Mandibular atrophy and metabolic bone loss. Histomorphometry of iliac crest biopsies in 74 patients.

Histomorphometry of iliac crest biopsies of 74 edentulous patients with severe atrophy of the mandible submitted for ridge augmentation, showed a minority of the patients (14%) to have a significant decrease of trabecular bone volume, indicating osteoporosis. On the other hand, osteoid volume, osteoid seam thickness and active resorption surface, parameters for disturbances in mineralization, lack of calcium and hyperfunction of parathyroid glands, were significantly increased by 38%, 88% and 65% of the patients, respectively. These findings were more pronounced in the patients with radiological evidence of metabolic bone loss (38%, Gonion less than 1). It may be concluded that metabolic bone loss, due to a lack of calcium and a subsequent hyperfunction of the parathyroid glands, plays a role in the etiology of severe atrophy of the edentulous mandible. which therefore might be prevented by supplementing with calcium with or without vitamin D.