In latest year, the relationship between whole body osteoporosis and jawbone osteoporosis, and also the relationship between bone density from whole body and jawbone have been recognized. As Mg is related to the bone density of whole body and the weakness of alveolar bone, it deeply connects to the denture treatment and the convalescence after implant treatment. It related to avoid losing teeth during the suppression of acid solubility of enamel, too. For the importance to control the absorption of alveolar bone which can support the teeth, it is necessary to have more consideration on Mg in the relationship between whole body's bone and alveolar bone.