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.
