• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.35-44
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• 2005

Purpose: The aim of this preliminary study was to evaluate the effect of Problem-Based Learning (PBL) curriculum on development of comprehension of basic medical knowledge and quality of semi-structured problem solving including scientific reasoning skill. This scientific reasoning contained five components including: size of simple, design of research cause-effect, construction of risk factor, analysis statistic of data, interpretation of result. Materials and Methods: Seoul National University Dental students (100) participated in this experience during two weeks, 2004. Forty eight multiple-choice questions (MCQ) concerned "Infection Control and Prevention" were asked before and after two sections of Lecture-Based Learning (LBL) and PBL (pretest-posttest control group design). A semi-structured problem in epidemiological research was asked to these students after two sections (posttest-only control group design). Data (mean and SD) were analysed using the t Test for two independent samples (p<.05), comparing PBL versus LBL. Results: Our analyse of scores show no difference between LBL and PBL in the development of comprehension of "Infection Control and Prevention". The quality problem solving (epidemiological research) was significantly different between the two groups (p=.029); specially, two components' scores of reflection on scientific reasoning cause-effect (p=.000) and interpretation of result (p=.001) were significantly better for PBL than for LBL. Conclusion: Theses results indicate that comparing LBL and PBL, PBL curriculum have not been disadvantaged in comprehension of basic knowledge, and have contributed to develop the scientific reasoning in problem solving.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.288-299
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• 2003

Statement of problem: Many kinds of post and core systems are in the market, but there are no clear selection criteria for them. Purpose: The purpose of this study was to compare the flexural strength and modulus of elasticity of core materials, and measure the bending strength of post systems made of a variety of materials. Material and Methods: The flexural strength and elastic modulus of thirteen kinds core buildup materials were measured on beams of specimens of $2.0{\times}2.0{\times}24{\pm}0.1mm$. Ten specimens per group were fabricated and loaded on an lnstron testing machine at a crosshead speed of 0.25mm/min. A test span of 20 mm was used. The failure loads were recorded and flexural strength calculated with the measured dimensions. The elastic modulus was calculated from the slopes of the linear portions of the stress-stram graphs. Also nine kinds commercially available prefabricated posts made of various materials with similar nominal diameters, approximately 1.25mm, were loaded in a three-point bend test until plastic deformation or failure occurred. Ten posts per group were tested and the obtained data were anaylzed with analysis of variance and compared with the Tukey multiple comparison tests. Results: Clearfil Photo Core and Luxacore had flexural strengths approaching amalgam, but its modulus of elasticity was only about 15% of that of amalgam. The strengths of the glass ionomer and resin modified glass ionomer were very low. The heat pressed glass ceramic core had a high elastic modulus but a relatively low flexural strength approximating that of the lower strength composite resin core materials. The stainless steel, zirconia and carbon fiber post exhibited high bending strengths. The glass fiber posts displayed strengths that were approximately half of the higher strength posts. Conclusion: When moderate amounts of coronal tooth structure are to be replaced by a post and core on an anterior tooth, a prefabricated post and high strength, high elastic modulus core may be suitable. CLINICAL IMPLICATIONS In this study several newly introduced post and core systems demonstrated satisfactory physical properties. However when the higher stress situation exists with only a minimal ferrule extension remaining a cast post and core or zirconia post and pressed core are desirable.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.761-776
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• 2005

The purpose of the present study was to examine the relationship between the form of the clinical crowns in the maxillary anterior segment and the clinical feature of gingiva such as morphological characteristics and the gingival thickness. Fifty periodontally healthy subjects were clinically examined regarding the probing depth, the thickness of the free gingiva, and the width of the keratinized gingiva. From study models of the maxillary anterior region, the width at cervical third(CW) and the length(CL) of the clinical crown, the papillary height, and the gingival angle of the 6 anterior teeth were measured. Each tooth was classified into 4 groups (longnarrow, NL; narrow, N; wide, W; short-wide, WS) according to CW/CL ratio and all the data were compared between groups NL and WS using independent t-test. Stepwise multiple regression analysis was performed for each tooth region with the gingival thickness at the level of sulcus bottom, the width of keratinized gingiva, and gingival angle as the dependent variables. As the results, the NL group of the upper anterior teeth displayed, higher papilla height, and narrower keratinized gingiva, more acute gingival angle resulting in pronounced "scalloped" contour of the gingival margin, compared to the WS group. There was no significant difference between groups NL and WS with respect to probing depth and the gingival thickness. The regression analyses demonstrated that the gingival thickness in central incisors was significantly associated to the mesio-distal width and bucco-lingual width of the crown, and labial probing depth. The width of keratinized gingiva was significantly associated with labial probing depth in central incisors and with proximal probing depth and gingival angle in lateral incisors, and with labial and proximal probing depth, and gingival angle in canines. The gingival angle was significantly associated with papillary height and CW/CL ratio and additionally with proximal probing depth in central incisors, with the width of keratinized gingiva in lateral incisors, and with labial probing depth and the width of keratinized gingiva in canines. These results indicate that the form of clinical crown in upper anterior region could influence the clinical feature of gingiva and the influencing factors might be different according to the tooth region.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.152-160
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• 2011

