The use of a collagen sheet as a disc replacement in the rabbit temporomandibular joint.

Objective: This study evaluated a biocompatible, preformed collagen sheet as a disc replacement after temporomandibular joint (TMJ) surgery in the rabbit and compared its performance with that of an autogenous dermal graft.

Methods: Twenty adult New Zealand white rabbits were divided into four groups of five animals: 1) nonoperated control; 2) TMJ discectomy without replacement; 3) discectomy with dermal graft replacement; and 4) discectomy with collagen sheet replacement. Each operated animal had the same procedure bilaterally. Rabbits were killed at 2, 4, 8, 18, and 36 weeks after surgery and the TMJs were surgically removed en bloc, decalcified, sectioned, and stained for histologic evaluation.

Results: There was significant articular destruction in the discectomized joints with no disc replacement. Both the dermal and collagen disc replacements were resorbed by the eighth week and the articular surfaces exhibited cartilaginous hyperplasia, which returned to near normal thickness by the 18th week.

Conclusions: This study demonstrated that both a collagen sheet and a dermal graft may act in a protective capacity and may help retard early degenerative changes normally seen in the articular surfaces of discectomized TMJs.