Bone is remodeled and modeled by the concerted activities of 3 cell types—osteoblasts, osteocytes, and osteoclasts. Osteoblasts are the cells that produce bone extracellular matrix and are responsible for its mineralization.Osteoblasts also have endocrine activity through secretion of osteocalcin, which regulates fat and energy metabolism. These cells also control the differentiation and activity of osteoclasts.Osteocytes are osteoblasts that have been incorporated into bone matrix and are cells with extensive dendritic processes through which the cells communicate with other osteocytes and with osteoblasts.n parallel, osteoblasts degrade the unmineralized bone matrix, which is present between the cells and the mineralized bone, and then retract from the area giving the latent osteoclasts a possibility to migrate into the area and attach to mineralized bone through the sealing zone.