## 3 Results  
The cases included in the study were divided into two groups: The first group (1) included those cases in which the initial SB volume used during surgery was known, because they were custom-made implanted SB blocks (Table 2), hence, blocks designed and manufactured on demand specifically by the manufacturing company. The increase is considered with respect to the initial situation, i.e., the empty defect (considered as the 0 mm\({}^{3}\) reference); comparison is made between grafted SB (initial volume of SB) and final volumetric increase. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Cases**} & **Region of Interest** & **Final Volumetric** & \multirow{2}{*}{**Follow up Time**} & **Initial Volume of** \\  & **(ROI)** & **Increase [mm\({}^{3}\)]** & & **SB [mm\({}^{3}\)]** \\ \hline Case One & Dental & 391 & 13 months & 277 \\ Case Three & Dental & 605 & 6 months & 781 \\ Case Five & MCF & 10,190 & 24 months & 17831 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Volumetric comparison on cases made with pre-customized SB blocks. Figure 3: Example of the pre-operative model imported as a mesh file (in gray) and the post-operative template imported as a CAD body file (in blue). The second group (2) included those other cases that did not have custom-made implants. Therefore, the surgeon had to cut and hand remodel standard blocks (Table 3). Here, again, the increase is considered with respect to the initial situation, i.e., the empty defect (considered as the 0 mm\({}^{3}\) reference); comparison between grafted SB (initial volume of SB not known) and the final volumetric increase was, hence, not possible. These last cases resulted in a lack of exact bone grafted volume information, and, thus, it was not possible to make a direct and precise comparison between the resulting volume and the initially implanted volume. Nevertheless, these cases are relevant given the intent of this work to assess these types of situations, being frequent in current common clinical practice. Table 2 shows the volumetric increase in all studied cases with respect to initial conditions. Group 1 collects three cases in which the initial volume of SB is known. Moreover, in one dental case, the resulting volume was greater than the initial volume of implanted SB. Importantly, after 7 to 9 months the new bone always represented a large part of the volume (80.8%), and SB was almost completely reabsorbed (0.5%). These data were consistent with previous results from the literature [29]. Group 2 shows instead that all patients had new bone generation because in the pre-surgery CT a lack of bone was evident, and in post-surgery CT the defect is corrected by the formation of new bone. This could be established because native bone and SB have different densities. Therefore, they can be distinguished, and such difference can be measured by HU. This difference in density was particularly noticeable in case #5, hence, presented in Figure 4a,b, where the red circle (the defective bone) had a smaller white part (the newly formed bone) in the same area. This deduction was straightforward: New bone was clearly visible after two years post-surgery. Further details for each case are here described:  
* Case #1: The patient responded well to the implant: By comparing the CT before the operation and the CT 13 months after surgery, a volumetric increase of 114 mm\({}^{3}\) was calculated and no signs of inflammation. It was possible to proceed with the design of the dental implant, after checking that the body integrated the implant and the graft had allowed the regeneration of new bone. The project established dental implant positioning, which is important because they replaced the missing tooth roots. The surgery allowed the dentist to have the right plan specifications, for example, the distance between the teeth or the depth of the implant. One year later the patient still did not show any inflammation or foreign body reaction against implanted material so the implants could be fitted.