Copyright © 2019 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited. Importance of Three-Dimensional Modeling in Cranioplasty Hasan Emre Aydin, MD, PhD, y Ismail Kaya, MD,  Nevin Aydin, MD, z Ceren Kizmazoglu, MD, § Feridun Karakoc, PhD, jj Hidayet Yurt, jj and Resit Bugra Hu ¨semoglu, MD ô Abstract: Cranioplasty is a reconstruction operation made to protect intracranial structures. It is applied for the closure of bone defects occurring due to causes such as trauma, tumor, infection, and infarct. Many different products changing from autologous bone grafts to synthetic materials are used for cranioplasty. Three- dimensional printers that are among the popular innovations of today are used gradually more in medical area as in every field of life and they make the surgical operation easier. When customizable materials are combined with technology, the authors come across successful results and less complications. The aim of the authors’ study was to show a 3-dimensional modeling method in 2 patients the authors applied cranioplasty and the advantages provided by this method for the surgeon and the patient. Key Words: 3-Dimensional modeling, cranioplasty, reconstruction (J Craniofac Surg 2019;30: 713–715) C ranioplasty is a reconstruction operation made to protect calvarial remodeling intracranial structures and it is a severe struggle for the surgeon applying the operation. Cranioplasty operations are applied for the closure of bone defects occurring due to trauma, tumor or decompression operations, or infection. 1,2 Different materials such as autologous bone grafts, alloplastic materials such as titanium mesh, methyl methacrylate, calcium hydroxyapatite and polyetheretherketone some of which can be reconstructed easily, and porous polyethylene sheet are used in cranioplasty operations. 3–6 Three-dimensional printers that are among the popular innova- tions of today are used gradually more in medical area as in every field of life. The symmetrical structure is preserved, and a better image is acquired in cosmetic terms 7 with these printers. Materials without any significant difference in use have become customizable with 3-dimensional printers. The surgeon’s decision on which type of material is to be used during surgery and which would be appropriate is important. 8 Producing an exactly suitable model for the patient’s defect with a 3-dimensional printer using computer-aided modeling through preoperative axial 1-mm spiral computed tomography in patients who should have cranioplasty, surgical difficulties were prevented, and operation duration was shortened through preoperation simu- lation possibility and thus its effect on surgical plan was presented by the provision of patient satisfaction. 9 The aim of our study was to demonstrate 3-dimensional model- ing method we applied to cover the calvarial defect in 2 patients and the advantages provided by this method for both the surgeon and the patient. PATIENT 1 Images of the patient acquired through computed tomography (CT) device were examined through free imaging software. After the operated section of the patient’s cranium was exam- ined, it was considered to make an individual molding from the plastic material with 3-dimensional printers to acquire the most suitable piece to be in the open cranial section with a nonuniform shape of nearly 6.50  5.50 cm. Design stages were discussed so that the desired mold could be modeled using 3-dimensional design (CAD) programs and it was decided that it could be designed as the following with the CAD softwares (nonmedical) available in our laboratory. In the radiological imaging, the open cranial section was in a position perpendicular to the screen (monitor) and thus screenshots in jpeg file format were captured. These images were loaded to a 2- dimensional drawing program. To bring the image loaded on the drawing program without any scale to its original dimensions, the real distance between 2 points on the image captured from the cranium on DICOM imaging software was taken as reference and the required scale was applied on the image and it was brought to the scale of 1:1. Then the control points in the cranial sections which should be covered were determined in a 2-dimensional drawing platform and the image of the mold from above was acquired through the B- spline (NURBS) curve passing through these points (Fig. 1A). A 3- dimensional solid model was acquired by giving a thickness of 15 mm in a CAD program using the drawn B-spline curve. With the 3-dimensional modeling techniques and editing com- mands, the final form of the mold was acquired on a 3-dimensional solid model using these data (Fig. 2). The solid model was transferred into stl format in suitable resolution so that the 3-dimensional solid model of the mold to be used for acquiring the piece to be in the cranium can be produced on 3-dimensional printer. Mold data in stl format was separated into layers (segments) of 0.25 mm with a software and was produced from ABS material in segments on 3-dimensional printer using Fused Deposition Model- ing (FDM) technology. Methyl methacrylate (Synicem, Synergie Ingeniere Medicale S.A. R. L. Z. A De Angle 19370 Chamberet France) used during From the  Department of Neurosurgery, Medical Faculty, Dumlupinar University, Kutahya; y Department of Pharmacology, Medical Faculty, Osmangazi University, Eskisehir; z Department of Radiology, Medical Faculty, Dumlupinar University, Kutahya; § Department of Neurosur- gery, Medical Faculty, Dokuz Eylu ¨l University, Izmir; jj Department of Machine Engineering, Engineering Faculty, Dumlupinar University, Kutahya; and ô Department of Biomechanics, Health Science Institute, Dokuz Eylul University School of Medicine, Izmir, Turkey. Received December 19, 2017. Accepted for publication September 26, 2018. Address correspondence and reprint requests to Ismail Kaya, MD, Department of Neurosurgery, Medical Faculty, Dumlupinar University, Kutahya, Turkey 43040; E-mail: dr.ikaya85@gmail.com The authors report no conflicts of interest. Copyright # 2019 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000005121 ORIGINAL ARTICLE The Journal of Craniofacial Surgery  Volume 30, Number 3, May 2019 713