The Residual Ridge Resorption (RRR) is a major unsolved oral disease with unidentifiable characteristics and unwanted squealae causing physical, psychologic, and economic problems for millions of people all over the world. RRR is basically a term used to describe a condition that affects the alveolar ridge after tooth extractions even after healing of the wounds. RRR is a chronic, progressive, irreversible, and disabling disease, probably of multifactorial origin. The possible etiological factors could be divided into four categories: anatomic, metabolic, functional, and prosthetic. The primary structural change in the reduction of residual ridges is the loss of bone or reduction in the size of bony ridge under mucoperiosteum. The reduction in the ridge mainly occurs labially, lingually and on the crest. The reduction of the residual ridge leads to a variety of stages of ridge form, including high well-rounded, knife-edge, low well-rounded, and depressed forms. Alveolar bone atrophy is cumulative and irreversible, since alveolar bone cannot regenerate. It differs from one individual to the other. It also varies at different times and different sites. Some authors feel RRR as a normal physiologic process and not a disease but the cost in economic and human terms makes RRR as a major oral disease that can be described in terms of its pathology, pathophysiology, pathogenesis, epidemiology, etiology, treatment and prevention.