• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권6호
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• pp.602-605
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• 2000

Human alveolar bone cells were isolated from alveolar bone fragments obtained from normal individual undergoing third molar extractions. Alveolar bone fragments were cultured as explant. Cells began to migrate in the first $5{\sim}7$ day and were confluent in $5{\sim}7$ week. Matrix mineralization was observed by 4 week. Our studies utilize established protocols for the characterization of these cells as osteoblasts by means of alkaline phosphatase activity determination, identification of osteocalcin antigens, establishing the presence of cells expressing type I collagen and determining the ability of cells to produce calcification. Transmission electron microscopic observations confirmed the presence of a collagen matrix undergoing a mineralization process. This new model, using human alveolar bone cells, may provide a tool to investigate alveolar bone development and physiology and to set up new therapeutic approaches.

• International Journal of Oral Biology
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• 제44권1호
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• pp.1-7
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• 2019

Osteoporosis is a common disease characterized by bone mass reduction, leading to an increased risk of bone fracture, and it is caused by an imbalance of osteoblastic bone formation and osteoclastic bone resorption. Current osteoporosis drugs aim to reduce the risk of bone fracture, either by increasing osteoblastic bone formation or decreasing osteoclastic bone resorption. However, osteoblasts and osteoclasts are closely coupled, such that any reagent altering the differentiation or activity of one eventually affects the other. This tight coupling between osteoblasts and osteoclasts not only limits the therapeutic efficacy but also threatens the safety of osteoporosis drugs. This review will discuss the biological mechanisms of action of currently approved medications for osteoporosis treatment, focusing on the osteoblast-osteoclast coupling.

• Journal of Oral Medicine and Pain
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• 제13권1호
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• pp.85-93
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• 1988

The author studied maximum clenching EMG activities of temporalis anterior and masseter muscle during canine guidance and centric occlusion. It was performed before and after anesthesia of maxillary and mandibular canines. The 22 normal subjects (15 males and 7 females) who had healthy maxillary and mandibular canines were selected. Their occlusal contact scheme was canine guidance during movement and they did not have temporomandibular disorder. The results were as follows : 1. The maximum clenching EMG activities of temporalis anterior and masseter muscle during guidance were less than those during centric occlusion. 2. After left maxillary and mandibular canines were anesthetized with 2% lidocanine with 1:100,000 epinephrine, the maximum clenching EMG acivities of temporalis anterior and masseter muscle during left canine guidance were greater than those before anesthesia of left maxillary and mandibular canines(p<0.01) 3. The maximum clenching EMG activities of temporalis anterior and masseter muscle during right guidance were not significantly different between before and after anesthesia of left maxillary and mandibular canines(p>0.05).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권4호
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• pp.256-263
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• 2002

Using the rat's skull, the study on the biodegradability and guided bone regeneration of the chitosan membrane was performed. The results are as follows: 1. The biodegradability of the chitosan membrane could not be confirmed, but after 12 weeks, this membrane did not yet break into small pieces and there was no specific local tissue reaction. 2. It was not certain whether the pore size of this membrane was affected on osteoblastic activity. 3. After 6 weeks, the bony defect area of rat's skull was not completely filled, but on high magnification it showed that the osteoclasts and the osteoblasts were observed in the regenerating area. In conclusion, the chitosan membrane developed in this study was fit for guided bone regeneration.

• 한국치위생학회지
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• 제15권5호
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• pp.813-821
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• 2015

Objectives: The purpose of the study was to investigate the relationship between health behavior and oral symptoms in Korean adolescents. Methods: The subjects were 72,060 adolescents who were selected from the web-based survey of the 10th (2014) Korean Youth Risk Behavior of Korean Center for Disease Control. Data were analyzed by PASW statistics 18.0. A web-based self-reported questionnaire was completed by 74,167 middle and high school students. The subjects consisted of 36,470 boy students (52.2%) and 35,590 girl students (47.8%) from 400 middle schools and 400 high schools. Results: Multiple logistic regression analysis revealed that experience of oral symptoms were related with sex, age, academic achievement, economic status, alcohol drinking, moderate physical activity, muscular strength exercises, walking, fruit consumption, milk consumption, fast food consumption, snack consumption, daily tooth brushing frequency, use of fluoride toothpaste, school based oral health education, dental sealant and dental scaling. Conclusions: There were close relationship between heath behavior, oral health behavior, and experience of oral symptoms. To improve the health promotion for the adolescents, oral health program development and primary prevention strategy must be established.

