In the field of tissue engineering, researches have been actively conducted to regulate stem cell fate by understanding the interaction between cell and materials. This approach is expected as a promising therapeutic method in the future medicine by utilizing differentiation of stem cells into desired cells or tissues using biomaterial. For this regenerative medicine, there exist lots of attempts to construct optimized structures of various shapes and sizes that can regulate the stem cell fate. In this review, we will empathize the topographic effect as stem cell niche on the mesenchymal stem cell (MSC) response (cell attachment, proliferation, and differentiation) according to the shape and size of the structure of the substrates, and comprehensively analyze the importance and the effect of shape and size of the surface topography.

Purpose Surgery for separating craniopagus twins involves many critical issues owing to complex anatomical features. We demonstrate a 3D printed model and virtual reality (VR) technologies that could provide valuable benefits for surgical planning and simulation, which would improve the visualization and perception during craniopagus surgery. Material & Methods We printed a 3D model extracted from CT images of craniopagus patients using segmentation software developed in-house. Then, we imported the 3D model to create the VR environment using 3D simulation software (Unity, Unity Technologies, CA). We utilized the HTC Vive (HTC & Valve Corp) head-mount-display for the VR simulation. Results We obtained the 3D printed model of craniopagus patients and imported the model to a VR environment. Manipulating the model in VR was possible, and the 3D model in the VR environment enhanced the application of user-friendly 3D modeling in surgery for craniopagus twins. Conclusion The use of the 3D printed model and VR has helped understand complicated anatomical structures of craniopagus patients and has made communicating with other medical surgeons in the field much easier. Further, interacting with the 3D model is possible in VR, which enhances the understanding of the craniopagus surgery as well as the success rate of separation surgery while providing useful information on diagnosing and surgery planning.

Fibular free flap reconstruction is the flap of the choice in long-span mandibular bone reconstruction. The most common disadvantage of the fibular flap is short bone height to install dental implant. Double barrel fibular flap has been tried, however, bulky flap in the oral cavity hinder its use. Titanium reconstruction plate has been used simultaneously with the free fibular flap to stabilize occlusion and to fix the fibular flap. In this study, titanium reconstruction plate was fixed in the lower border of the mandible and the fibular free flap was fixed in the superior border of the titanium plate to improve implant-crown ratio. This new technique improved the longevity of the dental prosthodontics with dental implants.

Purpose Interactive 3D visualization system through remote data transmission over heterogeneous network is growing due to the improvement of internet based real time streaming technology. Materials and Methods The current internet's IP layer has several weaknesses against IP spoofing or IP sniffing type of network attacks since it was developed for reliable packet exchange. In order to compensate the security issues with normal IP layer, we designed a remote medical visualization system, based on Virtual Private Network. Results Particularly in hospital, if there are many surgeons that need to receive the streaming information, too much load on the gateway can results in deficit of processing power and cause the delay. Conclusion End to end security through the network method would be required.

Purpose In this paper, we proposed alternate neighborhood system and reverse spread-direction approach for accurate and fast cellular automata-based image segmentation method. Materials and Methods On the basis of a simple but effective interactive image segmentation technique based on a cellular automaton, we propose an efficient algorithm by using Moore and designed neighborhood system alternately and reversing the direction of the reference pixels for spreading out to the surrounding pixels. Results In our experiments, the GrabCut database were used for evaluation. According to our experimental results, the proposed method allows cellular automata-based image segmentation method to faster while maintaining the segmentation quality. Conclusion Our results proved that proposed method improved accuracy and reduced computation time, and also could be applied to a large range of applications.