• Biomedical Science Letters
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• v.23 no.3
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• pp.175-184
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• 2017

Cholera toxin (CT) is an ADP-ribosylating bacterial exotoxin that has been used as an adjuvant in animal studies of oral immunization. The mechanisms of mucosal immunogenicity and adjuvanticity of CT remain to be established. In this study, we investigated the role of indoleamine 2,3-dioxygenase (IDO), which participates in the induction of immune tolerance, in CT-mediated breakdown of oral tolerance. When IDO-deficient ($IDO^{-/-}$) mice and their littermates were given oral ovalbumin, significant changes in antibody responses, footpad swelling and $CD4^+$ T cell proliferation were not observed in $IDO^{-/-}$ mice. Feeding of CT decreased IDO expression in mesenteric lymph nodes (MLN) and Peyer's patch (PP). CT-induced downregulation of IDO expression was reversed by inhibitors of nuclear factor-kappa B (NF-${\kappa}B$), pyrrolidine dithiocarbamate and p50 small interfering RNA. IDO expression was downregulated by the NF-${\kappa}B$ inducers lipopolysaccharide and tumor necrosis factor-${\alpha}$. CT dampened IDO activity and mRNA expression in dendritic cells from MLN and PP. These data indicate that CT disrupts oral tolerance by activating NF-${\kappa}B$, which in turn downregulates IDO expression. This study betters the understanding of the molecular mechanism underlying CT-mediated abrogation of oral tolerance.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.5
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• pp.240-245
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• 2014

Angiokeratoma is a benign cutaneous lesion of the capillaries, presenting as dilated vessels in the upper part of the dermis. Although this disorder is classified into various types and has been occasionally reported in the skin of the scrotum or extremities, the involvement of the oral cavity mucosa has been rarely reported. The present study reports a case of angiokeratoma circumscriptum in the buccal mucosa. The expression of vascular endothelial growth factor (VEGF) and both of its receptors (VEGFR-1 and VEGFR-2) was demonstrated by immunohistochemistry in the endothelial cells lining the dilated vessels. The expression of VEGFR-2 was higher than that of VEGFR-1 in the endothelial cells in the lesion, indicating an increased rate of endothelial cell proliferation within the lesion. Interestingly, some of the endothelial cells co-expressed VEGF and its two receptors. These results suggest that endothelial cells in the pathologically dilated vessels possess VEGF autocrine growth activity involved in vasculogenesis and maintenance in angiokeratoma lesions. To our knowledge, this is the second report published on isolated oral angiokeratoma confined to the buccal mucosa and the first case report on angiokeratoma circumscriptum involving the buccal mucosa.

• Journal of Technologic Dentistry
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• v.42 no.3
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• pp.254-261
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• 2020

Purpose: This study aimed to investigate the effect of stress and oral parafunctional habits on temporomandibular joint disorders (TMD) in college students. Methods: An online survey comprising 354 questionnaires was conducted from May 23, 2020, to June 21, 2020. The collected data were analyzed using Student's t-test, one-way analysis of variance, correlation tests, and multiple regression analysis. Results: The stress symptom score was higher in females than in males. The symptoms of physical stress were significantly higher among students from the Department of Public Health, whereas those of psychological stress were higher among students from the Department of Physical Education. Both TMDs and oral parafunctional habits were higher among females, students of the Departments of Arts and Physical Education, and seniors. The higher the stress symptom level, the higher the scores for TMD and oral parafunctional habits. TMD and oral parafunctional habits were found to be most affected by physical stress. Conclusion: These findings indicate that a reduction in physical stress is required to decrease the prevalence of oral parafunctional habits and TMDs among college students. This can be achieved by the incorporation of physical activity programs, which may aid in reducing the symptoms of physical stress.

• International Journal of Oral Biology
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• v.43 no.3
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• pp.123-127
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• 2018

Polyphenon 60 refers to the mixture of catechins present in green tea. The aim of this study was to investigate the antimicrobial activities of polyphenon 60 against 4 strains of Streptococcus mutans and 2 strains of Streptococcus sorbrinus, which are the major causative bacteria of dental caries. The minimum bactericidal concentration (MBC) values of polyphenon 60 for S. mutans and S. sobrinus were determined and the effect of biofilm formation inhibition of that was evaluated. The MBC value of polyphenon 60 against the bacterial strains was 2.5 mg/ml except for one particular strain, S. mutans KCOM 1128 for which the value was 1.25 mg/ml. The results of biofilm formation inhibition assay revealed that polyphenon 60 inhibited biofilm formation more than 90% at a concentration of 2.5 mg/ml. It was apparent that polyphenon exhibited biofilm formation inhibition activity along with bactericidal effect against S. mutans and S. sobrinus. Therefore, it is proposed that polyphenon 60 as one of the components of bactericidal agents could be useful in developing oral hygiene products, toothpaste or gargling solution.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.567-573
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• 2021

Objectives: This study aimed to determine the association between the oral health behavior of adolescents, symptoms of awareness and subjective happiness. Methods: This study is the 16th (2020) primitive self-administered survey that is completed using data on youth health behavior 54,948 to finally select people. Acomposite sample analysis was performed using SPSS window program 21.0. A chi-square test was performed tocompare subjective happiness according to the general characteristics of the subjects, oral health behavior, and awareness symptoms. Logistic regression analysis of the subjective happiness factor was the impact on composite samples. Results: Oral health is a subjective factor that affects happiness. Happiness was found to be 1.479 times higher when participants brushed their teeth more than three times a day and 1.175 times higher when they brushed after lunch. However, subjective happiness was 0.901 times lower when the awareness symptoms of pain was experienced, 0.843 times lower when there was tingling and throbbing, and 0.841 times lower when there was gingival pain. Conclusions: It is necessary to develop and guide various activity programs so that youth oral health education and subjective feelings of happiness can be improved to promote oral health.