Purpose: The aim of this study was to evaluate the volumetric change of teeth after preparation for various designs and margin locations through Micro CT analysis (Skyscan 1076: SKYSCAN, Konitch, Belgium). Materials and methods: The 36 artificial teeth were used to determine reduction volume of upper central incisor. According to the restorative design these 36 teeth were divided into 4 groups and according to the marginal location each group was divided into 3 subgroups. The volume of unprepared teeth was obtained by using Micro CT and the volume of prepared teeth was obtained in the same method. The CT scanned images before and after preparation were superimposed. Results: The volume difference was significantly increased as follows: traditional laminate veneer < full laminate veneer < all ceramic crown < metal ceramic crown. One-way ANOVA and Tukey multiple comparison analyses were used to analyze the data in this study. In each group the volume difference was significantly increased as follows: 1 mm above CEJ < CEJ < 1 mm below CEJ (P<.05). The % volume difference of all ceramic crown and metal ceramic crown was 31 - 48% and that of laminate veneer was 14 - 30%. The volume difference of the traditional laminate veneer was 1/3 of that of metal ceramic crown. The full laminate (1 mm below CEJ) and all ceramic crown (1 mm above CEJ) showed a similar volume difference. Metal ceramic crown showed 13.7% more volume difference than all ceramic crown. Conclusion: There exists the difference in volumetric change according to designs of restoration and margin locations of preparation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3934-3943
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• 2015

This study was conducted to investigate the incidence rate of metabolic syndrome, and the related factors were examined. 620 persons who had participated in both initial and second survey were selected. Initial survey was performed at the year of 2006 and second survey was performed at the year of 2010. Among them, 460 persons who didn't initially have a metabolic syndrome were selected as the final study subjects. They were classified into 2 categories; stationary normal group (352, 76.5%), and metabolic syndrome incidence group (108, 23.5%). The incidence rate of metabolic syndrome for the subjects was 25.2 per 1,000 person years. Sex, obesity, and smoking had significant effect on the incidence of metabolic syndrome. In multiple logistic regression analysis,after controlling variables, obesity index was found to be major factor in the incidence of metabolic syndrome. The risk of metabolic syndrome was increased by overweight or obesity. The strategy to control body weight should be emphasized for prevention of metabolic syndrome.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1350-1358
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• 2013

For this study, in order to understand the perception level of foot reflex therapy and clarify its related factors among customers using foot care service centers, a survey was conducted based on structured self-administered questionnaire with 181 users of three foot care service centers located in Daejeon between September 1 and October 30, 2011. The results showed that the average score in perception level of the subjects regarding foot reflex therapy was $32.19{\pm}5.32$(Score scale of the 11 items 0-44) and people with higher level of education had a significantly higher perception level(p=0.020).The perception level based on attitude and practice of foot reflex therapy was significantly higher in the group who do it "to heal illness"(p=0.034); and who "had illness" at the time when they started the therapy (p=0.030); when they used the foot massage for a longer period (p=0.000); and those in the group who would "recommend it"(p=0.004). In multiple regression analysis, among the factors that affect perception level of foot reflex massage, reason for using foot reflex therapy, health state when starting foot reflex massage, period of using foot reflex massage, and experience of recommendation to other people were selected as significant variables, with the explanatory power of 26.1%. The results suggest that perception level of foot care service users regarding foot reflex therapy are more correlated to variables that explain their attitude and practice than general characteristic variables.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.281-291
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• 1996

458 female workers working in the small and medium scaled industries in Inchon area were surveyed to study their general characteristics, health behavior, working and environmental conditions, awareness of exposure at hazardous materials, current health status, and degree of working satisfaction. Self-administered questionnaire was distributed to the female workers with the explanation by trained interviewer on the purpose of survey and the method how to answer. The results were as follows : (1) 75.5% of the respondents are living with their families and others are living in domitary or rent house for herself. Age distribution ranges from teenagers to warren in their forties. In marital status 69.0% of workers are single and 31.0% of them have ever married. 69.4% of workers are high school graduate. The size of factory is 48.3% with less than 300 workers, 42.1% with 300~500 workers. (2) Most of the workers(86.7%) are full time workers, 52% of the respondents have working experiences in other factories. More than 65% have fewer than 5 years working experience. (3) The awareness of exposure at noise was 33% of respondents, it was significantly different by skilled status. The awareness of exposure at dust, other hazardous material was each 13.3%, 12.4% of respondents. (4) 26% of them are unsatisfied with their working cognitions and 43.7% of them are unsatisfied with their welfare in occupational system unsatisfactory rate of promotion is higher in the unmarried workers(45.6%), skilled workers(47.2%), full time workers(47.4%), long term workers(50%), and awareness group of exposure hazardous material(51.3%), compared to married women workers, unskilled workers, part-time workers, short term workers and unawareness group of exposure at hazardous materials. (5) The index of working satisfaction is rated on a scale of 1 to 10 with the higher point indicating higher satisfaction. Among the selected variables, marital status, working status, the awareness of exposure at hazardous materials, were statistically significant with the index of working satisfaction. (6) By multiple regression analysis showed that the determinant factors of index of working condition were health index, the awareness of exposure at dust, the awareness of exposure other hazardous materials, marital status and working period. In conclusion, there is a significant relationship between the awareness of exposure at hazardous material the index of working satisfaction. Therefore if the workers are less exposed to the hazardous material and are educated properly they will be more satisfied with their work thus improving their health and productivity. Finally, with the result of this study, there is a great need for the development of a health promotion program and a welfare policy for small-scale factories.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1732-1741
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• 2006

