Effect of bone mineral density in skeleton and mandible on extraction of teeth and clinical alveolar height.

Residual ridge resorption of the maxillae and mandible after tooth extraction adversely affects many edentulous people. The jaws of 355 postmenopausal women were examined clinically, and the number of teeth and the clinical height of alveolar ridges in edentulous jaws were determined. Each subject was asked when the last teeth had been extracted. To study the bone mineral status of each woman, the bone mineral densities of the femoral neck and the lumbar spine were measured by dual-energy x-ray absorptiometry. For 77 edentulous or almost edentulous women, the bone mineral density of the mandibular cortex and the spongiosa were measured by quantitative computed tomography. The results were studied to determine whether the general status of osteoporosis or the local bone mineral densities in the mandible affect the time of extraction of teeth or the remaining height of edentulous alveolar ridges. Neither the time when the teeth were lost nor the number of teeth was dependent on the general bone loss, but in some regions, the clinical height was affected.