Department of Construction and Manufacturing Engineering, University of Oviedo, Gijón, Spain.
Department of Construction and Manufacturing Engineering, University of Oviedo, Gijón, Spain.
J Biomech. 2019 Aug 27;93:126-131. doi: 10.1016/j.jbiomech.2019.06.023. Epub 2019 Jul 2.
In this study, shear relaxation properties of the porcine temporomandibular joint (TMJ) disc are investigated. Previous studies have shown that, in fatigue failure and damage of cartilage and fibrocartilage, shear loads could be one of the biggest contributors to the failure. The aim of the present study is to develop an evaluation method to study shear properties of the disc and to do a mathematical characterization of it. For the experiments, twelve porcine discs were used. Each disc was dissected from the TMJ and, then, static strain control tests were carried out to obtain the shear relaxation modulus for the central region of the discs. From the results, it was found that the disc presents a viscoelastic behavior under shear loads. Relaxation modulus decreased with time. Shear relaxation was 10% of the instantaneous stress, which implies that the viscous properties of the disc cannot be neglected. The present results lead to a better understanding of the discs mechanical behavior under realistic TMJ working conditions.
本研究旨在探讨猪颞下颌关节（TMJ）盘的剪切松弛特性。先前的研究表明，在软骨和纤维软骨的疲劳失效和损伤中，剪切载荷可能是导致失效的最大因素之一。本研究的目的是开发一种评估方法来研究盘片的剪切特性，并对其进行数学表征。在实验中，使用了 12 个猪盘。每个盘从 TMJ 中分离出来，然后进行静态应变控制测试，以获得盘中央区域的剪切松弛模量。结果表明，盘在剪切载荷下表现出粘弹性行为。松弛模量随时间减小。剪切松弛为瞬时应力的 10%，这意味着盘的粘性特性不能被忽略。本研究结果有助于更好地了解 TMJ 实际工作条件下盘的力学行为。
