The National Institute of Dental and Craniofacial Research (NIDCR) recognizes the significance of TMJ disorders and leads the Federal research initiative to develop clinically superior treatment options for those suffering with severe TMD. In severe cases of damage or internal derangement (ID) the disc is surgically removed, unfortunately current alloplastic disc replacements such as Proplast-Teflon and Silastic implants are prone to fragmentation and tearing, leading to complications such as bone resorption and osteoarthritis. In response to these shortcomings, a variety of alternative approach's for restoring the function and movement capabilities of the TMJ have been assessed. A great deal of promise has been shown with the application of tissue engineering principles to replace damaged or diseased tissues with regenerated, 'living'tissues. With this methodology no additional damage to the surrounding anatomy of the joint would be experienced, and the newly implanted re-engineered disc would ideally accommodate typical loads of the joint and regain physiologically functionality. In this proposal we utilize a native porcine TMJ disc as a xenogenic ex vivo scaffold, and further modified the discs structure to enhance reseeding and transport conditions to improve both mechanical and biological function. Our preliminary data has shown the utility of the approach with decellularized scaffolds maintaining mechanical properties similar to native discs. Our goal is to further develop a physiologically compatible xenogenic acellular temporomandibular articular disc scaffold with modified microporosity using a high precision laser ablation technique to overcome transport and cell migration deficiencies. Our longer-term goal is to use this scaffold either as a direct acellular implant or as a regenerated disc (human cells) as a total disc replacement strategy for those suffering with severe TMD or ID. To accomplish this goal we propose the following specific aims:
Specific aims. Specific Aim 1: Characterize a naturally derived temporomandibular disc scaffold which maintains native extracellular matrix characteristics and has parameters that allow for precise laser interactions.
Specific Aim 2 : Design a high precision laser ablation paradigm that optimizes artificial porosity geometry for transport capability while minimizing mechanical degradation due to volume loss and microenvironment disruption. Then to evaluate seeding methodology and culture conditions for cell ingrowth, cell metabolism, and gene expression to assess fibrochondocyte cell function in relation to structural changes to the scaffold.
Specific Aim 3 : Test the hypothesis that physiologic mechanical stimulation encourages fibrochondrocytes to remodel the pTMJ scaffold toward its native mechanical properties, and that the engineered disc can be used to simulate disease conditions for further evaluation. We hypothesize that by improving transport conditions and enhancing cell seeding and nutrient delivery using a high precision laser ablation technique that significant improvements in both mechanical and biological function will be attained. These advances may lead to improved treatment options for patients suffering with irreparably damaged Temporomandibular Joint (TMJ) discs.
It is estimated by the Food and Drug Administration that 25 percent of the United States of America populous suffer from a Temporomandibular Disorder (TMD) and about 70 percent of those people are afflicted by disease, damage, or deformity of the TMJ disc. In severe cases of damage or internal derangement (ID) the disc is surgically removed, unfortunately current treatments are far from sufficient. In response to these shortcomings we will develop a physiologically compatible xenogenic acellular temporomandibular articular disc scaffold with modified microporosity using a high precision laser ablation technique to overcome transport and cell migration deficiencies effectively enhancing tissue regeneration for use as a total disc replacement strategy for those suffering with severe TMD or ID.
|Juran, C M; Dolwick, M F; McFetridge, P S (2013) Shear mechanics of the TMJ disc: relationship to common clinical observations. J Dent Res 92:193-8|