Microscale Mechanics of Temporomandibular Joint Articular Cartilage

下颌软骨的力学要求尤其苛刻，这种软骨被称为颞下颌关节。在咀嚼和研磨过程中，这种组织经历了重复加载和高水平的压缩和滑动。因此，这种软骨经常发生故障，美国4%-7%的人口患有TMJ障碍就是明证。值得注意的是，这个关节的软骨结构与其他关节有很大的不同，这种组织的结构与其机械功能的关系还没有被很好地了解。这个项目的长期目标是了解TMJ关节软骨的机械性能如何与健康和疾病中组织的微观结构和组成有关。这些知识将增加对患有TMJ障碍的人TMJ软骨如何衰竭的理解。这项研究中开发的技术将被纳入工程和生物专业学生的实验室课程，这将使他们能够将这种方法应用于各种组织和生物体。此外，PIS将为研究生开发和实施关于科学交流的课程和研讨会，并直接接触来自代表性不足人群的学生。该项目将使用一种最先进的技术，使测量软骨的机械特性达到高水平的空间分辨率，同时将这些特性与组织的局部组成联系起来。成像技术包括共聚焦弹性成像、掌纹测量和FTIR显微镜。利用机械测试和成像方法的组合，该项目将表征TMJ机械性能的空间、功能和结构基础。这将包括基于正常加载方案中的表面位置、深度和剪切力方向的压缩和剪切加载的线性和非线性属性。机械性能将通过定位与胶原蛋白和聚集素的局部浓度相关联。该项目的成功完成将为TMJ提供对软骨力学微观结构基础的基础性理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.