Kober C, Stübinger S, Hellmich C, Sader R, Zeilhofer H F
College for Applied Sciences, Faculty of Life Sciences, Hamburg, Germany.
Int J Comput Dent. 2008;11(3-4):169-74.
Individual bone quality depends on genetic, biological, and mechanical influencing factors, where the latter is accessible via Finite Element Simulation. This work is part of an interdisciplinary research project with the purpose of stepwise refinement towards anatomical reality. This approach opened the door for many interrelated applications such as atrophy of the jaw bone, periodontology, implantology, or TMJ disorders. This lecture is dedicated to the influence of dental anatomy on mandibular biomechanics.
In general, biomechanical simulation requires reconstruction of the individual anatomy, implementation of the inhomogeneous and anisotropic material law of bone, and realization of the load case due to tooth, muscle and joint forces. The simulation chain ranges from image processing of CT data up to specifically adapted post-processing of the simulation results. In spite of ongoing research, there is still a fundamental difference of dental implants compared to natural teeth: the periodontal ligament (PDL) present at the interface between teeth and mandibular corpus. Due to its thickness of about 0.2 mm, the PDL was introduced to the simulation model by a special semiautomatic procedure.
Simulations "with and without PDL" proved remarkable force absorption due to the PDL, as well as qualitative changes of the stress/strain profiles of the alveolar ridge. Concerning the simulation without PDL, the observed high compressive strains at the adjacent bone were in agreement with regions of frequent implant failure.
The PDL is essential for the structural behavior of the human mandible. Based on the mechanical adaptation of bone, the comparison of the simulation with and without PDL provided special insight to the changes due to dental implants, in particular implant loss and bone resorption. Finally, the simulation will serve as a virtual platform for further evaluation (a) of implant design (b) of implant placement.
个体骨质量取决于遗传、生物和机械影响因素，其中后者可通过有限元模拟获得。这项工作是一个跨学科研究项目的一部分，目的是逐步向解剖学现实细化。这种方法为许多相关应用打开了大门，如下颌骨萎缩、牙周病学、种植学或颞下颌关节紊乱。本次讲座致力于探讨牙齿解剖结构对下颌生物力学的影响。
一般来说，生物力学模拟需要重建个体解剖结构、实施骨的非均匀和各向异性材料定律以及实现由于牙齿、肌肉和关节力引起的载荷情况。模拟链从CT数据的图像处理一直到对模拟结果进行专门的后处理。尽管研究仍在进行，但与天然牙相比，牙种植体仍存在一个根本差异：牙齿与下颌骨体之间的界面处存在牙周韧带（PDL）。由于其厚度约为0.2毫米，通过一种特殊的半自动程序将PDL引入模拟模型。
“有和没有PDL”的模拟证明，由于PDL的存在，其具有显著的力吸收能力，以及牙槽嵴应力/应变分布的定性变化。关于没有PDL的模拟，在相邻骨处观察到的高压缩应变与种植体频繁失败的区域一致。
PDL对人类下颌骨的结构行为至关重要。基于骨的力学适应性，有和没有PDL的模拟比较为牙种植体引起的变化，特别是种植体丢失和骨吸收，提供了特殊的见解。最后，该模拟将作为一个虚拟平台，用于进一步评估（a）种植体设计（b）种植体植入位置。
