• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.370-375
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• 2008

Sagittal split ramus osteotomy (SSRO) is widely used in treatment of dentofacial deformities. But, many complications can occur including unfavorable fractures during osteotomy. To prevent these complications, it is necessary to understand comprehensively the anatomy of the mandiular ramus. The purpose of this study was to evaluate the morphology of the madibular ramus in manibular prognathism patients by computed tomography comparing with normal control group. The study group consisted of 33 skeletal class III patients (20 males, 13 females) and the control group consisted of the 52 patients without dentofacial deformities (32 males, 20 females). The mean age of study group was 22.0-year old, and that of control group was 37.1-year. For the CT examination, following scan parameters was used: 1mm slice thickness, 0.5 second scan time, 120kV and 100mA/s. The axial scans of the head were made parallel to the mandibular occlusal plane. The anteroposterior length of the ramus, the distance from anterior border of the ramus to lingula, the relative distance from the anterior border of the ramus to lingula compared to the anteroposterior length of the ramus, the thickness of anterior and posterior cortical plate, the thickness of medial cortical plate of the ramus at lingula level, the thickness of cancellous bone of the ramus at lingula level were measured. The skeletal class III mandibular prognathism patients exhibited shorter anteroposterior length of the ramus, thicker anterior and posterior cortical plate, thinner mediolateral cancellous bone thickness. The lingula has a relative stable anteroposterior position in ramus in all groups. There was higher possibility of fusion of medial and lateral cortical plate at lingula level in the mandibular prognathism group. In conclusion, the mandibular prognathism patients have narrow rami with scanty cancellous bone, which means that careful preoperative examination including CT scan can prevent undesirable fractures during osteotomy.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.17.1-17.6
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• 2016

Background: The aim of this study is to verify the feasibility of using silk fibroin (SF) as a potential membrane for guided bone regeneration (GBR). Methods: Various cellular responses (i.e., cell attachment, viability, and proliferation) of osteoblast-like MG63 cells cultured on an SF membrane were quantified. After culturing on an SF membrane for 1, 5, and 7 days, the attachment and surface morphology of MG63 cells were examined by optical and scanning electron microscopy (SEM), cell viability was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell proliferation was quantified using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining. Results: Optical microscopy revealed that MG63 cells cultured on the SF membrane proliferated over the 7-day observation period. The viability of cells cultured on SF membranes (SF group) and on control surfaces (control group) increased over time (P < 0.05); however, at respective time points, cell viability was not significantly different between the two groups (P > 0.05). In contrast, cell proliferation was significantly higher in the SF membrane group than in the control group at 7 days (P < 0.05). Conclusions: These results suggest that silk fibroin is a biocompatible material that could be used as a suitable alternative barrier membrane for GBR.

• 대한기계학회논문집A
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• 제38권11호
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• pp.1273-1281
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• 2014

조직공학은 손상된 골 조직 및 장기를 복원, 재생, 그리고 복구할 수 있는 잠재력을 가진 새로운 학문 분야이다. 인산칼슘계 세라믹스인 삼인산칼슘과 수산회인회석은 골 조직 재생을 위해 골전도성과 생체적합성의 특성을 가진 우수한 재료로 알려져 있다. 본 연구에서, 혼합 용액 구조물은 적층 및 히터장치를 기반으로 한 압출 적층 조형 시스템을 이용하여 제작되었다. 바이오 세라믹 인공지지체는 $1,300^{\circ}C$의 고온에서 소결되었고, 또한 형태학적인 특성은 주사전자현미경을 통해 분석되었다. 게다가, TCP/HA 의 혼합비율에 따른 미세구조물과 수축률에 대한 효과는 연구되었다. 인공지지체의 기계적 특성은 1 mm/min 의 크로스헤드 속도로 압축 시험기를 통해 측정되었고, 인공지지체의 세포 증식평가를 위해 MG-63 세포를 이용하였다. 본 연구의 결과는 혼합된 TCP(75 wt%)/HA(25 wt%) 인공지지체가 골 조직 재생을 위해 적합한 인공지지체라는 것을 제안한다.

