• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.276-284
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• 2008

Purpose: The purpose of this study was to observe the effect of calcium and vitamin D to the titanium implant osseointegration in the osteoporosisinduced animal model. Material and method: Thirty-two rats, 10 weeks of age, were divided into two groups: experimental group was ingested additional calcium and vitamin D, and a control group was not. Titanium screw implant(diameter, 2.0 mm; length, 3.5 mm; pitch-height 0.4 mm) were placed into tibia of 32 rats, 16 in the control group and 16 in the experimental group. The rats were sacrificed at 1, 2, 4 and 8 weeks after implantation for histopathologic examination, histomorphometric analysis and immunohistochemistry with fibronectin and collagen type I antibody. Result: In histopathological findings, newly formed bone was seen at 2 weeks and became lamellar bone at 4 weeks, and mature trabecullar bone was seen at 8 weeks in experimental group. In control group, thickness of regenerated bone increased till 4 weeks gradually and trabecullar bone was seen at 8 weeks. In histomorphometric analysis, marrow bone density increased significantly in experimental group compared to control group. Fibronectin immunoreactivity was strong at 2 weeks in experimental group and reduced after 4 weeks gradually. But it was maintained continuously from 2 to 8 weeks in control group. Collagen type I immunoreactivity was very strong from 2 to 4 week in experimental group. And the amount of Collagen type I expression was more abundant in experimental group. Conclusion: The results of this study suggest that calcium and vitamin D supplementation promote bone healing around titanium implants in osteoporosis induced animals.

• Imaging Science in Dentistry
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• v.35 no.1
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• pp.1-8
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• 2005

Purpose : To investigate the effects of irradiation on the calcium content and calcific nodule formation in the MC3T3-E1 osteoblastic cell line. Materials and Methods : Cells were irradiated with a single dose of 2,4 and 8 Gy at a dose rate of 5.38 Gy/min using a Cs-137 irradiator. After irradiation, the calcium content and calcific nodule formation were examined on the 1 st, 2nd, 3rd and 4th week. Results : A decreasing dose-dependent tendency of the cell proliferation rate was found in all irradiated groups of this experiment when compared with the unirradiated control group. In accordance with the duration of culture, there was no significant difference in the cell proliferation rate after irradiation of 2 Gy when compared with the unirradiated group, however a decreasing tendency was found in 4 Gy- and 8 Gy-irradiated groups. While an increase in total calcium content after irradiation of 2 Gy was found at week 1, week 2, and week 4, there was a decrease in calcium content at week 1 through 4 in the 8 Gy- irradiated group. Calcific nodule formation was increased in irradiated experimental groups when compared with the unirradiated control group in the 2 Gy-irradiated group, but decreased in the 4 Gy- and 8 Gy-irradiated groups at the same stage. Conclusion : The results showed a mild increasing tendency of the calcific nodule formation after irradiation of 2 Gy. However, a decreased calcific nodule formation in 4 Gy- and 8 Gy-irradiated groups was found. Taken together, the irradiation of 2 Gy mildly activated bone formation, however 4 Gy or 8 Gy suppressed bone formation by decreasing cell numbers in the MC3T3-El osteoblastic cell line.

• The Journal of Korean Academy of Prosthodontics
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• v.8 no.1
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• pp.48-55
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• 1968

