Project Summary/Abstract As many as 10 million adults in the United States have temporomandibular disorders (TMDs). Females experience TMDs at higher rates compared to males and African Americans have higher TMD incidence, yet lower prevalence compared to white Americans. Despite these findings, etiological mechanisms contributing to prevalence and incidence disparities by sex and race are largely unknown. Given our recent reports on sexual dimorphisms in incremental tensile stiffness and fixed charge density of the human temporomandibular disc, it is hypothesized that additional sexual dimorphisms may exist in properties of the temporomandibular joint (TMJ). Similar differences are also hypothesized to exist between racial groups, although this possibility has not yet been explored, which may limit research translational confidence across racial groups. The lateral capsule- ligament (LCL) complex, which spans the temporal bone and mandibular condyle, could impact temporomandibular disc derangement (TMDD) risk through a ‘loose ligament’ mechanism affecting joint articulation postulated in prior literature. Furthermore, sex- and race-specific differences in potential risk and resiliency factors may contribute to differential risk of TMDD development and observed TMD prevalence and incidence disparities. Our long-term goal is to enable individualized TMDD risk assessment to increase applicability of generated risk estimates. The objective of this study is to describe sex- and race-specific mechano-chemical LCL complex properties to investigate potential contributions to TMD disparities between sexes and racial groups. The central hypothesis is that TMJ properties observed in females and African Americans will be associated with higher risk of TMDD development compared to those of males and white Americans. The proposed studies will enable the determination of sex- and race-specific differences in potential mechanical and chemical risk factors for TMD development (Aims 1 and 2). This determination will contribute to a better understanding of TMJ properties across diverse populations and is crucial to enabling understanding of TMD incidence and prevalence disparities. Finite element models will also be used to investigate how differences between sexes and racial groups impact the temporomandibular loading environment, which will be developed, refined, and interpreted during the independent phase (Aim 3). This proposal aims to further development of scientific expertise and skill acquisition in temporomandibular and craniofacial biomechanics, with a plan to transition from mentored post-doctoral fellowship to independent faculty. NIH T32 training and professional development resources, joint resources and network of the Clemson- MUSC Bioengineering program, and the Clemson University Pathways Mentoring Program provide an ideal inter-disciplinary training environment to prepare for and transition to independence following the postdoctoral fellowship p...