Finite element modelling of squirrel, guinea pig and rat skulls: using geometric morphometrics to assess sensitivity
Finite element modelling of squirrel, guinea pig and rat skulls: using geometric morphometrics to assess sensitivity
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DOI：
10.1111/j.1469-7580.2011.01436.x
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发表时间：
2011-12-01
影响因子：
2.4
通讯作者：
Jeffery, N.
中科院分区：
文献类型：
--
作者：
Cox, P. G.;Fagan, M. J.;Jeffery, N.
啮齿类动物具有独特的牙列和高度复杂的下颌闭合肌肉排列。有限元分析 (FEA) 是研究这些专业的生物力学影响的理想技术，但必须充分了解 FE 模型不同输入参数的影响程度，才能对模型的预测充满信心。本研究评估了啮齿动物颅骨有限元模型对材料弹性特性、载荷方向以及模型约束的位置和方向的敏感性。用松鼠、豚鼠和大鼠头骨构建了三个有限元模型。每个模型都加载模拟切牙、第一和第三磨牙的咬合，切牙咬合的角度在 45 度范围内变化。骨骼和牙齿组件的杨氏模量在我们自己和之前发布的材料特性测试结果定义的极限之间变化。几何形态测量学（GMM）被用来分析由此产生的头骨变形。研究发现，骨硬度对所有三种啮齿类动物的结果影响最大，其次是咬合位置，然后是咬合角度和肌肉方向。研究表明，牙齿材料特性对头骨变形影响很小。咬合位置的影响因物种而异，咬合牙齿的近远中位置对松鼠和豚鼠来说最重要，而双边咬合与单侧咬合对大鼠的影响最大。对孤立切牙变形的 GMM 分析表明，对于所有啮齿动物来说，咬合角度是最重要的参数，其次是牙齿的弹性特性。这里的结果阐明了在定义有限元模型时哪些输入参数最重要，而且还提供了三个头骨之间生物力学差异的有趣一瞥，这些差异将在未来的出版物中进行充分探讨。
Rodents are defined by a uniquely specialized dentition and a highly complex arrangement of jaw-closing muscles. Finite element analysis (FEA) is an ideal technique to investigate the biomechanical implications of these specializations, but it is essential to understand fully the degree of influence of the different input parameters of the FE model to have confidence in the model's predictions. This study evaluates the sensitivity of FE models of rodent crania to elastic properties of the materials, loading direction, and the location and orientation of the models' constraints. Three FE models were constructed of squirrel, guinea pig and rat skulls. Each was loaded to simulate biting on the incisors, and the first and the third molars, with the angle of the incisal bite varied over a range of 45 degrees. The Young's moduli of the bone and teeth components were varied between limits defined by findings from our own and previously published tests of material properties. Geometric morphometrics (GMM) was used to analyse the resulting skull deformations. Bone stiffness was found to have the strongest influence on the results in all three rodents, followed by bite position, and then bite angle and muscle orientation. Tooth material properties were shown to have little effect on the deformation of the skull. The effect of bite position varied between species, with the mesiodistal position of the biting tooth being most important in squirrels and guinea pigs, whereas bilateral vs. unilateral biting had the greatest influence in rats. A GMM analysis of isolated incisor deformations showed that, for all rodents, bite angle is the most important parameter, followed by elastic properties of the tooth. The results here elucidate which input parameters are most important when defining the FE models, but also provide interesting glimpses of the biomechanical differences between the three skulls, which will be fully explored in future publications.