Hebei Medical University, Shijiazhuang 050017, China. Email:
Zhonghua Kou Qiang Yi Xue Za Zhi. 2013 Oct;48(10):600-5.
To develop a child craniofacial three-dimensional (3D) finite element model (FEM) with sutures defined alone.
The CT data for this study was developed from sequential computed tomography scan images taken at 0.625 mm intervals of an 8 years children skull. Data set was imported into Mimics 10.0 and processed with Geomagic 9.0, and exported as initial graphics exchange specification(IGES) files. The IGES files were then imported into Ansys 13.0 to set up two FEM with or without the median palatine suture being opened. The FEM contained nine craniofacial sutures and eight teeth which were defined alone.For simulating orthopedic maxillary protraction, three forces (F1-F2) were loaded on FEM.F1(1 N) was loaded at 1 cm above the geison. F2(1 N) was loaded at articular fossa of temporal bone. F3(2 N) was directed anteriorly and paralleled with occlusal plane near the canine. The stress distribution and the values distributed in each point gained in the two models were compared.
Two craniofacial 3D FEM of the child were developed with the median palatine suture opened or not .With median palatine suture being opened or not, the two models showed the similar von Mises stresses (VMS). The distribution of the VMS was in the bridge of the nose and dextro-ala nasi.When the median palatine suture was opened, the max VMS value was 18916.00×10(-4) MPa which appeared in the nose point and the min VMS value was 1.61×10(-4) MPa which appeared in the maxillary central incisor point. At the same time, the max stress value at the direction Y was -3985.30×10(-4) MPa and appeared in the frontomaxillary suture point, and the min Y value was 0.08×10(-4) MPa which appeared in the maxillary central incisor point. When the median palatine suture was not opened, the max VMS value was 19 244.00×10(-4) MPa and appeared in the nose point. The min VMS value was 1.62×10(-4) MPa and appeared in the maxillary central incisor point. At the same time, the max stress value at the direction Y was -4258.20×10(-4) MPa and appeared in the frontomaxillary suture point, and the min Y value was 0.08×10(-4) MPa which appeared in the maxillary central incisor point.
To define the sutures as entities alone contributed to develop child craniofacial 3D FEM which consist nine sutures. There was tiny difference in stress distribution in both the VMS and in Y direction with the median palatine suture being opened or not.
构建仅定义缝合线的儿童颅面部三维（3D）有限元模型（FEM）。
本研究的CT数据来自于对一名8岁儿童颅骨以0.625mm间隔进行的连续计算机断层扫描图像。数据集被导入Mimics 10.0并使用Geomagic 9.0进行处理，然后导出为初始图形交换规范（IGES）文件。接着将IGES文件导入Ansys 13.0，建立两个有限元模型，一个是打开腭中缝的，另一个是未打开腭中缝的。有限元模型包含单独定义的九条颅面部缝合线和八颗牙齿。为模拟正畸上颌前牵引，在有限元模型上施加三个力（F1 - F2）。F1（1N）施加在鼻根上方1cm处。F2（1N）施加在颞骨关节窝处。F3（2N）向前并与尖牙附近的咬合平面平行。比较两个模型中获得的应力分布以及各点的应力值。
构建了两个儿童颅面部3D有限元模型，一个打开腭中缝，另一个未打开。无论腭中缝是否打开，两个模型的冯·米塞斯应力（VMS）相似。VMS分布于鼻梁和右侧鼻翼。当腭中缝打开时，最大VMS值为18916.00×10⁻⁴MPa，出现在鼻点；最小VMS值为1.61×10⁻⁴MPa，出现在上颌中切牙点。同时，Y方向的最大应力值为 - 3985.30×10⁻⁴MPa，出现在额上颌缝点；最小Y值为0.08×10⁻⁴MPa，出现在上颌中切牙点。当腭中缝未打开时，最大VMS值为19244.00×10⁻⁴MPa，出现在鼻点。最小VMS值为1.62×10⁻⁴MPa，出现在上颌中切牙点。同时，Y方向的最大应力值为 - 4258.20×10⁻⁴MPa，出现在额上颌缝点；最小Y值为0.08×10⁻⁴MPa，出现在上颌中切牙点。
将缝合线单独定义为实体有助于构建包含九条缝合线的儿童颅面部3D有限元模型。腭中缝打开与否，VMS和Y方向的应力分布差异微小。
