Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, USA.
Anat Rec (Hoboken). 2010 Sep;293(9):1477-91. doi: 10.1002/ar.21203.
The biomechanical significance of cranial sutures in primates is an open question because their global impact is unclear, and their material properties are difficult to measure. In this study, eight suture-bone functional units representing eight facial sutures were created in a finite element model of a monkey cranium. All the sutures were assumed to have identical isotropic linear elastic material behavior that varied in different modeling experiments, representing either fused or unfused sutures. The values of elastic moduli employed in these trials ranged over several orders of magnitude. Each model was evaluated under incisor, premolar, and molar biting conditions. Results demonstrate that skulls with unfused sutures permitted more deformations and experienced higher total strain energy. However, strain patterns remained relatively unaffected away from the suture sites, and bite reaction force was likewise barely affected. These findings suggest that suture elasticity does not substantially alter load paths through the macaque skull or its underlying rigid body kinematics. An implication is that, for the purposes of finite element analysis, omitting or fusing sutures is a reasonable modeling approximation for skulls with small suture volume fraction if the research objective is to observe general patterns of craniofacial biomechanics under static loading conditions. The manner in which suture morphology and ossification affect the mechanical integrity of skulls and their ontogeny and evolution awaits further investigation, and their viscoelastic properties call for dynamic simulations.
灵长类颅骨缝合线的生物力学意义尚不清楚，因为其整体影响尚不清楚，而且其力学性能难以测量。在这项研究中，在猴子颅骨的有限元模型中创建了 8 个代表 8 个面部缝合线的缝合线-骨功能单元。假设所有的缝合线都具有相同的各向同性线性弹性材料特性，在不同的建模实验中会有所不同，代表融合或未融合的缝合线。这些试验中使用的弹性模量值跨越了几个数量级。在切牙、前磨牙和磨牙咬合条件下评估每个模型。结果表明，未融合的缝合线允许头骨发生更多的变形，并经历更高的总应变能。然而，远离缝合线的部位的应变模式仍然相对不受影响，并且咬合反作用力也几乎不受影响。这些发现表明，缝合线的弹性不会实质性地改变通过猕猴头骨的载荷路径或其下刚性体运动学。这意味着，如果研究目的是观察静态载荷条件下颅面生物力学的一般模式，那么对于小缝合线体积分数的头骨，省略或融合缝合线是一种合理的建模近似，只要有限元分析的目的是观察静态载荷条件下颅面生物力学的一般模式。缝合线形态和骨化如何影响颅骨的机械完整性及其个体发生和进化，这有待进一步研究，而它们的粘弹性特性则需要进行动态模拟。
