Fitton Laura C, PrôA Miguel, Rowland Charlie, Toro-Ibacache Viviana, O'higgins Paul
Centre for Anatomical and Human Sciences, Department of Archaeology and Hull York Medical School, University of York, York, United Kingdom.
Anat Rec (Hoboken). 2015 Jan;298(1):107-21. doi: 10.1002/ar.23075.
In recent years finite element analysis (FEA) has emerged as a useful tool for the analysis of skeletal form-function relationships. While this approach has obvious appeal for the study of fossil specimens, such material is often fragmentary with disrupted internal architecture and can contain matrix that leads to errors in accurate segmentation. Here we examine the effects of varying the detail of segmentation and material properties of teeth on the performance of a finite element model of a Macaca fascicularis cranium within a comparative functional framework. Cranial deformations were compared using strain maps to assess differences in strain contours and Procrustes size and shape analyses, from geometric morphometrics, were employed to compare large scale deformations. We show that a macaque model subjected to biting can be made solid, and teeth altered in material properties, with minimal impact on large scale modes of deformation. The models clustered tightly by bite point rather than by modeling simplification approach, and fell out as being distinct from another species. However localized fluctuations in predicted strain magnitudes were recorded with different modeling approaches, particularly over the alveolar region. This study indicates that, while any model simplification should be undertaken with care and attention to its effects, future applications of FEA to fossils with unknown internal architecture may produce reliable results with regard to general modes of deformation, even when detail of internal bone architecture cannot be reliably modeled.
近年来，有限元分析（FEA）已成为分析骨骼形态与功能关系的一种有用工具。虽然这种方法对化石标本的研究具有明显吸引力，但此类材料往往支离破碎，内部结构遭到破坏，并且可能含有导致精确分割出现误差的基质。在此，我们在一个比较功能框架内，研究了牙齿分割细节和材料属性的变化对猕猴颅骨有限元模型性能的影响。使用应变图比较颅骨变形，以评估应变轮廓的差异，并采用几何形态计量学中的普氏大小和形状分析来比较大规模变形。我们表明，承受咬合的猕猴模型可以制成实体，并且牙齿的材料属性可以改变，而对大规模变形模式的影响最小。模型按咬点紧密聚类，而非按建模简化方法聚类，并且与另一个物种明显不同。然而，不同的建模方法记录到预测应变大小存在局部波动，特别是在牙槽区域。这项研究表明，虽然任何模型简化都应谨慎进行并关注其效果，但即使无法可靠地对内部骨骼结构细节进行建模，有限元分析在未来应用于内部结构未知的化石时，在一般变形模式方面可能会产生可靠的结果。
