Abstract :This study is to investigate the changes of Temporomandibular Joint (TMJ) by experimentally induced osteoarthritis (OA) and to compare effectiveness of intraarticular injections. Intraarticular Monosodium Iodoacetate (MIA) solution was injected bilaterally to experimental groups to induce TMJ osteoarthritis. 0•9% NaCl solution was injected to TMJ of healthy control group bilaterally to investigate the effect of trauma by intraarticular injection. For treatment group were injected intraarticularly with Hyaluronic Acid (HA), second subgroup with Dexamethasone (DEX) and third subgroup with Botulinum Toxin A (BTX A). Groups treated with HA and DEX showed statistically significant healing compared with untreated MIA group.