• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.1
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• pp.47-54
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• 2017

The atrophy of edentulous ridge and pneumatization of the maxillary sinus often limit the volume of bone available for implant placement on maxillary posterior teeth. Most clinicians suffer difficulties from poor bone quality and quantity on maxillary posterior site. Thus, the success of maxillary posterior implant surgery depends on the increase of the available bone and obtaining a good initial stability of the implant after maxillary sinus reconstruction. The maxillary sinus augmentation methods include a crestal approach and a lateral approach. Less morbidity and complications after operation is major advantage to sinus augmentation using crestal approach than lateral approach. However, when the residual ridge height is ${\geq}6mm$, it is known that crestal approach is appropriate. Also delayed implantation after sinus augmentation is recommended in severely atrophic ridge. We present the three cases of implant placement simultaneously sinus augmentation using crestal approach in posterior maxilla site with ${\leq}3mm$ of residual alveolar bone.

• Macromolecular Research
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• v.15 no.1
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• pp.51-58
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• 2007

The approach studied in the present work produced an exfoliated state of clay layers via confinement of the charged nano-sized polystyrene (PS) beads within the gallery of swollen pristine clay. It was demonstrated that adsorption of the polymer nanobeads dramatically promotes expansion of the clay gallery. A comparative study of incorporation was conducted by employing organo-modified clay along with two different colloid polymer systems: electrostatically stabilized PS nanobeads and cationic monomer-grafted PS nanobeads. The mechanism of adsorption of the monomer-grafted polymer beads onto clay via cationic exchange between the alkyl ammonium group of the polymer nanobeads and the interlayer sodium cation of the layered silicate was verified by using several techniques. As distinct from the polymer nanobeads formed using conventional miniemulsion polymerization method, competitive adsorption of stabilizing surfactant molecules was be prevented by grafting the surface functional groups into the polymer chain, thereby supporting the observed effective adsorption of the polymer beads. The presence of surface functional groups that support the establishment of strong polymer-clay interactions was suggested to improve the compatibility of the clay with the polymer matrix and eventually play a crucial role in the performance of the final nanocomposites.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.379-386
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• 2014

Background Vulvar defects result chiefly from oncologic resection of vulvar tumors. Reconstruction of vulvar defects restores form and function for the purpose of coitus, micturition, and defecation. Many surgical options exist for vulvar reconstruction. The purpose of this article is to present our experience with vulvar reconstruction. Methods From 2007 to 2013, 43 women presented to us with vulvar defects for reconstruction. Their mean age at the time of reconstruction was 61.1 years. The most common cause of vulvar defect was from resection of vulvar carcinoma and extramammary Paget's disease of the vulva. Method s of reconstruction ranged from primary closure to skin grafting to the use of pedicled flaps. Results The main complications were that of long term hypertrophic and/or unaesthetic scarring of the donor site in 4 patients. Twenty-two patients (51%) were able to resume sexual intercourse. There were no complications of flap loss, wound dehiscence, and urethral stenosis. Conclusions We present a subunit algorithmic approach to vulvar reconstruction based on defect location within the vulva, dimension of the defect, and patient age and comorbidity. The gracilis and gluteal fold flaps are particularly versatile and aesthetically suited for reconstruction of a variety of vulvar defects. From an aesthetic viewpoint the gluteal fold flap was superior because of the well-concealed donor scar. We advocate the routine use of these 2 flaps for vulvar reconstruction.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.2
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• pp.129-136
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• 1991

The fibrin sealant was first designed as an alternative to surgical suture for the purpose of surface-to-surface union especially in parenchymal organs like the liver, spleen and kidney. The clinical application of currently used fibrin sealant was first introduced in 1972. The fibrin sealant consists of principal two components; lyophilized human fibrinogen and bovine thrombin. The fibrinogen component also contains coagulation factor XIII. A solution of aprotinin, an inhibitor of fibrinolysis is used to dissolve the fibrinogen and to provide the first component, and a solution of calcium chloride is also used to provide the second component. From July to December in 1990, during 6 months, we used fibrin sealant in the 28 patients of 33 various cases, in the following ways; supportive application of fibrin sealant after free autogenouse nerve graft for the repair of inferior alveolar nerve, facial nerve or accessory nerve, treament of hemangioma or lymphangioma to thrombosize and lead to the tumor shrinking, skin grafting to stimulate the adhesion and tissue repair, bone grafting in the patients of cleft alveolus, mandibular reconstruction or orthognathic surgery to facilitate the knitting of bone chips, tissue adhesion after tumor resection, radical neck dissection or flap reconstructions, and supportive adhesion of external auditory cannal after TMJ surgery via postauricular approach. No adverse effects were observed, none of the patients developed hepatitis or other blood transmitted disease, and the wound healing were acceptable.