• Journal of Periodontal and Implant Science
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• 제42권4호
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• pp.127-135
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• 2012

Purpose: The aim of this study was to compare the clinical outcome of open flap debridement (OFD) with a biphasic calcium phosphate (BCP) graft to that of OFD without BCP graft for the treatment of intrabony periodontal defects (IBDs). Methods: The study included 25 subjects that had at least one intrabony defect of 2- or 3-wall morphology and an intrabony component ${\geq}4$ mm as detected radiographically. Subjects were randomly assigned to treatment with (BCP group, n=14) or without BCP (OFD group, n=11). Clinical parameters were recorded at baseline and 6 months after surgery and included the plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC). A stringent plaque control regimen was enforced for all of the patients during the 6-month observation period. Results: In all of the treatment groups, significant PD reductions and CAL gains occurred during the study period (P<0.01). At 6 months, patients in the BCP group exhibited a mean PD reduction of $3.7{\pm}1.2$ mm and a mean CAL gain of $3.0{\pm}1.1$ mm compared to the baseline. Corresponding values for the patients treated with OFD were $2.5{\pm}0.8$ mm and $1.4{\pm}1.0$ mm, respectively. Compared to OFD group, the additional CAL gain was significantly greater in the patients in BCP group (P=0.028). The additional PD reduction was significant for the BCP group (P=0.048). The REC showed a significant increase in both groups, and the amount of recession was significantly smaller in the BCP group than OFD group (P=0.023). In radiographic evaluation, the height of the bone fill in the BCP group was significantly greater than OFD group. Conclusions: The clinical benefits of BCP found in this study indicate that BCP may be an appropriate alternative to conventional graft materials.

• Imaging Science in Dentistry
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• 제39권1호
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• pp.41-49
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• 2009

Purpose: To detect the progression of experimentally induced periapical lesions on periapical radiograph and cone beam computed tomograph (CBCT) by quantitative analysis. Materials and Methods: After the removal of coronal pulps from premolars of two Beagle dogs, the root canals of premolars were exposed to oral environment during one week and then sealed for 70 days. Digital periapical radiographs and CBCTs were taken at baseline and every 7 days for 77 days after pulp exposure. We examined occurrence and areas of periapical bone resorption. Three comparative groups of CBCT radiographs were prepared by average projection of thin slabs with different bucco-lingual thicknesses (0.1, 3.0, and 8.0 mm) using a 3D visualization software. Radiographic densities were compensated by image normalization. Digital images were processed with mathematical morphology operations. The radiographic density and morphological features of periapical lesions were compared among three groups of CBCT in different time points. Results: In the CBCT group with 0.1 mm thickness, radiographic density (p<0.05) and trabecular bone area (p<0.01) were significantly decreased at the fifth week. However, in the CBCT groups with 3 mm and 8 mm thickness and periapical radiographs, none of densitometric and morphological features showed any significant differences in different time points. Radiographic density of periapical lesion showed increasing tendency at the eleventh week after pulp exposure. Conclusion: Radiographic detection of periapical lesions was possible at the fifth week after pulp contamination by quantitative method and was affected by buccolingual bone thickness.

• Molecules and Cells
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• 제37권9호
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• pp.650-655
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• 2014

Mesenchymal stem cells (MSCs) can differentiate into neural cells to treat nervous system diseases. Magnetic resonance is an ideal means for cell tracking through labeling cells with superparamagnetic iron oxide (SPIO). However, no studies have described the neural differentiation ability of SPIO-labeled MSCs, which is the foundation for cell therapy and cell tracking in vivo. Our results showed that bone marrow-derived mesenchymal stem cells (BM-MSCs) labeled in vitro with SPIO can be induced into neural-like cells without affecting the viability and labeling efficiency. The cellular uptake of SPIO was maintained after labeled BM-MSCs differentiated into neural-like cells, which were the basis for transplanted cells that can be dynamically and non-invasively tracked in vivo by MRI. Moreover, the SPIO-labeled induced neural-like cells showed neural cell morphology and expressed related markers such as NSE, MAP-2. Furthermore, whole-cell patch clamp recording demonstrated that these neural-like cells exhibited electrophysiological properties of neurons. More importantly, there was no significant difference in the cellular viability and $[Ca^{2+}]_i$ between the induced labeled and unlabeled neural-like cells. In this study, we show for the first time that SPIO-labeled MSCs retained their differentiation capacity and could differentiate into neural-like cells with high cell viability and a good cellular state in vitro.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권2호
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• pp.91-99
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• 2012

Purpose: The purpose of this study was to evaluate the expression of osteogenic genes associated with bone regeneration on anodizing titanium surface. Methods: $20{\times}20{\times}1$ (mm) commercially pure titanium plate was made, one group was pure titanium, second group was punched, and last group was punched and anodized by electrochemical method. Through the osteogenic cell culture model, the expression of extracellular matrix proteins, such as bone morphogenetic protein-2, bone sialoprotein, aggrecan, osteocalcin, Alkaline phosphatase, collagen I had been evaluated by Real-time polymerase chain reaction, and the morphology of growing cells was evaluated by scanning electron microscopy. Results: The attachment of mesenchymal stem cell was even and well-oriented on all Ti surfaces. The osteogene expression was increased on punching groups but, decreased on anodizing surfaces in 3 week samples. Conclusion: Punched anodizing Ti has possibility be using as a dental implant material, but further in vivo study would be needed.

