1 Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, College of Medicine, University of Ulsan , Seoul, Republic of Korea.
2 Department of Oral and Maxillofacial Surgery, Asan Medical Center, College of Medicine, University of Ulsan , Seoul, Republic of Korea.
Tissue Eng Part C Methods. 2018 May;24(5):255-262. doi: 10.1089/ten.TEC.2017.0474.
Bone graft materials are commonly used to regenerate various bone defects, but their application is often limited because of the complex defect shape in various clinical conditions. Hence, customized bone grafts using three-dimensional (3D) printing techniques have been developed. However, conventional simple bone defect models are limited for evaluating the benefits and manufacturing accuracy of 3D-printed customized bone grafts. Thus, the aim of the present study was to develop a complex-shaped bone defect model. We designed an 8-shaped bony defect that consists of two simple circles attached to the rabbit calvarium. To determine the critical-sized defect (CSD) of the 8-shaped defects, 5.6- and 7-mm-diameter trephine burs were tested, and the 7-mm-diameter bur could successfully create a CSD, which was easily reproducible on the rabbit calvarium. The rate of new bone formation was 28.65% ± 8.63% at 16 weeks following creation of the defect. To confirm its efficacy for clinical use, the 8-shaped defect was created on a rabbit calvarium and 3D computed tomography (CT) was performed. A stereolithography file was produced using the CT data, and a 3D-printed polycaprolactone graft was fabricated. Using our 8-shaped defect model, we were able to modify the tolerances of the bone graft and calvarial defect to fabricate a more precise bone graft. Customized characteristics of the bone graft were then used to improve the accuracy of the bone graft. In addition, we confirmed the fitting ability of the 3D-printed graft during implantation of the graft. Our 8-shaped defect model on the rabbit calvarium using a 7.0-mm trephine bur may be a useful CSD model for evaluating 3D-printed graft materials.
骨移植材料常用于再生各种骨缺损，但由于各种临床情况下的复杂缺损形状，其应用往往受到限制。因此，已经开发了使用三维（3D）打印技术的定制骨移植物。然而，传统的简单骨缺损模型对于评估 3D 打印定制骨移植物的益处和制造精度是有限的。因此，本研究的目的是开发一种复杂形状的骨缺损模型。我们设计了一种 8 字形骨缺损，由附着在兔颅骨上的两个简单圆形组成。为了确定 8 字形缺损的临界尺寸缺损（CSD），测试了 5.6- 和 7-mm 直径的环锯，7-mm 直径的环锯能够成功地创建 CSD，并且在兔颅骨上很容易重现。缺损形成后 16 周，新骨形成率为 28.65%±8.63%。为了确认其在临床应用中的有效性，在兔颅骨上创建了 8 字形缺损并进行了 3D 计算机断层扫描（CT）。使用 CT 数据生成立体光刻文件，并制造 3D 打印聚己内酯移植物。使用我们的 8 字形缺损模型，我们能够修改骨移植物和颅骨缺损的公差，以制造更精确的骨移植物。然后，使用定制的骨移植物特征来提高骨移植物的准确性。此外，我们在植入移植物期间确认了 3D 打印移植物的适配能力。我们使用 7.0-mm 环锯在兔颅骨上的 8 字形缺损模型可能是评估 3D 打印移植物材料的有用 CSD 模型。
