Meshmixer version 3

Our institute has used 1-mm slice bone setting images in default brain CT protocol since 2015. We used the first postoperative CT scan as the control point and the following CT scans for the BFR analysis. DICOM data of the brain CT was exported to generate a 3D model of the autologous bone flap of the CP using open-source 3D Slicer version 4.10.2 (http://www.slicer.org; Isomics, Inc, Cambridge, MA, USA). The same threshold level was used for each patient to render the whole skull 3D model and the autologous bone flap was precisely segmented using editing tools. Extracted bone flaps from each CT scans were exported in stereolithography file format and then imported to open-source Meshlab version 2016 (Visual Computing Lab; ISTI - CNR, Pisa, Italy) for volume measurement. If the 3D model of the autologous bone flap cannot be trimmed clearly from the 3D slicer, meshmixer version 3.5 (meshmixer.com">http://www.meshmixer.com; Autodesk, Inc., San Rafael, CA, USA) was used for additional modification of the autologous bone flap 3D models.

To design an STS for volume augmentation, STL file of each scanned cast was imported into the software (3Shape dental designer Version19, 3Shape; Copenhagen; Denmark). The outline of the STS was designed according to the incision line, which was placed 1.5 mm away from the adjacent teeth to protect the papilla and extended 4 mm down to the vestibular side (Figure 1B). The shape and the thickness of each STS were adapted to optimally fill the defect on top of the residual tissue and, thus, achieve the desired final soft‐tissue volume (Figure 1C). The designed STS together with the cast was exported as one entity into the software (Meshmixer Version 3.5, Autodesk) in order to extract the STS file from the cast file, while maintaining the same coordinate system (Figure 1D). The extracted STS was subsequently imported into the 3D analysis software (GOM Inspect) for further analysis.