EFFECT OF EXPERIMENTAL TRAUMATIC OCCLUSION ON BLOOD-FLOW IN THE TEMPOROMANDIBULAR-JOINT OF THE RAT

Fluorescent microspheres (FM) were used to visualize and semi-quantify blood flow in the temporomandibular joint (TMJ) during experimental u nilateral traumatic occlusion of the maxillary and mandibular molar te eth in 30 young rats. At different postoperative observation periods v arying from 1 to 30 days FM were injected systemically, and the number of FM were counted in serial sections from the TMJ in a fluorescent m icroscope. Blood flow was related to the number of FM found in the fib rous connective tissue and bony condyle of the TMJ. A percentage incre ase in blood flow was found at 15 to 20 days on the experimental side, compared with the contralateral side. Furthermore, there was an incre ase in blood flow in both TMJs in the experimental animals compared wi th an unoperated control material of 10 animals. The study thus indica tes that a local unilateral occlusal trauma initiates blood flow respo nses not only unilaterally but also in the TMJ on both sides in rats.