RESUMO
OBJECTIVE: Mandibular indices, measured on panoramic radiographs, may be useful screening implements for low skeletal bone mass density (BMD). Recent studies suggest that radiographic examination of mandible may constitute an effective process for the early diagnosis of osteoporosis. Biochemical markers of bone turnover may be of value for prediction of individual bone loss and they may help in predicting risk of fracture in elderly women. In contrast to the vast information available on dental radiographic findings and BMD only scarce data exist on the relationship between panoramic mandibular indices and biochemical markers. The aim of this study was to examine the diagnostic performance of dental panoramic radiography and biochemical markers of bone turnover in relation to BMD at the spine in a group of postmenopausal women. SUBJECTS AND METHODS: An assessment of the number of lost teeth, mandibular cortical width (MCW) at the mental region and morphologic classification of mandibular inferior cortex (MIC grade) was performed on dental panoramic radiographs in a group of 141 postmenopausal women 38-81 years of age. BMD at the lumbar spine was measured by dual energy X-ray absorptiometry. BMD values were categorized as normal (T-score greater than 1.0), and as indicative of osteopenia (T-score -1.0 to -2.5) or osteoporosis (T-score less than -2.5) according to the World Health Organization classification. Serum bone alkaline phosphatase (BAP) was measured with an enzyme immunoassay. Cross-linked N-telopeptides of type I collagen (NTx) corrected for creatinine secretion, was measured with a competitive-inhibition enzyme-linked immunosorbent assay ELISA. RESULTS: In our study, a decrease in MCW by 1mm increases the likelihood of osteopenia or osteoporosis to 47% (p-value<0.05), having taken into consideration the effect of the years elapsed since menopause. The increase of alkaline phosphatase (ALP) per unit increase the likelihood of osteopenia or osteoporosis to 14% (p-value<0.05), having checked the effect of the years since menopause. A decrease in MCW by 1mm increases the likelihood of moderately or severely eroded cortex to 97% (p-value<0.001). The increase in ALP per 1 unit increases the likelihood of moderate or severe erosion per 10% (p-value<0.05), taking into account the years since menopause. CONCLUSIONS: Our results suggest that dentists have sufficient clinical and radiographic information that enables them to play a significant role in early diagnosis of osteoporosis in postmenopausal women. Panoramic radiographs and biochemical markers of bone turnover may be of value for prediction of individual bone loss and they may help in predicting risk of fracture in elderly women.
