Bone Mineral Density and Bone Histomorphometry are Statistically Related

Purpose: The aim of this study was to evaluate how closely analysis of bone quality performed using the bone mineral density (BMD) values obtained by quantitative computerized tomography (QCT) reflected the histologic bone density. Materials and Methods: Eighteen patients requiring implant therapy underwent CT scanning. Their data were processed using Image Master software, and the BMD was calculated by measuring the Hounsfield units and relating those values to a phantom (Calibration Phantom, Quantitative Technologies). Each patient wore a radiographic-surgical template in which titanium cylinders were placed as a drilling guide for preparation of the implant site. The mouth regions where the titanium guides were placed (on the CT images and in the patient's mouth) corresponded to the implant sites where the BMD was measured and where tissue specimens for histomorphometric analysis retrieved. Forty specimens measuring 6 mm in length and 2 mm in diameter were obtained. Histomorphometric analysis was performed by digitizing the images, which were subsequently analyzed using the image analysis software IAS 2000. The bone volume (BV) was calculated as a percentage by dividing the area occupied by the mineralized bone over the entire microscopic field. Results: The results of the statistical analysis showed a Pearson correlation coefficient of 0.691 between the BV and BMD values, with a P value 0.01, which was considered significant. Discussion and Conclusion: The results of this study support the use of QCT to assess the bone quality before implant placement to improve the planning of implant treatment. Keywords: bone density, computerized tomography, histomorphometry