1958년(年) Fullmer와 $Lillie^9$에 의(依)하여 최초(最初)로 보고(報告)된 Oxytalan 섬유(纖維)는 산(酸)에 내성(耐性)이 강(强)한 섬유(纖維)로 치근막(齒根膜)에 많이 출현(出現)하고 기계적(機械的) 자극(刺戟)에 의(依)하여 배열(配列), 주행(走行) 및 수적(數的)인 변화(變化)를 가져온다. 저자(著者)는 교정력(矯正力)을 이용(利用)하여 치아(齒牙)를 이동(移動) 시킨후(後) 치근막내(齒根膜內) Oxytalan섬유(纖維)의 수(數), 주행(走行) 및 형태(形態)의 변화(變化)를 실험적(實驗的)으로 관찰(觀察)한바 있어 이를 보고(報告)하는 바이다. 본연구(本硏究)에 사용(使用)된 실험동물(實驗動物)로는 체중(體重) 60gram내외(內外)의 자성백서(雌性白鼠) 15마리를 택(澤)하였다. 각동물(各動物)은 Ether마취후(麻醉後) 교정용(矯正用) 고무줄편(片)을 상악우측(上顎右側) 제1구치(第一臼齒)와 제2구치(第二臼齒) 사이에 삽입(揷入)하여 24, 48, 72시간(時間) 간격(間隔)으로 관찰(觀察)하였다. 동물(動物)을 도살후(屠殺後) 상악골(上顎骨)을 적출(摘出)하여 10%중성(中性) 호루마린에 고정후(固定後) 3%의산(蟻酸)으로 탈회(脫灰)하였다. 파라핀 포매후(包埋後) 근원심적(近遠心的)으로 $4{\sim}6{\mu}$의 절편(切片)을 만들어 Hematoxylin-eosin 및 Aldehyde fuchsin염색(染色)을 시행(施行)하여 경험(鏡險)한 결과(結果)는 하기(下記)와 같다. 1. 치아이동후(齒牙移動後) 교원성섬유(膠原性纖維) 및 Oxytalan섬유(纖維)들의 배열(配列)에 있어 뚜렷한 차이(差異)를 보였다. 2. 치아이동후(齒牙移動後) 사주섬유(斜走纖維)는 염박측(壓迫側)에서는 치아장축(齒牙長軸)에 수직(垂直)되게, 견인측(牽引側)에서는 평행(平行)되게 주행(走行)하고 있었다. 3. 48시간군(時間群)에서 세포증식(細胞增殖)이 심(甚)하였다. 4. Oxytalan섬유(纖維)는 치아(齒牙)들에 교정력(矯正力)을 가(加)한후(後) 견인(牽引) 염박(壓迫) 양측(兩側) 공(共)히 수(數)가 증가(增加)하였다. 5. 염박측(壓迫側)에서 Oxytalan섬유(纖維)는 속(束)을 형성(形成)하며 치아장축(齒牙長軸)에 평행(平行)되게 주행(走行)하였다. 6.견인측(牽引側)에서는 하나 또는 두세개의 섬유(纖維)들이 산발적(散發的)으로 치아장축(齒牙長軸)에 평행(平行)되게 하였다. 7. Oxytalan섬유(纖維)의 수(數)는 염박측(壓迫側)에서 보다 견인측(牽引側)에서 더 변화(變化)가 많았다.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.97-106
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• 2010

Aim of the study: An alternative source of adult stem cells that could be obtained in large quantities, under local anesthesia, with minimal discomfort would be advantageous. Adipose tissue could be processed to obtain a fibroblast-like population of cells or adipose tissue-derived stromal cells (ATSCs). This study was performed to confirm the availability of ATSCs in bone tissue engineering. Materials amp; Methods: In this study, adipose tissue-derived mesenchymal stem cell was extracted from the liposuctioned abdominal fat of 24-old human and cultivated, and the stem cell surface markers of CD 105 and SCF-R were confirmed by immunofluorescent staining. The proliferation of bone marrow mesenchymal stem cell and ATSCs were compared, and evaluated the osteogenic differentiation of ATSCs in a specific osteogenic induction medium. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific BMP-2, ALP, Cbfa-1, Osteopontin and osteocalcin were confirmed by RT-PCR. With differentiation of ATSCs, calcium concentration was assayed, and osteocalcin was evaluated by ELISA (Enzyme-linked immunosorbant assay). The bone formation by 5-week implantation of HA/TCP block loaded with bone marrow mesenchymal stem cells and ATSCs in the subcutaneous pocket of nude mouse was evaluated by histologic analysis. Results: ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. ATSCs could be easily identified through fluorescence microscopy, and bone formation in vivo was confirmed by using ATSC-loaded HA/TCP scaffold. Conclusions: The present results show that ATSCs have an ability to differentiate into osteoblasts and formed bone in vitro and in vivo. So ATSCs may be an ideal source for further experiments on stem cell biology and bone tissue engineering.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.320-329
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• 2005