• Journal of Oral Medicine and Pain
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• v.46 no.3
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• pp.69-74
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• 2021

As for temporomandibular joint arthritis (TMJ OA), managing the contributing factors at an early stage through accurate diagnosis is necessary to prevent irreversible bone changes. TMJ OA, which is a multi-organ disease caused by various pathophysiological mechanisms, is developed mainly due to mechanical overload. It is a disease characterized by degeneration of articular cartilage and subchondral bone as a low-level inflammatory arthritis condition developed by dysregulation of catabolic and anabolic activity of chondrocytes. Age, mechanical overload sensing of cartilage, chondrocyte apoptosis, catabolic enzymes, inflammatory factors, abnormal remodeling of subchondral bone, and estrogens may be involved in the pathogenesis of arthritis. Therefore, a comprehensive evaluation is needed to diagnose and manage progressive cartilage degeneration, subchondral bone remodeling, and associated symptoms of TMJ OA.

• International Journal of Oral Biology
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• v.47 no.4
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• pp.55-62
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• 2022

Bioactive flavonoids have been shown to improve the biological activity of stem cells derived from different sources in tissue regeneration. The goal of this study was to see how naringin, a natural flavonoid discovered in citrus fruits, affected the biological properties of human dental pulp stem cells (HDPSCs). In this study, we found that naringin increases the migratory ability of HDPSCs. Naringin increased matrix metalloproteinase-2 (MMP-2) and C-X-C chemokine receptor type 4 (CXCR4) mRNA and protein expression in HDPSCs. ARP100, a selective MMP-2 inhibitor, and AMD3100, a CXCR4 antagonist, both inhibited the naringin-induced migration of HDPSCs. Furthermore, naringin increased osteogenic differentiation of HDPSCs and the expression of the osteogenic-related marker, alkaline phosphatase in HDPSCs. Taken together, our findings suggest that naringin may be beneficial on dental tissue or bone regeneration by increasing the biological activities of HDPSCs.

• Journal of Korean society of Dental Hygiene
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• v.22 no.5
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• pp.355-363
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• 2022

Objectives: This study aimed to assess the relationship between oral symptoms and changes in daily life after coronavirus disease (COVID-19) in middle and high school students. Methods: Data were obtained from the 17th Korea Youth Risk Behavior Survey (2021). The subjects comprised 53,868 people who responded to survey questions related to this study. Multiple logistic regression analysis with complex samples was performed to identify the correlation between daily life changes and oral symptoms. Results: The analysis showed that compared to the group without changes in daily life after COVID-19, changes in daily life, such as skipping breakfast, drinking, and smoking, either decreased or increased. Furthermore, increase in depression and decreased physical activity and family economic status were related to oral symptoms. Conclusions: It is necessary to develop oral health programs for adolescents suitable for changing situations after COVID-19.

• Journal of Korean society of Dental Hygiene
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• v.24 no.3
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• pp.253-262
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• 2024

Objectives: This study aimed to identify the factors influencing the relationship between diabetes and oral health in Korean adults. Methods: We analyzed 5,319 adults who were included in the 9th Korea National Health and Nutrition Examination Survey. The data were analyzed for demographic characteristics, daily health care, and oral health care according to diabetic conditions using a complex sample analysis. Multiple logistic regression analysis was performed to analyze the factors influencing the oral health of patients with diabetes. Results: The factors influencing the oral health of patients with diabetes varied according to life cycle. In late middle-aged adults, statistically significant differences were observed in sex (p<0.001), educational level (p=0.030), economic activity (p=0.018), aerobic exercise (p=0.034), smoking (p=0.004), periodontal therapy (p=0.011), and prosthesis production/repair (p=0.025). In younger elderly individuals, statistically significant differences were found in terms of whether they lived together (p=0.027) and educational level (p=0.032). Conversely, no statistically significant differences were observed in the older elderly group. Conclusions: The results of this study showed that the level of oral health of patients with diabetes is already determined in middle and old age; therefore, a system should be prepared to ensure that health care can be systematically performed in late middle-aged adults.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.289-294
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• 2010

Salvia miltiorrhiza Bunge (S. miltiorrhiza) is a traditional Korean medicine that is commonly used for the treatment of inflammatory diseases such as edema, arthritis, and hepatitis. The present study investigated the antimicrobial activity of methanol (MeOH) extract of S. miltiorrhiza roots against oral bacteria using broth the microdilution method and the checkerboard and time-kill methods evaluated the synergistic effects of treatment with antibiotics. The MeOH extract was demonstrated as a higher antibacterial activity (MICs, 8 to $64\;{\mu}g/mL$; MBCs, 16 to $64\;{\mu}g/mL$) against all tested oral bacteria. Additionally, the extract was observed to have a synergistic effect with ampicillin or gentamicin. A time-kill study evaluating the effects of the extract indicated that the extract treatment in combination with ampicillin or gentamicin showed rapid bactericidal activity. The results suggest that MeOH extract of S. miltiorrhiza could be employed as a natural antibacterial agent against dental caries.