Relationship between dental panoramic radiographic findings and biochemical markers of bone turnover

Introduction: Recent studies suggest that mandibular inferior cortical shape and width on dental panoramic radiographs may be useful screening tools for low skeletal bone mineral density (BMD) or increased risk of osteoporotic fracture. However, little is known as to whether these measures are associated with bone turnover. We investigated relationships among dental panoramic radiographic findings, spine BMD, and biochemical markers of bone turnover in postmenopausal women. Materials and Methods: Of 609 women who visited our clinic for BMD assessment between 1996 and 2002, 82 Japanese postmenopausal women, 46-68 years of age (54.1 +/- 4.9 years), were recruited for this study. Mandibular interior cortical shape (normal, mild/moderate erosion, severe erosion) and width were evaluated on dental panoramic radiographs. BMD at the lumbar spine (L2-L4) was measured by DXA and categorized as normal (T-score > -1.0), osteopenia (T-score, -1.0 to -2.5), or osteoporosis (T-score < -2.5). Bone turnover was estimated by serum total alkaline phosphatase (ALP) and urinary N-telopeptide cross-links of type I collagen (NTx), corrected for creatinine. Results: The odds of low spine BMD in subjects with any cortical erosion were 3.8 (95% Cl, 1.2-12.5). Mandibular cortical erosion was significantly associated with increased NTx (p < 0.001) and ALP (p < 0.05) levels. The associations of spine BMD with NTx and ALP were similar. Mandibular cortical width was significantly associated with spine BMD but not with NTx and ALP levels. Conclusions: Our results suggest that mandibular inferior cortical shape on dental panoramic radiographs may be an indicator of bone turnover and spine BMD in postmenopausal women. Dentists may be able to identify postmenopausal women with increased risk of osteopenia and osteoporosis on routine dental panoramic radiographs.