• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.6
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• pp.332-342
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• 2019

Objectives: Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation. Materials and Methods: This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee. Results: All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissue re-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae. Conclusion: Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.695-698
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• 2000

We studied the viability and function of islet with monomethoxy polyethylene glycol (mPEG) grafted onto its membrane. Islets were isolated from rat and were repeatedly reacted with activated mPEG (mw 5000) in order to increase grafting density. The density of grafted PEG on the islet membrane was confirmed by Fluorescein-PEG-NHS. An assessment of islet viability using AO / PI staining method showed that multiple PEGylation did not reduce islet viability. The function of PEG grafted islets was evaluated by measuring released insulin from islets. Insulin secreted from the PEGylated islets for 1 h did not show any significant difference compared to control (non-PEGylated) islets. In addition, PEGylated islets responded in the same pattern as control islets in the perifusion test.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.198-206
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• 2009

Purpose: The aims of this study were to assess the in vitro co-culturing pattern of isolated skin-derived precursor cells (SKPs) with a mixed demineralized bone (DMB) and fibrin glue scaffold and to evaluate in vivo osteogenesis after transplantation of autogenous SKPs with a these mixed scaffold in the animal's mandibular defects. Materials and Methods: We isolated SKPs from the ears of adult 4 miniature pigs. The isolated SKPs were co-cultured with a mixed DMB and fibrin glue scaffold in a non-osteogenic medium for 1, 2, and 4 weeks. Histological characteristics of in vitro co-cultured cells and scaffold were evaluated. $1{\times}10^7\;cells/100\;{\mu}l$ of autogenous porcine SKPs were grafted into the mandibular defects with a DMB and fibrin glue scaffold. In the control sites, only a scaffold was grafted, without SKPs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. Results: Homogeneously shaped skin-derived cells were isolated from porcine ear skin after 3 or 4 weeks of primary culture. In vitro osteogenic differentiation of SKPs was observed after co-culturing with a DMB and fibrin glue scaffold in a non-osteogenic medium. Von Kossa-positive bone minerals were also noted in the co-cultured medium at 4 weeks. As the culture time progressed, the number of observable cells increased. Trabecular new bone formation and osteocalcin expression were more pronounced in the SKP-grafted group compared to the control group. Conclusion: These findings suggest that autogenous SKP grafting with a DMB and fibrin glue scaffold can serve as a useful alternative to bone grafting technique.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.466-472
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• 2010

Introduction: This study examined the effect of recombinant human bone morphogenetic protein (rhBMP)-2 and $\beta$-tricalcium phosphate ($\beta$-TCP) on new bone formation in a rabbit calvarium using a rapid prototype titanium cap (RP Ti cap). Materials and Methods: Eight New Zealand white rabbits were used in this study. Hemispherical RP Ti caps (10 mm in diameter) were implanted subperiosteally on the rabbit calvaria. $\beta$-TCP was filled in the RP Ti cap in the control group, and rhBMP-2 soaked $\beta$-TCP was used in experimental group. The rabbits were sacrificed 2 and 4 weeks after the operation. The volume and pattern of newly formed bone was analyzed by micro computed tomography (CT). Results: Macroscopically, there were no abnormal findings in any of the animals. The micro CT images revealed new bone from the calvaria that expanded gradually toward the top of the titanium cap, particularly along the inner surface of the titanium cap in the experimental group at 4 weeks after grafting. There was no significant difference in new bone volume ratio between the control and experimental groups at 2 weeks after grafting. There was a statistically significant difference in the new bone volume ratio between the experimental ($14.1{\pm}1.8\;%$) and control ($7.2{\pm}1.5\;%$) groups at 4 weeks after grafting (P<0.01). Conclusion: The RP Ti cap can effectively guide new bone formation and rhBMP-2 can induce the new bone formation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.107-116
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• 2006

Purpose:Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(${\beta}$-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing & regeneration phase using histomorphometric and immunohistochemical analysis. Material & Methods:Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, ${\beta}$-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration & growth factor expression. Results: 1. The mean new bone volume formation was 28.99${\pm}$6.55%, 49.54${\pm}$5.47%, 69.09${\pm}$8.90% in autogenous grafted area, and 22.86${\pm}$5.56%, 24.00${\pm}$4.09%, 34.11${\pm}$3.37% in ${\beta}$-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than ${\beta}$-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. Conclusion:The authors we conclude that the autogenous bone graft was faster than ${\beta}$-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.

