Digital image ratio: a new radiographic method for quantifying changes in alveolar bone. Part II: Clinical application

Abstract

In a previous paper (1) we have described a new technique, Digital Image Ratio (DIR), which theoretically avoids some of the drawbacks of quantitative digital subtraction radiography. DIR allows one to directly compute and visualize bone-mass-ratio changes. In this second part, DIR analysis was used to examine 20 sites in 8 patients undergoing regenerative periodontal therapy. Standardized reproducible radiographs of these 20 sites were taken before and 12 months after surgery. Ten experimental sites were treated with two types of bone graft substitute (Natural Coral and Natural Coral + Collagen), and ten control sites by debridement alone.None of the experimental sites had a density ratio below 1, with 1 indicating no change.The range of error was evaluated to be ± 0.07 (0.93 -1.07). The experimental sites showed a mean increase in bone density of 18% (1.18), which increased to 23% (1.23) for sites filled with natural coral alone. All the control sites had values close to 1.00 (1.00 ± 0.07) except for three sites, which showed a loss of bone density ranging from 9 to 15%. It is thus possible to compare and quantify the changes in experimental and control sites in the same patient using the percent gain or loss of bone density. This demonstrates that DIR may be suitable for clinical applications and can be used in clinical analysis, where bone changes are expected.

Tomographic late evaluation of xenogeneic bone grafts in sockets of impacted third molars

“…Some studies have used both conventional intraoral and panoramic radiographs. 2 , 7 , 8 , 10 , 11 , 15 Others have compared the images obtained in panoramic radiographs and tomographies evaluating biomaterials, proximity of the third molar to the lower alveolar nerve and external root resorption. 3 , 6 , 18 , 20 , 22 The results confirm that cone beam computed tomography (CBCT) has better image quality, better measurement accuracy, less distortion and, mainly, allows the visualization of the region of interest (ROI) without overlapping other structures.…”