To create an animal model of anterior disc displacement of temporomandibular joint (TMJ) for studying the pathologic change of anterior disc displacement.
The disc was surgically displaced anteriorly in the right temporomandibular joint in each of 25 rabbits. The outer capsular of anterior attachment of disc was exposed through the floor of the orbit and the temporal extension of the anterior band of disc was sutured to the zygomatic arch. The left side was approached in a similar manner except for repositioning the disc anteriorly. Five additional rabbits served as non-surgical controls. The animals were sacrificed at 1, 2, 4, 8, and 12 weeks after surgery. The histological changes were observed.
Microscopic observation showed 11 joints with partial anterior disc displacement, 8 joints with complete anterior disc displacement, and 6 joints with perforation of disc in the surgical groups. The histological changes included physiologic remodeling or early degenerative changes in the partial anterior disc displacement joints, degenerative changes in the complete disc displacement joints, and severe osteoarthritic changes in the perforated joints.
The degree of anterior disc displacement caused different kinds of osteoarthritic changes in the articular cartilage of the experimental animals.