The three-dimensional (3D) changes of bone, soft tissue and the ratio of soft tissue to bony movement was investigated in 8 skeletal Class III patients treated by mandibular setback surgery. CT scans of each patient at pre- and post-operative states were taken. Each scan was segmented by a threshold value and registered to a universal three-dimensional coordinate system, consisting of an FH plane, a mid-sagittal plane, and a coronal plane defined by PNS. In the study, the grid parallel to the coronal plane was proposed for the comparison of the changes. The bone or soft tissue was intersected by the projected line from each point on the gird. The coordinate values of intersected point were measured and compared between the pre- and post-operative models. The facial surface changes after setback surgery occurred not only in the mandible, but also in the mouth corner region. The soft tissue changes of the mandibular area were measured relatively by the proportional ratios to the bone changes. The ratios at the mid-sagittal plane were $77\~102\%(p<0.05)$. The ratios at all other sagittal planes had similar patterns to the mid-sagittal plane, but with decreased values. And, the changes in the maxillary region were calculated as a ratio, relative to the movement of a point representing a mandibular movement. When B point was used as a representative point, the ratios were $14\~29\%$, and when Pog was used, the ratios were $17\~37\%(9<0.05)$. In case of the 83rd point of the grid, the ratios were $11\~22\%(p<0.05)$.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.1
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• pp.63-68
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• 2006

Purpose: To assess the effectiveness of the Locking compression plate (LCP) after open reduction for the treatment of the displaced clavicular shaft fracture, the clinical and radiologic outcome of the patients who were managed with the LCP for internal fixation after open reduction has been analyzed. Materials and Methods: We reviewed 26 cases with a displaced clavicular shaft fracture treated by internal fixation using Locking compression plate after open reduction between May 2003 and November 2004. The patients were followed up for at least six months period, and final postoperative outcome was evaluated using clinical results based on Kang's criteria, radiologic signs of fusion. Results: All fractures united by an average of 9.3 weeks without delayed union and showed fast recovery of motion fraction and shoulder function. In addition,24 cases without the fractures of proximal humerus recovered to normal range of shoulder notion within 2.9 weeks. Clinically, according to Kang's criteria, the outcome was good or better in 22 patients. The complications included shoulder joint dysfunction in two cases and keloid formation in one case, and no other complications were observed. Conclusion: The internal fixation using LCP for the treatment of displaced clavicular shaft fracture is a safe, reliable method of treatment, with few complications, and offers rapid recovery of shoulder joint function and bone union.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.3
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• pp.205-217
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• 2005

Distraction osteogenesis is a technique of lengthening bone including soft tissue by gradual separation of surgically divided bone surfaces. Although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the molecular mechanisms governing the formation of new bone in distracted bone segments remain largely unclear. However, such information has significant clinical implications because it may enable targeted therapeutic manipulations designed to accelerate osseous regeneration. The purpose of this study was to evaluate the expression of TGF-$\beta$1, IGF-I and bFGF in distraction osteogenesis according to different distraction rates in a rabbit's mandible. When twenty-four adult rabbits underwent open osteotomy between the premolar and mental foramen, an external bilateral distraction device was applied. Latency was allowed for five days before distraction. Three different distraction rates were 0.7 mm/day (A, n=8), 1.4 mm/day (B, n=8) and 2.4 mm/day (C, n=8). The distraction device was activated with the same distraction rhythms of twice a day until 4.9 mm (A & B group) and 8.4 mm (C group) length gains was achieved. The animals were sacrificed at postoperative 3, 7, 14 and 28 days. The bony specimens were stained with H&E for histologic examination, and RT-PCR analysis was done for the identification of the expression of TGF-$\beta$1, IGF-I and bFGF. The results obtained from this study were as follows : The 0.7 mm/day and 1.4 mm/day distraction rate groups were shown to improve regenerative bone formation on radiographic and histologic examination. Also, TGF-$\beta$1, IGF-I and bFGF expression increased in the 0.7 mm/day and 1.4 mm/day distraction rate groups. But the 2.4 mm/day distraction rate group specimen was different with adjacent normal bone and hardly expressed of growth factors. These findings suggest that improved new bone formation in the 0.7 mm/day and 1.4 mm/day distraction rates is associated with enhanced expression of TGF-$\beta$1, IGF-I and bFGF by mechanical tension stress. Additionally, the 0.7 mm/day and 1.4 mm/day distraction rate groups were significantly different from the 2.4 mm/day distraction rate group in the expression of growth factors. According to the above results, it seems possible to apply a distraction rate of up to 1.4 mm/day a day in rabbit's mandible. And further studies are needed to evaluate growth factors of TGF-$\beta$1 and IGF-I, which are excellent in expression.

