Estrogen replacement therapy--something to smile about.

Tooth loss and alveolar residual ridge resorption are significant oral health problems in older adults. Although the causes of tooth loss are many, several studies show an association between tooth loss/residual resorption and systemic osteoporosis. Because estrogen replacement therapy (ERT) slows the development of osteoporosis, we investigated the relationship between estrogen use and tooth loss among elderly women who were participating in the Leisure World Cohort Study. Among 3,921 women 52 to 109 years old (median = 81), those who had ever used estrogen retained more teeth than nonusers (21.2 vs 19.2). The age-adjusted risk of having fewer than 25 teeth decreased with increasing duration of ERT: 0.87 for < 4 years of ERT, 0.74 for 4 to 14 years, and 0.70 for 15+ years compared to nonusers. Similarly, the risk of edentia was inversely related to estrogen use. If a woman had ever taken ERT, her risk of losing all her teeth was about two thirds that of a woman who had never used estrogen. Long-term users (15+ years) had half the risk of becoming toothless. Despite differences in age, education, methods of obtaining tooth and hormone data, and prevalence of tooth loss, two other cohort studies (the Nurses' Health Study and the Framingham Heart Study) reported similar reductions in tooth loss among estrogen users. The data suggest that tooth retention, in addition to being affected by osteoporosis of alveolar bone, also shares in the benefits of ERT on osteoporosis.