• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.234-238
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• 2016

Purpose: Increasing use of computer aided design-computer aided manufacturing (CAD-CAM) system and number of design software made design of restoration easy and quick. Outcome of restoration has been dependent on dental technician's wax up proficiency, dentists can design restoration for themselves now. This study aims to investigate the outcome of restoration designs, according to handling skill of CAD-CAM design tool. Materials and methods: A patient's mandibular right 1st molar was prepared. After taking impression, stone model was made, scanned the stone model with 3 shape intra-oral scanner, stereolithography (STL) file was extracted. With 3shape dental designer, one dental technician with more than 5 years work experience (designer 0) and three dental technicians with less than 2years work experience (designer 1, 2, 3-group DT) and 4 1st year residents (designer 4, 5, 6, 7-group RT) designed gold crown on the same STL file. Designed crown's MD (mesio-distal) and BL (bucco-lingual) diameter, height of crown, inter-cuspal distance, number of occlusal contact points were compared. Statistical analysis was carried out, test of normality within each group, using independent t-test. Number of contact points were compared, using Wilcoxon signed-rank test. Results: There was no significant difference between group DT and group RT. Number of contact points also resulted in no significant difference. Conclusion: The outcome of each designed crowns showed no statistical differences, in values which can be expressed as numbers. Subjective factors were different. With increasing proficiency in handling designing software, fabrication of restorations according to each designer's occlusal concept can be made easy.

• The korean journal of orthodontics
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• v.38 no.3
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• pp.202-213
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• 2008

Objective: The purpose of this study was to compare the cephalometric measurements of obese and non-obese Korean male patients with obstructive sleep apnea syndrome (OSA). Methods: Eighty-seven adults who had visited the Sleep Disorder Clinic Center in Keimyung University, Daegu, Korea were examined and evaluated with polysomnography (PSG) and lateral cephalogram. They were divided into 4 groups (non-obese simple snorers, obese simple snorers, non-obese OSA patients, obese OSA patients) according to AHI (Apnea-Hypopnea Index) and BMI (Body Mass Index). Results: The obese OSA group had the highest AHI among the 4 groups. The non-obese OSA group had a significantly steeper mandibular angle and shorter tongue length than the obese OSA group. The hyoid bone of the obese OSA group was positioned anterior and inferior as compared with the non-obese OSA group. Multiple regression analysis showed that tongue length in the obese OSA group and retroposition of hyoid bone in the non-obese OSA group were significant determinants for the severity of AHI. Conclusions: From a cephalometric point of view, the obese and non-obese pateints with OSA may be characterized by different pathogeneses. Therefore, they have to be managed by individualized treatment. For the obese OSA patients, weight control must be advised as a first choice and for the non-obese OSA patients, oral appliance, nasal CPAP, UPPP and others could be chosen according to the obstructive sites.

• Korean Journal of Community Nutrition
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• v.10 no.5
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• pp.654-667
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• 2005

To survey the different view points about food service programs among parents and teachers, 2 types of questionnaires, which consisted of attitude, perception, satisfaction and demand of the food service program in child education centers, were used. The data was collected from 2450 parents and 450 teachers who attended a child education center in 16 provinces, nationwide. SPSS was used for descriptive analysis and ANOVA test and $X^2-test$. The frinding results were as follows. 1. The average serving size of meal (lunch) were 80 meals per day and 167 meals per day at large institutions. Mean cost of snacks was 14,709 won per month and mean costs of lunch were 29,319 won per month. The mean price was not significantly different according to the scale of institution. The numbers of servings of lunch, morning snack and afternoon snack were 5, 3.4 and 3.5 times per week each. $56.4\%$ of the institutions served meals to children in classrooms, but the national/public institutions, which were attending elementary school, served meals in a dining place in the elementary school. 2. Teacher controlled serving portion size of snacks $(79.6\%)$ and lunch $(88.8\%)\;and\;30.1\%$ of teacher did not allow leaving lunch food. The ratio of knowing about preserved meals of the teacher who worked at a small institution was significantly higher than the teacher who worked at large institutions (p<0.01). 3. Between parents and teachers, several different view points about school lunch programs were detected. Most parents and teachers wanted that the school lunch to be fully cooked and served at the child education institution itself, but $12.2\%$ of parents and $14.4\%$ of teachers wanted a catering service. The teachers group preferred 'lunch box from home' and 'home partially prepared lunch' as an ideal meal serving type than the parent groups (p<0.01). And there were significantly different view points about price factors in school meals, teachers group highly answered that operating expenses must be added in meal prices. 4. The teacher groups' priorities of education activities during meal time were a significantly lower score than parents group in overall education activities. Teacher and parent groups pointed out that individual sanitation activities were most important of the education activities during meal time, but promoting good eating habits was the lowest score in both groups. 5. 'Improving taste and food quality' was most urgent in food service at child education centers, but there were significantly different view points between parent groups $(64.5\%)$ and teacher groups $(43.8\%)\;(p<0.05)$. They answered at a lower percent in 'employee qualified person' and 'cost control' point to improve food service, but there were also different opinions between the two groups (p<0.01). 6. As to the matter of the advantages and disadvantages of catering services, two group answered that the advantages of a catering service were 'convenience' and 'to solve facilities and labor problems', disadvantages were 'lower in food freshness' and 'sanitation problems'. There were also several different view pionts in catering services, the parents groups were more anxious about food sanitation than teachers. This study found several different view points about school food services among parents and teachers. To improve food services at child education institutions, there is a need to adjust the differences between the two groups through interactive communication channels and education and to employ dietitians as taking charge of adjusting roles between the two groups.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.564-578
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• 1998

