Accuracy and precision of a densitometric tool for jaw bone

To develop a digital densitometric tool for jaw bone to analyse intraoral radiographs. To assess precision and accuracy for this tool and determine the minimal detection threshold for density changes.

Bone samples deriving from the premolar region of 47 human mandibles were selected for analysis. The samples were obtained from adult cadavers in the department of anatomy (Faculty of Medicine, KULeuven) with ethical approval. Digital radiography was performed on all bone samples. Direct volumetric measurements served as gold standard density values and allowed determination of accuracy. Dual-energy X-ray absorptiometry (DXA) scans were performed on all specimens. For all radiographs, density in mm Al eq was calculated using custom-made software, Osteop. Precision and intraobserver and interobserver reliability of this method were assessed. The bone specimens were progressively decalcified. At standard time intervals the percentage of decalcification was calculated. At each decalcification step, radiographs were taken and analysed.

CV was always lower than 3%, which points to a good precision of the method. Correlation between the density measurements in mm Al eq and the DXA results was 0.9, for the density measurements in mm Al eq and the direct density measurements r was 0.5. The custom-made software was able to detect a change in bone mineralization of 6.6%.

The present method for bone densitometric analysis offers potentials for clinical evaluation of bone density and minute bone density changes in the jaw bone.