Microscale Mechanics of Temporomandibular Joint Articular Cartilage

对下颌软骨的机械要求-被称为颞下颌关节或TMJ -特别苛刻。在咀嚼和研磨期间，该组织经历高水平压缩和滑动的重复负荷。 结果，这种软骨经常失败，正如美国4- 7%的人口经历TMJ疾病的事实所证明的那样。值得注意的是，该关节中软骨的结构与其他关节完全不同，并且该组织的结构如何与其机械功能相关尚不清楚。该项目的长期目标是了解TMJ关节软骨的机械特性如何与健康和疾病中组织的微观结构和组成相关。这些知识将增加对TMJ软骨如何在TMJ疾病患者中失败的理解。 本研究中开发的技术将纳入工程和生物学学生学习的实验室课程中，使他们能够将这种方法应用于各种组织和生物体。此外，PI将为研究生开发和实施科学交流课程和研讨会，并直接接触代表性不足的学生。 该项目将使用一种最先进的技术，能够以高水平的空间分辨率测量软骨的机械特性，同时将这些特性与组织的局部组成相关联。 成像技术包括共焦弹性成像、偏振测量和FTIR显微镜。 使用这种力学测试和成像方法的组合，该项目将表征TMJ力学特性的空间，功能和结构基础。这将包括基于表面位置、深度和正常加载情况下剪切力方向的压缩和剪切加载的线性和非线性特性。 机械性能将通过位置与胶原蛋白和聚集蛋白聚糖的局部浓度相关联。该项目的成功完成将为TMJ软骨力学的微观结构基础提供基础性的理解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The mechanical requirements for the cartilage that lines the jaw - known as the temporomandibular joint or TMJ - are particularly demanding. During chewing and grinding, this tissue experiences repetitive loading with high levels of compression and sliding. As a result, this cartilage fails quite frequently, as is evidenced by the fact that 4-7 percent of the population of the United States experiences TMJ disorders. Notably, the structure of the cartilage in this joint is quite different from other joints, and how the structure of this tissue relates to its mechanical function is not well understood. The long term goal of this project is to understand the how mechanical properties of the articular cartilage of the TMJ relate to the microstructure and composition of the tissue in both health and disease. Such knowledge will increase understanding of how the cartilage of the TMJ fails in individuals with TMJ disorders. The techniques developed in this research will be incorporated into laboratory courses taken by engineering and biology students, which will enable them to apply this approach to a wide variety of tissues and organisms. Additionally, the PIs will develop and implement courses and seminars on scientific communication for graduate students, with direct outreach to students from under-represented populations. This project will use a state-of-the-art technique that enables measurement of the mechanical properties of cartilage to a high level of spatial resolution while relating of these properties to the local composition of the tissue. Imaging techniques include confocal elastography, paloarimetry, and FTIR microscopy. Using this combination of mechanical testing and imaging methods, this project will characterize the spatial, functional, and structural basis of the mechanical properties of the TMJ. This will be include linear and non-linear properties for both compression and shear loading based on surface location, depth, and direction of shear force during normal loading scenarios. The mechanical properties will be correlated via location with local concentrations of collagen and aggrecan. Successful completion of this project will provide foundational understanding of the microstructural basis for the mechanics of cartilage from the TMJ.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.