• Macromolecular Research
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• v.16 no.2
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• pp.139-148
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• 2008

Biodegradable and elastic poly(L-lactide-co-$\varepsilon$-caprolactone) (PLCL) was electrospun to prepare nanofibers, and N-isopropylacrylamide (NIPAAm) was then grafted onto their surfaces under aqueous conditions using $^{60}Co-{\gamma}$ irradiation. The graft yield increased with increasing irradiation dose from 5 to 10 kGy and the nanofibers showed a greater graft yield compared with the firms. SEM confirmed that the PLCL nanofibers maintained an interconnected pore structure after grafting with NIPAAm. However, overdoses of irradiation led to the excessive formation of homopolymer gels on the surface of thc PLCL nanofibers. The equilibrium swelling and deswelling ratio of the PNIPAAm-g-PLCL nanofibers (prepared with 10 kGy) was the highest among the samples, which was consistent with the graft yield results. The phase-separation characteristics of PNIPAAm in aqueous conditions conferred a unique temperature-responsive swelling behavior of PNIPAAm-g-PLCL nanofibers, showing the ability to absorb a large amount of water at < $32^{\circ}C$, and abrupt collapse when the temperature was increased to $40^{\circ}C$. In accordance with the temperature-dependent changes in swelling behavior, the release rate of indomethacin and FITC-BSA loaded in PNIPAAm-g-PLCL nanofibers by a diffusion-mediated process was regulated by the change in temperature. Both model drugs demonstrated greater release rate at $40^{\circ}C$ relative to that at $25^{\circ}C$. This approach of the temperature-controlled release of drugs from PNIPAAm-g-PLCL nanofibers using gamma-ray irradiation may be used to design drugs and protein delivery carriers in various biomedical applications.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.50.1-50.6
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• 2016

Background: The aim of this study was to evaluate the clinical outcomes of implants that were placed within the maxillary sinus that has a perforated sinus membrane by the lateral window approach. Methods: We examined the medical records of the patients who had implants placed within the maxillary sinus that has a perforated sinus membrane by the lateral approach at the Department of Oral and Maxillofacial Surgery of Chonnam National University Dental Hospital from January 2009 to December 2015. There were 41 patients (male:female = 28:13). The mean age of patients was $57.2{\pm}7.2years$ at the time of operation (range, 20-76 years). The mean follow-up duration was 2.1 years (range, 0.5-5 years) after implant placement. Regarding the method of sinus elevation, only the lateral approach was included in this study. Results: Ninety-nine implants were placed in 41 patients whose sinus membranes were perforated during lateral approach. The perforated sinus membranes were repaired with a resorbable collagen membrane. Simultaneous implant placements with sinus bone grafting were performed in 37 patients, whereas delayed placements were done in four patients. The average residual bone height was $3.4{\pm}2.0mm$ in cases of simultaneous implant placement and $0.6{\pm}0.9mm$ in cases of delayed placement. Maxillary bone graft with implant placement, performed on the patients with a perforated maxillary sinus membrane did not fail, and the cumulative implant survival rate was 100%. Conclusions: In patients with perforations of the sinus mucosa, sinus elevation and implant placement are possible regardless of the location and size of membrane perforation. Repair using resorbable collagen membrane is a predictable and reliable technique.