Obesity is chronic disease which influenced on health severly. The causes of obesity have been known as life change, lack of excercise, genetic factor, mental and social economic factors. Especially the obesity of women increased the risk of the diseases such as DM, osteoarthritis, cardiovascular disease, breast cancer and infertility. The limitations of the widely used negative definition of health as the absence of disease and WHO's 1946 definition of health as total social, psychological and physical well-being have long been recognized (WHO 1958). The Quality of Life (QoL) includes functional ability, the degree and quality of social and community interaction, psychological well-being as somatic sensation and life satisfaction. I investigated to compare the differences between obese women (n=63), non-obese women (n=37) in clinic and general women (n=43, control) on baseline characteristics and WHO QoL-BREF. The purpose of this study is to assist the diagnosis and treatment of obesity. WHO QoL-BREF is self administered type which consisted of 26 questions. The prospective question is calculated with 5 scores by Likert's method. The results are as follows : The means of physical, psychological, social, overall and total scores of QoL were significant among BMI group (P<0.05). The score of control group (BMI < 25) was higher than other groups significantly (P<0.05). In multiple regression analysis, the variable of high school/below middle school was significant in environmental and overall domain of QoL scores (P<0.05). The variable of college/below middle school was significant in environmental, overall domain and total score of QoL scores (P<0.05). The variable of above university/below middle school was significant in physical health, environmental, overall domain and total score in QoL scores (P<0.05). The variable of Health perception (moderate/bad) was positively significant in physical health, environmental, overall domain and total score of QoL scores (P<0.05). The variable of Health perception (good/bed) was positively significant in physical health, environmental, social, overall domain and total score of QoL scores (P<0.05). The variable as BMI non-=obese women/control was negatively significant in social domain of QoL scores (P<0.05). Above the results, It suggests that the variable as BMI did't affect on the QoL in patients and control, but the variables as education and health perception affected on the QoL scores. Further study is required to conduct QoL differences between before and after treatment of obese patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2530-2534
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• 2009

This study was performed to evaluate relationship between health behaviors of local residents and stomach cancer incidence. Case-control study was carried out on 91 cases matched for age and sex with 91 controls in a general hospital in Seoul. It was surveyed using questionnaires and interview from December 20, 2008 to January 30, 2009. Major findings are as follows. First, significant negative association was observed in recreational activity ; OR for active group was 0.23, 0.41 relative to the inactive group. Secondly alcohol consumption was a significant risk factor; relative to non-drinker for drinker of more than 30 years(OR=5.17 95% Cl=1.78-19.95). Thirdly, Eating broiled food showed a positive significant association with risk for stomach cancer(OR=3.79 95% Cl=1.61-9.84) for consumption of three times more per week. As a result of multiple logistic regression analysis, income, BMI 10 years ago, recreational activity, alcohol consumption, eating broiled and salt food were associated with stomach cancer. In conclusion, the correlation of stomach cancer incidence can be found in recreational activity, alcohol consumption, eating broiled and salt food, income, and BMI 10 years ago.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.285-292
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• 2017

The purpose of this study was to investigate the relationship between the fasting blood sugar and serum lipid levels (TC, TG, HDL-C, LDL-C) and obesity indices (BMI, body fat rates, waist circumference, waist to hip ratio). The study sample consists of 1,473 manufacturing workers aged from 30 to 59 years, who underwent a health check-up at a university hospital during the period from Jan. to Dec. 2015. A data analysis was conducted to classify the subjects into the normal and abnormal groups according to their fasting blood sugar levels depending on the average values of the serum lipids and obesity indices. Multiple regression analyzes adjusted for sex and age were conducted for the factors affecting the fasting blood sugar level. As a result, the Serum TC, TG, LDL-C, BMI and waist circumference were found to be significantly higher in the abnormal fasting blood sugar level group than in the normal one, but the HDL-C was significantly lower in the abnormal group than in the normal one The fasting blood sugar level had a significant positive correlation with the TC, TG, LDL-C, BMI and waist circumference. The TC, TG, BMI and body fat were the significant factors affecting the fasting blood sugar. The above results suggest that the fasting blood sugar and serum lipid levels (TC, TG, HDL-C, LDL-C), obesity indices (BMI, body fat rates, waist circumference, waist to hip ratio) of manufacturing workers are significantly associated with each other.