Ramos A, Mesnard M, Relvas C, Completo A, Simões J A
Department of Mechanical Engineering, University of Aveiro, Portugal.
Univ. de Bordeaux, Institut de Mécanique et d'Ingénierie, CNRS UMR 5295, Talence, France.
J Craniomaxillofac Surg. 2014 Mar;42(2):169-74. doi: 10.1016/j.jcms.2013.04.007. Epub 2013 May 17.
Virtual design gives flexibility to explore constructive solutions or structures. It enables analysis that would often be impossible even if expensive real prototypes were available. Simulations using finite element models allow access to the stress and strain tensor or to the deformation tensor within an implant or a tissue which is impossible experimentally, even in vitro. This study is based on two numerical models of temporomandibular joint (TMJ) implants, comparing two bone-implant connections: an external connection performed with surgical screws (commercial model) and an internal connection carried out by penetration into the intramedullary space. The finite element models were constructed based on a cadaveric mandible and considering the five principal muscles in action. Strain distributions into the surrounding bone tissue are analysed and in both models they show significant differences at the external surface of the mandible in displacements. However, while the intramedullary fixation increases strains in the cancellous tissue, the study shows that strain distribution is mainly influenced by the number and distribution of screws in commercial solution.
虚拟设计为探索建设性解决方案或结构提供了灵活性。它能进行一些即使有昂贵的真实原型也往往无法开展的分析。使用有限元模型进行的模拟能够获取植入物或组织内部的应力张量、应变张量或变形张量，这在实验中甚至在体外都是不可能实现的。本研究基于颞下颌关节（TMJ）植入物的两个数值模型，比较了两种骨 - 植入物连接方式：一种是用外科螺钉进行的外部连接（商业模型），另一种是通过穿透进入髓腔空间进行的内部连接。有限元模型是基于一具尸体下颌骨构建的，并考虑了起作用的五块主要肌肉。分析了周围骨组织中的应变分布，在两个模型中，它们在下颌骨外表面的位移上都显示出显著差异。然而，虽然髓内固定会增加松质组织中的应变，但研究表明，应变分布主要受商业解决方案中螺钉数量和分布的影响。
