Matrix metalloproteinase and tissue inhibitor of metalloproteinase in serum and lavage synovial fluid of patients with temporomandibular joint disorders

We measured matrix metalloproteinases (MMPs) and tissue inhibitor of metall oproteinases (TIMP) in temporomandibular joint (TMJ) disorders, All patient s were fully investigated, by visual analogue pain scores, plain radiograph s and double-contrast arthrotomograms. The patients were grouped according to whether or not they were in pain. There were 35 patients with painful jo ints; 16 painless crepitating joints and 10 with chronic closed locked join ts. A further group of 9 volunteers with no symptoms of TMJ abnormalities w ere used as controls. We found that synovial fluid concentration of MMP-3 was significantly incre ased (1117.2 (164.0) ng/ml) (P < 0.05) in the painful group compared with c ontrols (436.2 (94.8) ng/ml) and with the two groups with painless TMJ (475 .0 (113.0) ng/ml/crepitation, and 516.0 (115.1) ng/ml/closed locked joints) , MIMP-1 and TIMP-1 were not recordable in most joints, and the serum conce ntrations of MMP-1, MMP-3, and TIMP-1 were similar to those in controls in all groups. There was no correlationship between MMP-3 concentration and jo int morphology as shown by plain radiographs and double contrast arthrotomo grams, These findings indicate that the synovia of painful joints are infla med.