Because atrophy of the jaws in edentulous patients is a major health problem, how best to reconstruct the atrophic mandible is a dilemma that frequently confronts the medical and dental professions. After loss of the natural dentition, the reduction of the residual ridges is progressive, irreversible, and cumulative. The cause and pathogenesis of mandibular atrophy is discussed. In the evaluation of a patient, the amount of residual bone at the symphysis should be measured on the lateral cephalometric radiograph as an aid to treatment planning. This measurement allows the degree of atrophy to be classified as minor, moderate, or severe. The current techniques to rehabilitate the edentulous mandible, including relative and absolute heightening techniques and implants, are reviewed with illustrative examples. A modification of a previous absolute heightening osteotomy technique utilizing pedicle bone flaps, is presented.