Osteoporosis: a review and its dental implications.

Osteoporosis is a disease that affects primarily women, but can also occur in men. It is characterized by a loss of bone mineral density (BMD), and often culminates in a fracture of the hip, wrist, and/or vertebrae. The diagnosis of osteoporosis is often made by using bone density measurements. They are often expressed in relative terms (T-scores and Z-scores); the Z-score is the number of standard deviations from the age-matched average value of healthy women. A low Z-score indicates the bone density is lower than it should be for a patient's age and sex. Osteoporosis is defined as a BMD loss of 2.5 standard deviations or more below the established mean. Osteoporosis can be treated by a variety of methods, the most common being the use of estrogen, with or without progestin or progesterone. The use of estrogen alone is referred to as estrogen replacement therapy (ERT), and the combination hormone replacement therapy (HRT). Other drugs used in the treatment of osteoporosis are the selective estrogen receptor modulators (SERMs) and the bisphosphonates. The SERMs appear to offer many of the positive benefits of estrogen with fewer adverse effects on the breast or uterus. Recently, a randomized, double blind study of nearly 3,000 women found no overall benefit in reducing heart disease for those taking estrogen. In fact, in the first year of estrogen use, heart disease was higher in this group than in those taking placebo. The relationship between systemic BMD and periodontal status has been investigated. In some patients, there is a correlation between a decrease of mandibular bone mass and tooth loss. In others, there is no such correlation. Those postmenopausal women taking HRT had greater tooth retention and a reduced likelihood of edentulism. A recent study has found no correlation between clinical attachment levels and the BMD of the lumbar spine. Many possible factors contribute to the development of osteoporosis and periodontal diseases. It is difficult to establish a direct correlation between tooth loss, bone loss, and loss of attachment resulting from periodontitis and decreased BMD associated with osteoporosis, but studies are ongoing.