Prevention of adhesions in the temporomandibular joint by the use of chitosan membrane in goats.

We evaluated the effects of chitosan membrane, a highly absorbable and viscous material, in the prevention of intra-articular adhesions after anchoring of the disc in the temporomandibular joints (TMJ) of six adult goats (12 joints). To simulate anterior displacement of the disc and TMJ trauma, we cut off the retrodiscal attachment and damaged the surface of the condylar bone, then randomly divided the goats into two groups: the control group (n=2) and the experimental group (n=4). In the experimental group we covered the condylar surfaces on both sides of the animals with chitosan membranes. Those in the control group had operations and no special treatment. We took magnetic resonance images (MRI) of all the animals before the operation and at three and six months postoperatively, and measured the interincisal opening and strength at the same time. We counted the number of adhesions macroscopically, and evaluated the adhesive tissues, cartilage, and subchondral bony changes histologically and immunohistochemically. Measurements of the interincisal opening and strength were significantly better in the experimental group than in the controls (p<0.05). Macroscopic evaluation (using a specific adhesion scoring system) showed a significant difference in the formation of adhesions between the groups (p<0.05). Although MRI showed no significant difference between the groups, the histological and immunohistochemical observations supported the hypothesis that chitosan membrane could prevent intra-articular adhesions. It seems to inhibit the formation of adhesions effectively and promote repair of the cartilage. It may therefore be considered a promising absorbable biomaterial to prevent adhesions after operations on the TMJ.