• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.13.1-13.8
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• 2017

Background: Oronasal/antral communication, loss of teeth and/or tooth-supporting bone, and facial contour deformity may occur as a consequence of maxillectomy for cancer. As a result, speaking, chewing, swallowing, and appearance are variably affected. The restoration is focused on rebuilding the oronasal wall, using either flaps (local or free) for primary closure, either prosthetic obturator. Postoperative radiotherapy surely postpones every dental procedure aimed to set fixed devices, often makes it difficult and risky, even unfeasible. Regular prosthesis, tooth-bearing obturator, and endosseous implants (in native and/or transplanted bone) are used in order to complete dental rehabilitation. Zygomatic implantology (ZI) is a valid, usually delayed, multi-staged procedure, either after having primarily closed the oronasal/antral communication or after left it untreated or amended with obturator. The present paper is an early report of a relatively new, one-stage approach for rehabilitation of patients after tumour resection, with palatal repair with loco-regional flaps and zygomatic implant insertion: supposed advantages are concentration of surgical procedures, reduced time of rehabilitation, and lowered patient discomfort. Cases presentation: We report three patients who underwent alveolo-maxillary resection for cancer and had the resulting oroantral communication directly closed with loco-regional flaps. Simultaneous zygomatic implant insertion was added, in view of granting the optimal dental rehabilitation. Conclusions: All surgical procedures were successful in terms of oroantral separation and implant survival. One patient had the fixed dental restoration just after 3 months, and the others had to receive postoperative radiotherapy; thus, rehabilitation timing was longer, as expected. We think this approach could improve the outcome in selected patients.

• Journal of Biomedical Engineering Research
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• v.43 no.2
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• pp.116-123
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• 2022

This study analyzes the Mechanical properties of a medical bone plate by 3D printing. With the recent development of 3D printing technology, it is being applied in various fields. In particular, in the medical field, the use of 3D printing technology, which was limited to the existing orthosis and surgical simulation, has recently been used to replacement bones lost due to orthopedic implants using metal 3D printing. The field of application is increasing, such as replacement. However, due to the manufacturing characteristics of 3D printing, micro pores are generated inside the metal printing output, and it is necessary to reduce the pores and the loss of mechanical properties through post-processing such as heat treatment. Accordingly, the purpose of this study is to analyze the change in mechanical performance characteristics of medical metal plates manufactured by metal 3D printing under various conditions and to find efficient metal printing results. The specimen to be used in the experiment is a metal plate for trauma fixation applied to the human phalanx, and it was manufactured using the 'DMP Flex 100(3D Systems, USA), a metal 3D printer of DMLS (Direct Metal Laser Sintering) method. It was manufactured using the PBF(Powder Bed Fusion) method using Ti6Al4V ELI powder material.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.414-427
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• 2023

Implantable bioabsorbable combination products undergo inherent degradation and systemic absorption within the physiological environment, thereby streamlining the therapeutic regimen and obviating the imperative for invasive extraction procedures. This inherent property not only enhances patient convenience and therapeutic efficacy but also underpins a paradigm of support characterized by heightened safety parameters. Within the regulatory landscapes of Korea, the United States, and Europe, implantable bioabsorbable combination products are meticulously classified into distinct categories, either as pharmaceutical implants or as implantable medical devices, depending on their primary mode of action. This scholarly investigation systematically examines the regulatory frameworks governing implantable bioabsorbable combination products in South Korea, the United States, and Europe. Notable discrepancies across national jurisdictions emerge concerning regulatory specifics, including terminology, product classification, and product name associated with these products. The conspicuous absence of standardized approval regulations presents a formidable barrier to the commercialization of these advanced medical devices. This academic discourse passionately emphasizes the critical need for formulating and implementing a sophisticated regulatory framework capable of streamlining the product approval process, thereby paving the way for a seamless path to commercializing implantable bioabsorbable combination products.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.338-344
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• 2016

Implant supported removable partial denture (ISRPD) using the implants enables favorable rehabilitation by complementing biomechanical limitations of the conventional removable partial denture (RPD). However, continuous recall check is necessary for evaluation of the mechanical and biological complications to ensure good long-term prognosis of ISRPD. This clinical report describes the complication and management in patient of Kennedy class I edentulism with ISRPD using healing abutment. The wear and fracture of healing abutment occurred at 36 months after delivery. So, healing abutment was replaced by connecting $Locator^{(R)}$ abutment for altering into the implant retained partial overdenture.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.136-140
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• 2006

