Experimental Study on In Situ Tissue Engineering of the Temporomandibular Joint Disc using Autologous Bone Marrow and Collagen Sponge Scaffold

The temporomandibular joint (TMJ) disc plays an important role in mandibular motion. Once the TMJ disc perforates, spontaneous recovery does not occur. The aim of this study was to induce regeneration of the TMJ disc through an in situ tissue engineering method. Japanese white rabbits weighing 2.5-3.0 kg were used in this study. The TMJ was surgically exposed and a round full-thickness perforation of diameter 1.6 mm was made in the center of the disc. Animals were divided into A and B groups. In group A, a collagen sponge scaffold (1.6 mm in diameter with a height of 1.0 mm) was placed in the perforation. In group B, a collagen sponge scaffold mixed with autologous bone marrow was placed in the perforation. In both groups, a control perforation was made on the opposite side and left unfilled. The TMJ discs with surrounding tissues were collected 2, 4 and 8 weeks after surgery and were subjected to histological evaluation. In group A, after 4 weeks the size of perforation was reduced, but after 8 weeks, the perforation had still not completely closed. In group B, after 2 weeks, regeneration of the disc was seen and the site of the perforation was completely filled by new connective tissue. In the controls, after 8 weeks, the size of perforation was reduced, but it had not completely closed. The results indicate that collagen sponge scaffold with autologous bone marrow may have the potential to induce regeneration of a damaged TMJ disc.