• The Journal of the Korea Contents Association
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• v.9 no.3
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• pp.164-174
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• 2009

As a condition for raising competitive force in the global fashion era that pursues diversity, originality is essential. This research is a study on fashion design able to seek high added value while considering the creative Korean Characters pattern as its motive. Therefore, this research hopes to examine the substantial methods regarding the creation of high added values centered on products utilizing Korean Characters as their motives in the fashion field. The specific research contents intend on, first, studying the formative specialties of Korean Characters; second, examining garment and fashion properties produced with Korean Character as their motive in domestic and foreign fashion shows; and third, understanding the methodology of applying the formation of Korean Characters pattern to fashion design. Hereby, this research suggests the design development regarding the geometrical formation of Korean Characters and the grafting of fashions as the way to inspire the images of domestic fashion brands in the global fashion market and heighten competitive force.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.1
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• pp.187-200
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• 1996

After loss of tooth, initial healing process is critical to preserve residual alveolar process. This study was conducted to compare the effect of hydroxylapatite particle synthetic graft and guided tissue regeneration procedure on healing of extraction wounds in 5 mongrel dogs. To investigate the maturity of bone and velocity of bone heating, bone-labeled tracers were used. After 16 weeks healing period, dogs were sacrificed. The specimens were treated with Villanueva bone stain. Fluorescence microscopy and polarized microscopy were performed to exam the pattern of bone formation in the extraction socket. The results were following ; 1. Pattern of bone regeneration in the group of hydroxylapatie graft and the group of membrane protection after hydroxylapatite graft was following ; bone regeneration was slow, regenerated bone was immature, and thickness of cortical layer was thin compare to that of untreated control group. 2. Cortical layers in membrane protected group were somewhat thicker but less condense to that of untreated control group. 3. Infiltration of inflammation cells were found in the groups using hydroxylapatite graft and membrane. We concluded that grafting of replamineform hydroxylapatite particles into the extraction socket delayed healing of the wound and disturbed the formation of cortical bone at the roof of extraction socket. The placement of expanded polytetrafluoroethylene membranes on the extraction socket promotes the bone regeneration. But newly formed bone in cortical layer consists of the cortico-cancellous bone in comparison with the cortical bone of the control group.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.101-116
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• 1989

Proplast and Porous Polyethylene which have porous structures as low-modulus polymers have been recently used in maxillofacial plastic and reconstructive surgery. The purpose of this study was to compare the response of adajacent tissue, new bone formation and stability after augmentation by differen methods of subperiosteal graft using proplast and purous polythylene in rabbit mandible. The augmentation procedure was carried out by dividing into two groups, A and B. A group consisted of subperiosteal graft on the cortex, and the other B group was made up only graft following artificial decortication in the mandibular body of rabbit. The experimental animals were sacrificed on the 1st, 2nd, 4th and 8th week after grafting for macroscopic and light microscopic examination. The samples extracted at the 6th postgrafting week were also used for biometric testing and scanning electron microscopic examination. The results obtained from this study were as follows : 1. Macroscopically, infection of graft site, deformation and migration of graft material were not observed in all experimental groups. 2. B group showed more rapid and increased bone formation and the greater stability than A group, and tissue response was similar to each other. 3. In the tissue response, macrophages and cellular infiltrations were observed in Proplast group, but few in PHDPE group. 4. In bone formation of A group, Proplast group showed no bone formation until the 8th week, but PHDPE group showed small quantity of osteoid tissue from the 2nd week and appositional bone growth with new bone formation at the 8th week. 5. In bone formation of B group, both Proplast and PHDPE group showed bone formation, but PHDPE group showed more rapid and larger bone formation. 6. In pattern of bone formation, Proplast group mainly showed appositional bone growth pattern connected with graft site. On the other hand, PHDPE group showed mixed pattern of new bone formation in the pore connective tissue with appositional bone growth from graff site. 7. The maximum mean values of shear stress were serially $111.3gf/mm^{2}$ in PHDPE of B group, $84.8gf/mm^{2}$ in PHDPE of A group, $32.9gf/mm^{2}$ in Proplast B group, and $15.7gf/mm^{2}$ in Proplast of A group. From above results, It was suggested that the capacity of bone formation and stability between bone and graft material were dependent on the pore size and structure of graft material itself, the state of graft site and tissue response.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

• Journal of Korean Dental Science
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• v.6 no.1
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• pp.13-21
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• 2013

Purpose: To report the successful results of using chin bone graft and autogenous tooth bone graft material (AutoBT) in alveolar cleft patients. Materials and Methods: Five patients with alveolar cleft defects underwent alveolar bone grafting. Three patients were treated using chin bone graft, and the other two patients underwent AutoBT graft. After implant site development using chin bone graft in the fi rst three cases, endosseous implant restorations were placed. In case #4 and 5, AutoBT graft material was placed to guide the normal eruption of partially impacted maxillary right canine and to the upper docking site after distraction osteogenesis. Result: Successful implant restorations with closure of the oronasal fistula were achieved in alveolar cleft defect reconstruction using either chin bone graft (Case #1, 2, 3) or AutoBT graft material (Case #4, 5). Case #4 showed enlarged follicle of the right maxillary canine, indicating a normal eruption guide pattern. Conclusion: Both chin bone graft and AutoBT graft showed favorable outcomes in reconstructing alveolar cleft defects. Autogenous tooth bone graft opens up the possibility of avoiding harvesting autogenous bone graft with complications and morbidities.