Most extended care facilities have admitted both the healthy and unhealthy elderly, among which members' average caring demand vary. The Aged Welfare Law, however, currently provides no reasonable basis on the staffing policy for extended care facilities. It just reflects the admitted number of the elderly rather than differences in members' average caring demand among facilities. This study is designed to estimate the need for caring staff on the basis of the correlation between the individual health status measured by various tools including Activities of Daily Living and caring demand by actual service time for each one. The sample included all of the admitted elderly(187 persons) in 4 extended care facilities, two in Seoul and the other two in Kangwon-Do over the survey period October 5 through October 20, 1996. The survey process consisted of 3 stages. (1) The current staffing information was collected through self-completed written questionnaires left for head of official in each facility. (2) Six graduate students at School of Public Health interviewed all residents to collect information on their health status and sociodemographics. The response rate for the interview was relatively high(85%). (3) Information on direct and indirect caring time consumed for each residents came from self-completed written questionnaires given to nurses and helpers in each target facilities. Analysis of the data was made using Pearson's correlation and multiple regression technique through SAS program. Based on this procedure, the following was found. 1. No facility meet the staffing standard in the Aged Welfare Law completely. 2. It is actual service time that is most correlated with ADL(Activities of daily living). 3. When all of the elderly are divided by four groups based on the level of ADL, the mean values of needed caring time in each group are 15, 21, 36 and 88 minutes respectively. 4. There is no significant difference among facilities in distribution of elderly person by group. 5. No facility meets the estimated number of nurses and helpers which reflects health status of the admitted elderly. Therefore, it is required that severity of the admitted elderly be considered in establishing staffing standard for extended care facility.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.488-505
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• 2007

The purposes of this research are twofold; 1) to verify spatial differences of tectonic movement using the spatial distribution of earthquakes, and 2) to infer mechanisms that generate spatial accumulation patterns of earthquakes in the Korean Peninsula. The first part of this sequential paper (Park, 2007) argues that the Korean Peninsula consists of four geostructural regions in which tectonic deformation and consequent geomorphological development patterns are different from each other Since this conclusion has been made by terrain analyses alone, it is necessary to verify this suggestion using other independent geophysical data. Because earthquakes are results of movement and deformation of land masses moving in different directions, the distribution of earthquake epicenters may be used to identify the direction and rates of land mass movement. This paper first analysed the spatial distribution of earthquakes using spatial statistics, and then results were compared with the spatial arrangement of geostructural regions. The spatial distribution of earthquakes in the Korean Peninsula can be summarized as the followings; firstly, the intensity of earthquakes shows only weak spatial dependency, and shows large difference even at adjacent regions. Secondly, the epicenter distribution has a clear spatial accumulation pattern, even though the intensity of earthquake shows a random pattern. Thirdly, the high density area of earthquakes shows a clear 'L' shape, passing through Pyeongannam-do, centered at Pyeongyang, and Hwanghae-do, Seosan and Pohang. The correlation coefficient between the density of earthquakes and distance from geostructral region boundaries is much higher than those between the density of fault lines and distance from tectonic division boundaries. Since fault lines and tectonic divisions in the Korean Peninsula are the results of long-term geological development, there is an apparent scale discrepancy to find significant correlations with earthquakes. This result verifies the research hypothesis that the Korean Peninsula is divided into four geostructral regions in which each has its own moving direction and spatial deformation characteristics. The existence of geostructural regions is also supported by the movement parrerns of land masses estimated from the GPS measurements. This conclusion is expected to provide a new perspective to understand the geomorphological developments and the earthquake occurrences in the Korean Peninsula.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.199-207
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• 2013