• Journal of Oral Medicine and Pain
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• 제24권2호
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• pp.137-143
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• 1999

Aucubin, the natural product, which is isolated from Aucuba japonica, has a variety of pharmacological effects such as liver-protective function, inhibition of liver RNA and protein biosynthesis, hypotensive activity and antimicrobial effect, etc. This study was performed to investigate the effects of iridoid compounds on wound healing. The author prepared 0.1% aucubin solution and 0.1% aucubin ointment as an active form, aucubigenin to which aucubin was converted by ${\beta}$-glucosidase. Artificial surgical wound was made on either 1cm lateral side of the dorsal midline along the axis of spine of Sprague-Dawley rats under sterile technique. Application of 0.1% aucubin solution or 0.1% aucubin ointment to surgical wound was done daily. Light microscopic examination was performed on the postsurgical 3 days, 5 days, and 9 days. The 0.1% aucubin solution group epithelialized earlier than the control group and the fibrosis of granulation tissue of both aucubin groups were more prominent than the control group. Collectively, this study suggests the possibility of aucubin as a topical agent. Further research should be performed on the mechanism of aucubin on wound healing and proper formulation for effective topical agents.

• Food Science and Biotechnology
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• 제14권1호
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• pp.94-98
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• 2005

Bone resorption surrounding tooth root causes tooth loss in periodontitis patients. Osteoclast has bone resorption activity. Effects of Artemisia asiatica on bone resorption induced by periodontopathogens, Porphyromonas gingivalis and Treponema denticola, were examined using co-culture systems of mouse osteoblasts and bone marrow cells. Addition of A. asiatica ethanol extract to bacterial sonicate abolished bacteria-induced osteoclastogenesis. To determine inhibitory mechanism of A. asiatica against osteoclastogenesis, effects of A. asiatica on expressions of osteoclastogenesis-inducing factors such as receptor activator of NF-${\kappa}B$ ligand (RANKL), prostaglandin $E_2\;(PGE_2)$, interleukin (IL)-1, and tumor necrosis factor (TNF)-${\alpha}$, in osteoblasts were examined. A. asiatica suppressed expressions of RANKL, $PGE_2$, IL-$1{\beta}$, and TNF-${\alpha}$ increased by each bacterial sonicate. These results suggest inhibitory action of A. asiatica against osteoclastogenesis is associated with down-regulations of RANKL, $PGE_2$ IL-$1{\beta}$, and TNF-${\alpha}$ expressions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권2호
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• pp.94-100
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• 2006

Purpose: This study was done to confirm the role of NF-$\kappa$B in cisplatin-induced apoptosis of oral squamous cell carcinoma. Materials and Methods: Five cell lines originated from different oral cancer patients were tested for the apoptosis by the treatment of cisplatin. These cells showed different degree of cisplatin-resistance and the order is OSCC-2>OSCC-3>OSCC-5> OSCC-1>OSCC-4. OSCC-2 and OSCC-4 cells were assayed for the apoptosis by measuring DNA fragmentation and TUNEL staining after cisplatin treatment. While OSCC-4 cells showed apoptosis, OSCC-2 cells showed no or very slight apoptosis by cisplatin treatment. Next, It was determined whether NF-$\kappa$B activation is required in mediating cisplatin-induced apoptosis of OSCC-4. Result: The result was that elevated NF-$\kappa$B activity mediated cisplatin-induced apoptosis. Conclusion: In conclusion, these findings suggest that NF-$\kappa$B activation is essential to cisplatin-induced apoptosis and it may be involved in cisplatin resistance in OSCC cells.

• Journal of Oral Medicine and Pain
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• 제17권1호
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• pp.41-50
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• 1992

The authors performed a experimental study to evaluate the effects of masticatory muscle fatigue on tooth contact and masticatory muscle activity in 26 normal healthy women. The experimental masticatory muscle fatigue was induced by unilateral biting of 5kg force on mandibular first molar. The results were as follows : 1. The initial symptom related to muscle fatigue pain appeared in 85.19 seconds of isometric contraction and the endurance time of isometric contraction was 203.15 seconds. 2. The pain occurred more frequently in masseter region than in temporal region. In masseter pain the incidence was almost equal between both sides, whereas the temporal pain was more in contralateral side. 3. The spontaneity and the symmetry of tooth contact during maximum clenching were reduced after isometric unilateral biting. 4. After induction of experimental muscle fatigue, the EMG activities of masseter muscles of both sides and ipsilateral temporal muscle showed the tendency of decreasing activities. 5. The asymmetry indicies of masseter and temporal muscles were reduced after isometric bilateral biting.

• International Journal of Oral Biology
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• 제43권1호
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• pp.37-42
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• 2018

It is noted that Streptococcus mutans (S. mutans) triggers dental caries establishment by two major factors: the synthesis of organic acids, which demineralize dental enamel, and the synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Therefore, it is noted that the development of a more effective, substantial and safe preventive agent that works against dental caries and periodontal disease is required at this time. For this reason, the present study was designed to investigate the effect of croton seed ethanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. In this case, the ethanol extract of croton seed showed concentration dependent inhibitory activity against the growth, acid production and adhesion of S. mutans. Especially, it is important to note that it has produced significant inhibition at the concentration of 0.1 and 0.2 mg/ml as compared to the control group. Moreover, these results suggest that the application of croton seed extract may be considered to be a useful method for the prevention of dental caries.