Osteoclast is a type of bone cell that eliminates bone tissue by destroying the bone matrix. This process is called bone resorption. Osteoclast is a multinucleated phagocytic cell of monocyte or monocyte-like cell origin. In normal bone tissue, osteoblasts and osteoclasts are in balance. They are large cells with a size of 150 microns. destroys bone tissue. It is a member of the mononuclear phagocytic system. During bone formation, they settle on the surface of the trabeculae or on the inner surfaces of the compact parts and dissolve them. During destruction, they settle in the cavities called Hawship lacunae, which are opened by enzymatic activity. Osteoclasts are generally more in the regions where the bone is reshaped. Osteoclast effect is under the influence of parathyroid and calcitonin. Calcitonin decreases while parathyroid increases activity.