• The korean journal of orthodontics
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• v.36 no.5
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• pp.324-330
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• 2006

Objective: The purposes of this study were to evaluate the differences between sand blasted, large grit and acid-etched (SLA) treated mini-implants and smooth surface orthodontic mini-implants in relation to the removal torque as well as the histologic analysis. Methods: Custom-made, screw-shaped, titanium implants with a length of 9.5 mm and an outer diameter of 1.8 mm were divided into 2 groups; the SLA group (20 SLA treated orthodontic mini-implants) and the smooth surface group (20 smooth surface mini-implants), and placed In the tibia metaphysis of 10 rabbits. Each rabbit had 4 mini-implants placed, 2 in each tibia. The right tibia were implanted with the SLA group mini-implants and the left tibia had the smooth group mini-implants placed. Each mini-implant group were immediately applied with a continuous traction force of 150 g using a Ni-Ti coil spring. The rabbits were sacrificed 6 weeks post-surgically. Subsequently, the legs were stabilized, the Ni-Ti coil springs were removed and the mini-implants were removed under reverse torque rotation with a digital torque gauge. Results: 6 weeks after placement, the SIA group presented a higher mean removal torque value (8.29 Ncm) than the smooth group (3.34 Ncm) and histologic analysis revealed a higher new bone formation aspect along the screw in the SLA group. Conclusion: Results of this study indicates that SLA treated mini-implants may endure higher orthodontic forces without loosening.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1162-1168
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• 2000

This study was designed to determine the seafood prcference of the 480 elcmentaty school children in Pusan. The survey was conducted from February 8 to February 22 in 2000. The correlation between nutrition knowledge and dietary attitude is highly significant. However there were no differences in nutrition knowledge and dietary attitude berween male and frmale students. Children's prefercnce is high in laver, crab, common squid, mackerel, hair tail, shrimp, but is low in oyster, warty sea squirt and salt-fermented seafood. The factors affected on the intake frequcncy of seafood and preference were dietary attitude of the children, cducation level of the mother and recommendation of the mother. Children's opinion on the intake of seafood was influenced by their nutrition knowledge and dietary attitude and the recommendation of the mother. Eating frequcncies of the seafood were not influenced by sex, family type, monthly food expenditure and dietary attitude of the mother.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.71-77
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• 2010

Introduction: The purpose of this study is to evaluate the effect of platelet rich plasma in bone formation and osseointegration of implant installed in the bone marrow space. Materials and Methods: Five beagle dogs were used as experimental animals. Two implants were installed on each tibia in the dogs. Implants of the control group were installed with no additional graft. Those of the experimental group 1 were installed with autogenous bone graft from the ilium autogenous bone. Platelet rich plasma (PRP) alone was used in experimental group 2 and the mixture of PRP and autogenous bone was used in experimental group 3. The animals were sacrificed at 8 weeks after implantation. The parts of tibia containing implant were harvested and radiographs were taken for radiographic examination. The specimens were prepared for histological examination and histomorphometric analysis of implant-bone contact ratios. Results: 1. All implants showed sufficient osseointegration in the cortical bone radiographically and histologically, but osseointergration in the marrow space was not satisfactory. 2. Histomorphometrically, the implant-bone contact ratios in the bone marrow was sequentially high in the experimental group 3 (autogenous bone + PRP group), group 1 (autogenous bone group), group 2 (PRP group), and control group (non-additive). 3. It was verified that there was statistical significance between two experimental groups (group 1 and 3) and the other groups (group 2 and control group). (P<0.005) 4. However, there was no statistical significance between group 3 and group 1, also group 2 and control group respectively. Conclusion: These results suggest that platelet rich plasma is effective to osseointegration in the implant installation but there is no statistical significance.