THE USE OF 3D VIRTUAL PLANNING AND 3D PRINTING FOR THE TREATMENT OF FACIAL ASYMMETRY : A CASE REPORT
2.2 . Operation The 3D printed surgical template was used during the bone harvesting of the anterior iliac crest where a rectangular piece of bone larger than the template was harvested , using the template to define the bone cuts . Thereafter the singlepiece bone graft was manually trimmed using the template as target model , which was afterwards grafted on the body of the left side of the mandible . The surgeon built up the mandible with the bone and fixated the different pieces with 6 mini screws
( KLS Martin , Germany ) of lengths 7 and 9 mm . 2.3 . Postoperative evaluation Postoperative CT was taken one month after the operation with the same settings as for the preoperative scan . The data was evaluated in the Amira software ( FEI , USA ). The preoperative and postoperative DICOM images were imported and the postoperative images were superimposed on the preoperative images via voxel based registration with mutual information 4 – 6 ( Fig . 3 ).
a . b . c . d .
Figure 3 . a . Preoperative skull ( gray ). b . Postoperative skull ( green ). c . Postoperative skull registered onto the preoperative skull frontal view , and d . lateral view
The preoperative extension was imported into the Amira project to visualize the changes between the simulated extension and the postoperative outcome ( Fig . 4 ). The postoperative bone was segmented and the extension was separately segmented then exported as STL files for further analysis .
A part comparison analysis between the postoperative extension and the simulated extension was done in the 3-matic software ( Materialise , Leuven , Belgium ) where the Euclidean distances between the surfaces were calculated ( Fig . 5 ).
Figure 4 . The simulated preoperative extension overlaid on the postoperative outcome after registration
a . b .
Figure 5 . a . The postoperative mandible with the postoperative segmented extension . b . The postoperative mandible and extension with the preoperative simulated extension
158 STOMA . EDUJ ( 2016 ) 3 ( 2 )