Measure bone volume and density changes of sites grafted with bone allografts and a titanium mesh on cone-beam computed tomography: a technique

The aim of this study was to introduce a novel method to evaluate volumetric and density changes of the augmented sites. A ridge augmentation procedure, using particulate bone allografts and a titanium mesh, was performed on the posterior edentulous mandible of 3 participants. Cone-beam computed tomography was taken preoperatively (1st scan), immediately (2nd scan), and 5 months (3rd scan) after the surgery. The grafted area was segmented on the 2nd and 3rd scans, using the 1st scan as the reference. The volume of the grafted area and the newly formed bone-graft complex that is defined by a preselected threshold was then determined. The bone mineral density (BMD) of the grafted area was determined by comparing gray-scale histograms of the grafted area for the 2nd and 3rd scans using the cortical bone adjacent to the grafted area as the reference. The mean volumetric shrinkage was 13.5%. The BMD increase was 4.65%. The mean error in determining cortical bone density between the scans was 1.69%. A novel technique to measure bone volume and density changes after bone augmentation was described. The low measurement/scanning error suggested that this technique is reliable and reproducible.