FRAX and mandibular sparse trabeculation as fracture predictors: a longitudinal study from 1980 to 2002

The fracture assessment tool (FRAX) is widely used for predicting fractures, but better methods are needed. The aim of this study was to determine whether visual assessments of mandibular trabecular bone could improve FRAX predictions. Three age-cohorts of women were examined twice - 499 women in 1980/1981 and 412 women in 1992/1993; 397 participated in both examinations. Information on 10-yr fracture events was available, and bone trabeculation was assessed in radiographs as 'dense', 'mixed', or 'sparse'. Fracture assessment tool values, without bone mineral density (BMD), were calculated twice. Both sparse trabeculation and FRAX >15% were associated with a twofold higher risk for future fracture in the younger group and with a three- to fourfold higher risk for future fracture in the older group. For those with both FRAX >15% and sparse trabeculation, the relative risk (RR) for a fracture in the next 10 yr was 5.9 (95% CI: 3.5-9.8) in the younger group and 22.7 (95% CI: 5.6-92) in the older group. If either FRAX >15% or sparse trabeculation was present, the RR was 2.6 (95% CI: 1.7-4.1) in the younger group and 15.7 (95% CI: 3.9-6.4) in the older group. We concluded that FRAX >15%, without BMD measurements, was an effective fracture predictor, and mandibular sparse trabeculation had a substantial additive effect. Together, FRAX plus mandibular sparse trabeculation predicts major osteoporotic fractures to approximately the same extent as does FRAX with BMD measurements.