Q. Consequences on the bony structures?
Basal bone forms the dental skeletal structure. Wolff's law states that the bone remodels in relationship to the forces applied. With a change in the function of the bone everytime, a definite change occurs in the internal architecture and external configuration. When a tooth is lost, the lack of stimulation to the residual bone causes a decrease in trabeculae and bone density in the area, with loss in the external width, then height, and then of the bone volume. This issue, of utmost importance, has been ignored in the past by traditional dentistry. The patient is often not educated about the anatomic changes and the potential consequences of continued bone loss. The bone loss often accelerates on wearing a poorly fitting soft tissue-borne prosthesis. The continued atrophy of the posterior mandible eventually causes prominent mylohyoid and internal oblique ridges covered by thin, movable, unattached mucosa, prominent superior genial tubercles with the resulting elevation of prosthesis with contraction of mylohyoid and buccinator muscles serving as a posterior support. In a partially edentulous patient wearing a removable soft tissue-borne prosthesis, the natural abutment teeth, on which direct and indirect retainers are designed, are submitted to additional lateral forces. In addition, these teeth being often compromised by deficient periodontal support, many partial dentures are designed to minimize the forces applied to them. The result is an increase in mobility of the removable prosthesis and greater soft tissue support. These conditions protect the remaining teeth, but accelerate the bone loss in the edentulous regions. Thus implants have come out as an answer to these problems.