The literature supports the fact that estrogen plays an important role in skeletal maintenance and remodeling. Estrogen, acting through estrogen receptors in the cells of the periodontal ligament, has a regulatory interaction on bone dynamics through a complex set of basic multicellular units (BMUs). Deficiency of estrogen results in an increased number of BMUs and enhanced bone turnover. The impact of the changes in estrogen deficiency on bone dynamics is primarily mediated through osteoclasts, with greater interdiction of estrogen's actions on trabecular bone than on cortical bone. The purpose of this manuscript is to review the literature for evidence to support an association between estrogen and periodontal disease in adult women, as well as bone mineral density, and to help clarify the mechanism of action. We found in our review of all pertinent databases, including Cochrane, that there are few peer-reviewed clinical studies that examine the relationship between estrogen deficiency and periodontal disease, and bone mineral density (BMD) and periodontal disease. Thus, future research is needed to investigate these associations so that at-risk patients can be identified earlier to avoid functional and esthetic sequellae of periodontal disease.