Purpose: The importance of occlusal contacts of the natural dentition for durability of teeth, mandibular stabilization, and restorative dentistry is well known. The purpose of this study is to analyze the occlusal contact and guidance pattern of Koreans by evaluating the static occlusion on maximal intercuspal position and measuring dynamic occlusion during straight protrusion. Materials and methods: The occlusal contacts at maximal interincisal position and the occlusal guidance pattern during straight protrusion of 29 subjects were recorded with shimstock foil (Whaledent, Langenau, Germany), T-Scan III (Tekscan Inc., Boston, MA, USA), polyvinylsiloxane registration material (Genie Bite, Sultan Healthcare, Hackensack, NJ, USA) and compared. Occlusal registration procedures were repeated 3 times. The position was fixed to an upright position and the head position was fixed with the Frankfurt horizontal plane paralleling the horizontal plane. Fisher's Exact Test (R-General Public License, ver. 2.14.1) and Pearson's Test were used to assess the significance level of the differences between the experimental groups (${\alpha}=.05$). Results: When using shimstock foil, T-Scan III system, and polyvinylsiloxane registration material, most of the patients showed contact on anterior, premolar, and molar teeth during maximal intercuspal position. Approximately 51% of maximal intercuspal position showed anterior contact using shimstock foil. When examining the protrusive movement using shimstock foil and T-Scan III system, guidance pattern with the central incisor was the most common. Conclusion: During maximal intercuspal position, there were cases in which not all of the teeth showed occlusal contact. During mandibular protrusive movements, one or more maxillary central incisors frequently joined in straight protrusion and the posterior teeth were disoccluded. Therefore, the anterior teeth protect the posterior teeth, and vice versa. Thus, mutually protected occlusion should be applied when reconstructing occlusion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.442-448
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• 2016

This study was conducted to determine the appropriateness of systemic radiation exposure control for students in clinical practice by comparing radiation exposure in radiography employees at different stations of a hospital with that of students conducting clinical practice using identical stations. Overall, 121 students who conducted clinical practice in the department of radiology area of C university hospital from July 2014 to August 2014 and 62 workers working in the same medical facility (47 in the department of radiology, 8 in the department of radiation oncology, 7 in the department of nuclear medicine) were investigated. The radiation exposure experienced by students was measured for 8 weeks, which is the duration of the clinical practice. Additionally, radiation exposure of workers were classified into 4 groups, department of radiology, department of radiation oncology, and department of nuclear medicine was compared. Dose was measured with OSLD and differences among groups were identified by ANOVA followed by Duncan's multiple range test. Among employees, those in the department of radiology, oncology and nuclear medicine were exposed depth doses of $0.127{\pm}0.331mSv$, $0.01{\pm}0.003mSv$, and $0.431{\pm}0.205mSv$, respectively, while students were exposed to $0.143{\pm}0.136mSv$. Additionally, workers in the department of radiology, oncology and nuclear medicine were exposed to surface doses of $0.131{\pm}0.331mSv$, $0.009{\pm}0.003mSv$, and $0.445{\pm}0.198mSv$, respectively, while students were exposed to $0.151{\pm}0.14mSv$, which was significantly different in both doses (p < 0.01). The average dose that students received is higher than that of the other groups (except for nuclear medicine workers), indicating that further improvements must be made in systemic controls for individual radiation exposure by including the students as subjects of management for protection from radiation.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.354-361
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• 2008

Purpose: N-13 ammonia uptake and retention in the myocardium is related to perfusion and metabolism. There are several potential advantages of N-13 ammonia positron emission tomography (PET) to detect myocardial ischemia, such as higher spatial resolution, greater counting efficiencies, and robust attenuation correction. But there are few reports comparing Tc-99m myocardial perfusion single photon emission tomography (MPS) and N-13 ammonia PET. We thus compared adenosine stress N-13 ammonia PET/CT and Tc-99m sestamibi MPS in patients with suspected coronary artery stenosis. Materials and Methods: Seventeen patients (male 13 : $63{\pm}11$ years old) underwent adenosine stress N-13 ammonia PET/CT (Discovery ST, GE), Tc-99m sestamibi MPS (dual head gamma camera, Hawkeye, GE) and coronary angiography within 1 week. N-13 ammonia PET/CT and Tc-99m sestamibi MPS images were assessed with a 20-segment model by visual interpretation and quantitative analysis using automatic quantitative software (Myovation, GE). Results: Both sensitivities and specificities of detecting an individual coronary artery stenosis were higher for N-13 ammonia PET/CT than Tc-99m sestamibi MPS (PET/CT: 91%/89% vs MPS: 65%/82%). N-13 ammonia PET/CT showed reversibility in 52% of segments that were considered non-reversibile by Tc-99m sestamibi MPS. In the 110 myocardial segments supplied by the stenotic coronary artery, N-13 ammonia PET/CT showed higher count densities than Tc-99m MPS on rest study (p < 0.01), and the difference of count density between the stress and the rest studies was also larger on N-13 ammonia PET/CT. Conclusion: Adenosine stress N-13 ammonia PET/CT had higher diagnostic sensitivity and specificity, more reversibility of perfusion defects and greater stress/rest uptake differences than Tc-99m sestamibi MPS. Accordingly, N-13 ammonia PET/CT might offer better assessment of myocardial ischemia and viability.

