The goat as a model for temporomandibular joint disc replacement: Techniques for scaffold fixation

A state-of-the-art scaffold capable of efficiently reconstructing the temporomandibular joint (TMJ) disc after discectomy remains elusive. The major challenge has been to identify a degradable scaffold that remodels into TMJ disc-like tissue, and prevents increased joint pathology, among other significant complications. Tissue engineering research provides a foundation for promising approaches towards the creation of successful implants/scaffolds that aim to restore the disc. In light of improving the quality of life of patients who undergo TMJ disc removal, it is critical to establish a preclinical animal model to evaluate the properties of promising scaffolds implanted post-discectomy and to determine the most efficient implantation procedures to ensure a more reliable in-depth evaluation of the biomaterial replacing the articular disc. The present study evaluated the outcomes of two protocols for implantation of an acellular scaffold composed of an extracellular matrix (ECM) derived from the small intestinal submucosa (SIS) of the pig, as a regenerative template for the TMJ disc in a goat model. The outcomes suggest that leaving one-half of the disc medially will allow anchoring of the device to the medial aspect of the joint while avoiding lateral displacement of the ECM scaffold. The goat model is ideal to assess the longevity of tissue-engineered solutions for the TMJ disc, considering that goats chew for 12-16 hours a day. This study provides an important reference for the selection of a suitable scaffold implantation procedure and the goat model for the development of new strategies to assess TMJ disc regeneration.