• Journal of the Korean Burn Society
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• v.23 no.1
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• pp.20-24
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• 2020

Diabetic patients have an increased risk of burn injuries on foot. Because of their diabetic neuropathy, they could contact with hot water or warming device without being aware of it. Split-thickness skin graft (STSG) is successful in treatment of various wound types; however, donor site wounds are sometimes problematic, and complications such as pain and impaired healing often occur. Although, donor site wounds in healthy young individuals can rapidly heal without complications, the wound-healing capacity of elderly patients or those with a comorbidity has been reported to be low. The dermatome is the most commonly used tool because it can harvest a large skin graft in one attempt. However, it is difficult to harvest tissues if the area is not flat. Furthermore, because the harvested skin is usually rectangular, additional skin usually remains after skin grafting. Therefore, use of razor blade and fragmented STSG on a large defect area is advantageous for harvesting a graft with a desired size, shape, and thickness. From January 2018 to July 2018, fragmented STSG was used in 9 patients who suffered from burn induced open wound on foot with diabetic neuropathy. With this approach, healing process was relatively rapid. The mean age of patients was 70 (57~86 years) and all of 9 patients had diabetes mellitus type 2. In all patients, the skin graft on the defect site healed well and did not result in complications such as hematoma or seroma.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.187-193
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• 2020

The purpose of this study is to study the methodology of deriving a policy that activates artificial intelligence from the governmental perspective in order to induce corporate growth by effectively grafting artificial intelligence technology into society and thereby improve individual and national competitiveness by creating new jobs. In order to derive activation plans, 1) detailed investigation of the domestic environment, 2) discovery of priority support fields and models that can be applied to artificial intelligence, 3) preparation of guidelines for activation and introduction, 4) specific methods for promoting and activating artificial intelligence Should be presented. The proposed artificial intelligence activation method performs a procedure to verify and confirm the effectiveness of artificial intelligence nurturing through a multi-faceted approach. The multi-faceted analysis approach includes business ecosystem aspects, industry-specific aspects including companies, technology fields, policy aspects, public and non-public services aspects, government-led and private-led aspects. Therefore, it can be reviewed as a method of inducing activation in various forms. In the future research field, it is necessary to prove the effectiveness of the proposed activation plan based on empirical data on artificial intelligence-based services. The expected effect of this study is to contribute to support the development of artificial intelligence technology and to establish related policies.

• Membrane Journal
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• v.31 no.3
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• pp.212-218
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• 2021

It is inevitable to generate incomplete combustion gases when mankind utilizes fossil fuels. From this point of view, gas separation process of combustion gas suggests the possibility of recycling CO gas. In this study, we fabricated a facilitated transport polymeric composite membrane for CO separation using AgBF₄ and HBF₄. The copolymer was synthesized via free-radical polymerization of poly(vinyl alcohol) (PVA) as a main chain and acrylic acid (AA) monomer as a side chain. The polymer synthesis was confirmed by FT-IR and the interactions of graft copolymer with AgBF₄, and HBF₄ were characterized by TEM. PVA-g-PAA graft copolymer membranes showed good channels for facilitated CO transport. In this perspective, we suggest the novel approach in CO separation membrane area via combination of grafting and facilitated transport.

• Journal of Periodontal and Implant Science
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• v.44 no.5
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• pp.216-221
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• 2014

Purpose: This retrospective study compares the amount of bone resorption around implants between an autogenous tooth bone graft (AutoBT) and a synthetic bone graft after a bone-added crestally approached sinus lift with simultaneous implant placements. Methods: In all, 37 patients participated in this study. Seventeen patients were grouped as group I and underwent an AutoBT-added sinus lift using the crestal approach. The remaining 20 patients were grouped as group II and underwent synthetic bone grafting. Both groups received the implant placements simultaneously. Of the 37 participating patients, only 22 patients were included in the final results: Eleven patients of group I and 11 patients of group II. Before the surgery, the distance from the alveolar crest to the sinus floor was measured using panoramic radiography. After the surgery, the distance was measured again from the neck of the implant thread to the most superior border of the added graft materials. Then, the amount of sinus lift was calculated by comparing the two panoramic radiographs. After a year, a panoramic radiograph was taken to calculate the resorption of the bone graft material from the radiograph that was taken after the surgery. The significance of the resorption amount between the two types of graft materials was statistically analyzed. Results: The bone height was increased to an average of 4.89 mm in group I and 6.22 mm in group II. The analysis of panoramic radiographs 1 year after the surgery showed an average bone resorption of 0.76 mm and 0.53 mm, respectively. However, the degree of lifting (P=0.460) and the amount of bone-grafted material resorption (P=0.570) showed no statistically significant difference. Conclusions: Based on this limited study, AutoBT can be considered a good alternative bone graft to a synthetic bone graft in a bone-added sinus lift, when extraction is necessary prior to the surgery.