Tooth loss and skeletal bone density in healthy postmenopausal women

Associations between dental status and skeletal bone density were investigated in a group of 329 healthy postmenopausal women with normal bone density. Bone mineral density (BMD) of the lumbar spine, femoral neck and distal radius were measured by dual- or single-photon absorptiometry. Number of teeth remaining were counted and presence of complete dentures noted by a nurse practitioner. Forty-eight women (15%) wore a complete maxillary and/or mandibular denture: 22(7%) were completely edentulous and an additional 26 (8%) had one edentulous ridge. Among women without complete dentures (n = 281), significant positive linear relationships were observed between number of teeth and BMD at the spine (p < 0.05) and radius (p < 0.01), controlling for years since menopause, pack-years of smoking, education and body mass index. BMD did not differ between the groups with and without dentures. However, women who acquired dentures after the age of 40 years had significantly lower mean spinal and radial BMD than women who acquired dentures at age 40 years or earlier (at the radius, 0.584 +/- 0.015 v 0.630 +/- 0.017 g/cm2, p < 0.05; at the spine, 1.043 +/- 0.031 v 1.124 +/- 0.029 g/cm2, p = 0.05). In linear regression analysis, significant independent correlations were found among all women (n = 329) between number of teeth and age (partial r = -0.19, p < 0.001), pack-years of cigarette use (partial r = -0.23, p < 0.001) and years of education (partial r = +0.11, p < 0.05). These associations between dental status and BMD support the hypothesis that systemic bone loss may contribute to tooth loss.