The skeleton is a highly specialized and dynamic organ that undergoes continuous regeneration. Its functions are to maintain the shape of the body, protect vital organs, serve as a scaffold for the muscles, allowing their contractions to be translated into bodily movements, resist mechanical load during locomotion and weight bearing, and provide a reservoir of calcium, magnesium, bicarbonate, and phosphate. The skeleton consists of highly specialized cells, mineralized and unmineralized connective tissue matrix, and spaces that include the bone marrow cavity, vascular canals, canaliculi, and lacunae. During development and growth, the skeleton is sculpted in order to achieve its shape and size by the removal of bone from one site and deposition at a different one; this process is called modeling. Once the skeleton has reached maturity, regeneration continues in the form of a periodic replacement of old bone with new at the same location (1). This process is called remodeling. Removal of bone is the task of osteoclasts. The cells responsible for new bone formation are osteoblasts.