Functional Morphology and Evolution Unit, Hull York Medical School, University of York, UK.
J Anat. 2011 Jan;218(1):75-86. doi: 10.1111/j.1469-7580.2010.01257.x.
Whilst the periodontal ligament (PDL) acts as an attachment tissue between bone and tooth, hypotheses regarding the role of the PDL as a hydrodynamic damping mechanism during intraoral food processing have highlighted its potential importance in finite element (FE) analysis. Although experimental and constitutive models have correlated the mechanical function of the PDL tissue with its anisotropic, heterogeneous, viscoelastic and non-linear elastic nature, in many FE simulations the PDL is either present or absent, and when present is variably modelled. In addition, the small space the PDL occupies and the inability to visualize the PDL tissue using μCT scans poses issues during FE model construction and so protocols for the PDL thickness also vary. In this paper we initially test and validate the sensitivity of an FE model of a macaque mandible to variations in the Young's modulus and the thickness of the PDL tissue. We then tested the validity of the FE models by carrying out experimental strain measurements on the same mandible in the laboratory using laser speckle interferometry. These strain measurements matched the FE predictions very closely, providing confidence that material properties and PDL thickness were suitably defined. The FE strain results across the mandible are generally insensitive to the absence and variably modelled PDL tissue. Differences are only found in the alveolar region adjacent to the socket of the loaded tooth. The results indicate that the effect of the PDL on strain distribution and/or absorption is restricted locally to the alveolar bone surrounding the teeth and does not affect other regions of the mandible.
虽然牙周韧带 (PDL) 作为骨与牙之间的附着组织，但关于 PDL 在口腔内食物加工过程中作为流体动力阻尼机制的作用的假说强调了其在有限元 (FE) 分析中的潜在重要性。尽管实验和本构模型已经将 PDL 组织的机械功能与其各向异性、非均质性、粘弹性和非线性弹性特性相关联，但在许多 FE 模拟中，PDL 要么存在要么不存在，而且存在时的建模方式也不同。此外，PDL 占据的空间较小，并且无法使用 μCT 扫描可视化 PDL 组织，这在 FE 模型构建过程中带来了问题，因此 PDL 厚度的协议也各不相同。在本文中，我们最初测试和验证了猕猴下颌骨 FE 模型对 PDL 组织杨氏模量和厚度变化的敏感性。然后，我们通过使用激光散斑干涉法在实验室中对同一下颌骨进行实验应变测量来测试 FE 模型的有效性。这些应变测量与 FE 预测非常吻合，这表明材料特性和 PDL 厚度得到了适当的定义。FE 应变结果在整个下颌骨中对 PDL 组织的缺失和不同的建模通常不敏感。差异仅在加载牙齿的牙槽区域附近发现。结果表明，PDL 对应变分布和/或吸收的影响仅限于牙齿周围的牙槽骨，不会影响下颌骨的其他区域。