• Journal of Acupuncture Research
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• 제22권2호
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• pp.191-201
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• 2005

Background & Objective: Articular cartilage is a potential target for drugs designed to inhibit the activity of matrix metalloproteinases (MMPs) to stop or slow the destruction of the proteoglycan and collagen in the cartilage extracellular matrix. The purpose of this study was to investigate the effects of Aralia cordata Thunb. in inhibiting the release of glycosaminoglycan (GAG), the degradation of collagen, and MMP activity in rabbit articular cartilage explants. Methods : The cartilage-protective effects of Aralia cordata Thunb. were evaluated by using glycosaminoglycan degradation assay, collagen degradation assay, colorimetric analysis of MMP activity, measurement of lactate dehydrogenase activity and histological analysis in rabbit cartilage explants culture. Results : Interleukin-la (IL-1a) rapidly induced GAG, but collagen was much less readily released from cartilage explants. Aralia cordata Thunb. significantly inhibited GAG and collagen release in a concentration-dependent manner. Aralia cordata Thunb. dose-dependently inhibited MMP-3 and MMP-13 expression and activities from IL-1a-treated cartilage explants cultures when tested at concentrations ranging from 0.02 to 0.2 mg/ml. Aralia cordata Thunb. had no harmful effect on chondrocytes viability or cartilage morphology in cartilage explants. Histological analysis indicated that Aralia cordata Thunb. reduced the degradation of the cartilage matrix compared with that of IL -1a-treated cartilage explants.

• Molecules and Cells
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• 제38권1호
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• pp.89-94
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• 2015

The shape and activity of mitochondria are tightly regulated by fusion and fission processes that are essential for maintaining normal cellular function. However, little is known about the involvement of mitochondrial dynamics in the development of the immune system. In this study, we demonstrate that mitochondrial dynamics play a role in the differentiation and migration of immature dendritic cells (imDCs). We show that mitochondrial elongation is induced during GM-CSF-stimulated differentiation of bone marrow progenitors to imDCs accompanied by upregulation of mitochondrial fusion proteins. These processes precede the changes in mitochondrial morphology and connectivity that occur during differentiation. Mfn2 and OPA1, but not Mfn1, are transcriptionally upregulated during differentiation; however, knockdown of Mfn2 and OPA1 does not induce any change in expression of CD11c, CDC80, or CD86. Notably, knockdown of Mfn2 or OPA1 by siRNA in imDCs significantly reduces CCR7 expression and CCL19-mediated migration. These results suggest that the mitochondrial fusion-related proteins Mfn2 and OPA1 are upregulated during bone marrow progenitor differentiation and promote the migration of imDCs by regulating the expression of CCR7.

• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.61-70
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• 2022

Natural and synthetic forms of calcium phosphate cement (CPC) have been widely used in bone repair and augmentation. The major challenge of injectable CPC is to deliver the cells without cell death in order to regenerate new bone. The study objective was to investigate for the potential of stem cell-laden gelatin fibers containing injectable, nanocrystalline CPC to function as a delivery system. Gelatin noddle fiber method was developed to delivered cells into nCPC. Experimental groups were prepared by mixing cells with nCPC, mixing cell-laden gelatin fibers with nCPC and mixing cell-laden gelatin fibers containing BMP-2 with nCPC. Media diffusion test was conducted after dissolving the gelatin fibers. SEM examined the generated channels and delivered cell morphology. Fibers mixed with nCPC showed physical setting and hardening within 20 min after injection and showed good shape maintenances. The gelatin fibers mixed nCPC group had several vacant channels generated from the dissolved gelatin. Particularly, proliferation and attachment of the cells were observed inside of the channels. While live cells were not observed in the cell mixed nCPC group, cells delivered with the gelatin fibers into the nCPC showed good viability and increased DNA content with culture. Cell-laden gelatin fiber was a novel method for cell delivery into nCPC without cell damages. Results also indicated the osteogenic differentiation of gelatin fiber delivered cells. We suggest that the cell-laden gelatin fibers mixed with nCPC can be used as an injectable cell delivery vehicle and the addition of BMP-2 to enhances osteogenesis.