• Childhood Kidney Diseases
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• v.8 no.1
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• pp.33-42
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• 2004

Purpose : Children with nephrotic syndrome(NS) are under high risk for metabolic bone disease(MBD) as a complication of long-term glucocorticoid therapy. We prospectively evaluated the effect of oral bisphosphonate(alendronate) therapy in children with NS, which has proven efficacy in adult patients with glucocorticoid induced MBD. Methods : Among 58 children with NS, aged 5 to 8 years and haying a disease duration of more than 2 years, 30(51.7%) were enrolled to meet the selection criteria, less than -1.0 Z-scores of lumbar spine bone mineral density(BMD) by dual energy X-ray absorptiometry (DEXA). These 30 children were divided into three groups and each were assigned to receive alendronate, calcitriol, and no-medication, respectively for one year. Lumbar spine BMD was followed up every 6 months and the biochemical indexes were measured before and 1 year after the treatment. There were no significant difference among groups with respect to the average age, the initial BMD, and the cumulative steroid doses. Analysis of the treatment efficacy was done by the % change of BMD and by the changes in Z-scores of lumbar spine BMD. Results : Mean age and disease duration of patients at the initial lumbar spine BMD evaluation was $7.4{\pm}1.7$ years and $2.2{\pm}1.2$ years, respectively. Twenty-three of 30 children(76%) had osteopenia, and seven(23%) had osteoporosis. There was no difference in the biochemical values among the groups, before and 1 year after the treatment(P<0.05). Twenty two children(73.3%) with frequent relapsing or steroid dependant NS had more frequent MBD, compared to the 8 children(26.6%) with infrequent relapsing NS. The one year % changes of BMD were 8.56 in alendronate group, 5.79 in calcitriol group, and 1.9 in no-medication group. The changes in Z-score of lumbar spine BMD increased in the alendronate group and the calcitriol group, but not in the no-medication group. One year % changes of BMD were different among groups(P=0.0002). Significant differences were found between the alendronate and the no-medication group, and between the calcitriol and the no-medication group(P<0.05). There was no difference between the alendronate and the calcitriol group. No serious adverse effect was observed in the alendronate group. Conclusion : Children with NS receiving high dose steroids are under the high risk of BMD and should undergo regular BMD evaluation. Z-score of lumbar spine BMD was a useful parameter in diagnosing low bone mass in children. Alendronate weekly oral therapy was effective and relatively safe in increasing the lumbar spine BMD in children with NS having steroid induced MBD.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.480-498
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• 1997

This study was to investigate the protective and anticirrhotic effects of Mockhyangjokisan and Haewooljoweetang on the liver cirrhosis or fibrosis induced by prolonged bile duct ligation; a new experimental model for cirrhosis and the intraperitoneal injection of dimethylnitrosamine in the rat. The development of fibrosis or cirrhosis and its inhibition by the two prescriptions were examined by the chemical analysis of AST, ALT, and hydroxyproline. The results obtained were as follows. 1. The increase of serum asparate aminotransferase induced by bile duct ligation was inhibited by the administration of Mockhyangjokisan and Haewooljoweetang extract. 2. The increase of serum alanine aminotransferase induced by bile duct ligation was inhibited by the administration of Mockhyangjokisan and Haewooljoweetang extract. 3. The increased level of serum AST and AL T induced by the intraperitoneal injection of dimethylnitrosamine was inhibited by the administration of Mockhyangjokisan and Haewooljoweetang extract. 4. The increasing level of hydroxyproline volume in the damaged liver tissues in the rat was decreased by the oral administration of Mockhyangjokisan and Haewooljoweetang extract. But there were no significant differences in the inhibition rate between the two experimental groups.