Elderly women with oral exostoses had higher bone mineral density.

We examined the relationship between two opposite phenomena in elderly bone, bone loss (osteoporosis) and excessive bone formation (oral exostosis). We recruited, randomly, 44 female subjects without any conditions known to affect bone metabolism. The subjects were examined for exostosis, and bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. The Z score of the BMD was calculated; this is the deviation from the weight-adjusted average BMD of each age. Subjects with palatal tori ( n = 15) had a higher femoral BMD than controls ( n = 14) (0.580 +/- 0.213 vs -0.271 +/- 0.182; P = 0.0054). The subjects with palatal tori ( n = 12) also had a higher BMD than controls ( n = 12) at the radius (0.417 +/- 0.235 vs -0.533 +/- 0.294; P = 0.0194). In addition, subjects with mandibular tori ( n = 13) had a higher femoral BMD than controls ( n = 14) (0.569 +/- 0.242 vs -0.271 +/- 0.182; P = 0.0097). These results suggest that some common mechanisms are involved in the elevation of skeletal BMD and the occurrence of oral exostoses.