In this study, we investigated the synergistic effects of Staphylococcus aureus extracts (membranes and walls) and lipopolysaccharide (LPS) derived from Escherichia coli on tumor necrosis factor (TNF) production in the pathogenesis of silica-induced inflammation. The synergistic induction of TNF by silica particles $(<20\;{\mu}m)$ in combination with either S. aureus extracts or LPS was examined in J774A.1 cell cultures. Media from the treated and untreated cell cultures were assayed for TNF, using the mouse WEHI 164 cell cytotoxicity assay and enzyme immunoassay. Cells exposed simultaneously to silica and $0.5\;{\mu}g/ml$ S. aureus extracts (or 0.5 ng/ml of LPS) produced a significantly higher level of TNF than those produced by the inducer alone. Our results indicate that device-associated infections (or pyrogen contamination) could enhance inflammatory responses, because of particles produced by the wear of medical implants or particulate biomaterials used for clinical purposes.

• Biomedical Science Letters
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• v.12 no.3
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• pp.161-170
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• 2006

A new piperazine derivative, 8J-8029, is a synthetic anti-cancer agent which exhibits both microtubule and topoisomerase II inhibiting activities. In this study, we investigated the ability of 8J-8029 for anti-angiogenesis and apoptosis. 8J-8029 decreased the bFGF-induced angiogenesis in the CAM and the mouse Matrigel implants, in vivo. 8J-8029 inhibited the proliferation, migration, invasion, tube fonnation, and expression of MMP-2 in BAECs. In addition, 8J-8029 reduced the cell viability in HepG2 cells, caused the production of fragmented DNA and the morphological changes corresponding to apoptosis. 8J-8029 also elicited the release of cytochrome c and the activation of caspase-3. Taken together, these results suggest 8J-8029 may be a candidate for anti-cancer agent with the ability to inhibit the angiogenesis of endothelial cells and to induce the apoptosis of tumor cells.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.896-902
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• 2005

An orthopedic surgeon normally gets the operational parameters of total knee arthroplasty from medical images(CT, MRI). Anatomical axis, mechanical axis, the width and height of femur, or tibia are the most important parameters related with accomplishment of TKA. This paper presents a methodology of simulation that virtually operates TKA according to 2D medical images. Using this simulator, some important parameters for operation can be achieved before hand. The simulator provides the 3D computational model of a knee joint and then derives the proper size of implant corresponding to the joint. The whole process of TKA can be simulated such as clipping a knee joint, assembling the joint and its implants, visualizing all the operation steps, deriving some crucial parameters such as anatomical axis and cutting thickness, and predicting the result of TKA. Some examples are given and discussed to validate the methodology.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.915-918
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• 2005

Advances in Information Technology and in Biomedicine have created new uses for CAD technology with many novel and important biomedical applications. Such applications can be found, for example, in the design and modeling of orthopedics, medical implants, and tissue modeling in which CAD can be used to describe the morphology, heterogeneity, and organizational structure of tissue and anatomy. CAD has also played an important role in computer-aided tissue engineering for biomimetic design, analysis, simulation and freeform fabrication of tissue scaffolds and substitutes. And all the applications require precision geometry of the organs or bones of each patient. But the geometry information currently used is polygon model with none solid geometry and is so rough that it cannot be utilized for accurate analysis, simulation and fabrication. Therefore a case study is performed to deduce a transformation method to build free form surface from a rough polygon data or medical images currently used in the application. This paper describes the transformation procedure in detail and the considerations for accurate organ modeling are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.988-991
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• 2015

3D printing technology is instrument that can create real objects in three-dimensional space, as printed on paper, if the three-dimensional designs are made. 3D printing technology has been recently used in various field of medicine, and also biomedical application of three dimensional printing technology remains one of the most important research topics until now. 3D printing technology is causing a revolutionary change in the overall automotive manufacturing, aerospace, marine, medical and so on. The medical industry applications of current 3D printer are a virtual simulation, custom medical implants manufactured, practice of medical personnel. In this study, we analyzed 3D printing technology and application cases for medical services.

• Journal of Biomedical Engineering Research
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• v.40 no.2
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• pp.55-61
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• 2019

Recently, various researches on materials and equipment have been actively conducted to overcome the limitations of conventional output methods due to the increase of diversity of 3D printing materials and to adopt an output method suitable for the characteristics of each material. As the range applicable to outputable materials is expanded, manufacturing of medical devices applied to patients is in a more rapid growth trend than other fields. In this study, we investigated the suitable materials for fabricating 3D printer using photocurable resin. As a result, one suitable material was selected through biological safety experiment and thermal stability experiment. Next, to optimize the output of the selected materials, we have developed a system that optimizes the equipment according to the characteristics of the material. The results of this study enabled the implementation of personalized medical implants that could not be made from 3D printer dependent materials, thereby overcoming the limitations of existing 3D printer output conditions and dedicated materials.