Abstract
Based on the results of the present study, it may be concluded that, a high expression of Ki-67 of Osteosarcomas in fluoridated area compared to those in non-fluoridated area explains the aggressive behavior of osteosarcoma and fluoride ions has a mitogenic effect on malignant osteoblasts. Ki-67 could be used as a diagnostic marker in patients with osteosarcoma and may provide a better histological grade which could affect the prognosis and survival rate