The influence of high molecular weighted hyaluronic acid (Hylan G-F 20) in use of temporomandibular internal derangement and osteoarthritis on apoptosis

The efficacy of synovial apoptosis on the degenerative bone changes and the role of intraarticular hyaluronic acid injection is not known in patients with internal derangement and OA. Although it has been suggested that the increased apoptosis in synovium could effect on joint degeneration, the relation between apoptosis and hyaluronic acid, which has a direct effect on chondrocytes is not explained and the purpose of this study is to determine whether there is a relationship between them. The levels of sFas , CD44, NMP, TLR 2 and TLR 4 in synovial fluid taken from joints with internal derangement and OA by using arthrocentesis and intraarticular injection are determined. Thirty five joints from 34 patients with pain, joint sounds, limitations in mouth opening, disc displacement on MRI which were not respondant to conservative treatment were included. Maximum mouth opening, supported maximum mouth opening, amount of lateral and protrusive movements, joint sounds, disc and condyle relations on T1 and T2 weighted MRI, degenerative changes, erosion, osteophyte and effusion were recorded. Pain was evaluated by VAS score. The sandwich ELISA method were used in order to evaluate the levels of human APO-1/Fas/CD95, NMP, TLR 4, TLR 2, CD44. MMO increased from 27,94±5,20 mm to 29,82±5,94 mm. There was a statistically significant increase in the right and left lateral and protrusive movements (p<0.01), and there were significant decreases in mean VAS scores (4,62±2,98 to 3,11±2,91 and 7,45±2,06 to 5,85±2,77 respectively) (p=0.001). Although the decreases in mean sFas and CD44 levels were statistically significant before and after treatment (p=0,013 and p=0,009), no statistical significance was found between NMP, TLR 2 and TLR 4 levels (p>0,05). While a positive relation was found between sFas and TLR 4 and between NMP and TLR 4 levels (p<0,01 and p<0.05), where as negative relation was found between sFAS and TLR4 (p<0,05). There was no statistically significant relationship between TLR4 and TLR2 values (p>0,05). The decreased mean levels of sFas and CD44 in joints with OA were statistically significant (p=0,047 and p=0,028), where as NMP, TLR 2 and TLR 4 levals were not significant (p>0,05). The levels of CD44 and NMP in joints with effusion before treatment were found to be statistically high and significant than the joints without effusion (p=0,003 and p=0,007, respectively). NMP values in joint without effusion were statistically high and significant (p=0,016).It is concluded that high molecular weighted hyaluronic acid (Hylan G-F 20) injection after arthrocenthesis induces apoptosis in TMJ, by generally affecting inflammatory cells. Key Words: Temporomandibular Joint, apoptosis, sFas, CD44, NMP, TLR, osteoarthritis, Hylan G-F 20.