• Journal of dental hygiene science
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• v.2 no.2
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• pp.105-113
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• 2002

This study was aimed to investigate the practice on the infection control and dental waste disposal in dental clinic. The data used in this study had been collected in 100 dental clinics located in Seoul city from August to October, 2001. It was shown that examination instruments, oral surgery instruments, and periodontal instruments were almost sterilization in dental clinic. It was high in the recognition of individual protection but it was low in the degree of practice. Therefore, the practice in infection control is very important to dental team for safety of patients and operators.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.432-439
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• 2004

Korean certification regulation for particulate filtering respirators requires inward leakage (IL) test as European Standards (EN) and the standard levels of regulation are the same as those of EN. This study was conducted to evaluate particulate filtering respirators being commercially used in the market by using IL and assess the characteristics of IL. The study began with discussing the concept of IL, comparison of IL with fit test, and IL measurement method. Three brands of half masks and 10 brands of filtering facepieces (two top class, four 1st class and four 2nd class), total 13 brands respirators, and 10 test panels (subjects) who were classified in 9 facial grids in accordance with face length and lip length, were selected for IL test. IL tests were conducted in the laboratory of 3M Innovation Center which was established by EN standard. As expected ILs of half masks were lower than those of filtering facepiece mask. ILs of half masks and some filtering facepieces were significantly different in manufacturers. ILs of 1st class filtering facepieces were found to be much more than those of 2nd class and thus the result would cause wearers to get confused to select a mask. Four of six brands being no compliance with standards were thought that they should be tested again for certification because of a lot of differences from standards. There were no significant differences among ILs of five exercises. In 6 out of 13 brands lognormal distribution of ILs may be a better fit distribution and in 7 brands both lognormal and normal distributions were rejected. The result indicates that geometric mean may be better than arithmetic mean to establish standard.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.514-520
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• 2008

Purpose: Many attempts have been made to describe ideal facial proportions for over two thousands year and constantly lasted till now. Dr. Marquardt has derived supposedly ideal facial proportions from the facial golden mask using golden ratio of 1 : 1.618. On the other hand, facial reducing surgeries such as mandible angle reduction are popularized in Asia because the width of mid and lower face of Korean is recognized to be wider. The purpose is to analyze characters of Korean university students' faces in horizontal plane and establish the objective data for facial width distributions and clinical applications. Methods: We applied the facial golden mask to the photographs in 1000 cases, compared the width of mid and lower face between the facial golden mask and Korean university students' faces. And we first calculated the horizontal ratio(HR) of middle and lower face each for using comparative scale of width, facial golden mask. We divided 1,000 cases into 3 groups by degrees of HR and analyzed data of HR on each groups. Using calculated horizontal ratio, we newly invented the cumulative frequency of distribution graphs in Korean university students' faces. Results: Mean data of HR were over 1.0 in all groups, which means that Korean university students' faces are typically wider than facial golden mask in horizontal planes. And this study was statistically significant(p- value < 0.05). Clinically using the cumulative frequency distributions of Korean university students' face width, we can easily explain changes of facial width to patient after facial reducing surgery and describe the changes into objective data. Conclusion: This study concludes thatKorean university students' faces are wider than facial golden mask is significantly true and the cumulative frequency of distribution graphs are expected to be widely used for comparison of results in facial reducing surgery.

• KSBB Journal
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• v.28 no.6
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• pp.387-393
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• 2013

In this study, the domestic onion skin has been used to investigate the anti-wrinkle effect of the ethanolic extract. The onion skin has been known to contain a large amount of antioxidant including quercetin. Solvent extraction by 80% ethanol was carried out of the onion skin. The high amount of quercetin have been identified using HPLC as a bioactive compound. The extraction yield of the quercetin increased according to temperature up to $80^{\circ}C$. Two different antioxidant assays (DPPH and ABTS) were performed to determine the free-radical scavenging activity of onion skin extracts. The antioxidant activities ($EC_{50}$ of DPPH) of the vitamin C and the onion extracts were 2.2 and $5.09{\mu}g/mL$, respectively. The results of ABTS tests were 2.33 (of vitamin C) and $2.40{\mu}g/mL$ (of the onion extracts), respectively. In a clinical study, a panel of 10 female volunteers between the ages of 30 and 40 (mean age: 42 years) was given a mask pack containing 1% of this extracts for 4 weeks. It was shown that a highly significant reduction in the deep and moderate wrinkled was obtained with those treated with this onion extracts as compared to the control group. The reduction in deep wrinkles increased with time. Eye wrinkle were reduced statistically significant (p<0.05). The application of the proper topical cream and mask pack containing onion skin extracts has therefore shown to be effective enhancing anti-wrinkle activities.

• Journal of Korean society of Dental Hygiene
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• v.11 no.5
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• pp.637-647
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• 2011

Objectives : This study was performed to enhance infection control and to establish the fundamental and practical improvement by the survey on personal protection of dental personnels with health science college students. Methods : We performed the survey with 585 individual students affiliated with health science in Jeonbuk province and statistically analyzed by SPSS 12.0 program. Results : The frequencies of the clinic gown as a personal protection were 96.0% of dentists (p<0.01) and 88.0% of dental hygienists (p<0.05) respectively in college-associated dental hospital when we compared with institution scale. The frequencies of the medical gloves as a compulsory personal protection were 47.2% of dentists and 34.6% of dental hygienists respectively (p<0.001). The frequencies of the medical mask as a compulsory personal protection were 84.0% of dentists (p<0.001) and 52.2% of dental hygienists (p<0.05) respectively shown by freshman students. The frequencies of the safety glasses as a compulsory personal protection were 12.3% of dentists and 2.5% of dental hygienists shown by freshman students (p<0.001). Conclusions : The results reflect that current dental personnel's concern of personal protection need to be increased continuously in accordance with current demands and eventually suggest their effort to put their action on personal protection in their dental office.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.292-301
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• 2021

Objectives: Wearing medical masks has been recommended since the declaration of coronavirus disease-19 (COVID-19) as a pandemic disease. Certified medical masks are evaluated according to filtration efficiency and facial inhalation resistance. However, some people use non-certified common masks. This study aimed to evaluate various non-certified commercial masks based on the certification criteria for medical masks. Methods: Twenty mask products (three anti-droplet, three disposable dental, eight fashion, three cotton, and three children's masks) were selected. For performance evaluation, filtration efficiency and facial inhalation resistance tests were conducted. The evaluation method followed the certification method for KF-certified masks of the Ministry of Food and Drug Safety (MFDS) and the N95 respirator of the National Institute for Occupational Safety and Health (NIOSH). Results: None of the 20 masks met the KF94 certification standard set by the MFDS. Four and three masks respectively met the KF80 certification standard and the N95 standard of NIOSH. Filtration efficiency was significantly higher in three-layer masks than in single layer masks. Pleated-type masks had higher filtration efficiency than cone-type masks. There was no correlation between the structure of masks and facial inhalation resistance. Conclusion: While no masks complied with the KF94 certification standard, a few masks met the KF80 and the N95 certification standards of NIOSH. Although some people wear non-certified commercial masks, protection from aerosols is not guaranteed by such masks. Evaluation of the protection efficiency of non-certified mask against microbiological infection is needed for the prevention of infectious disease.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.350-362
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• 1999

Background: Acute Respiratory failure which is developed after extubation in the weaning process from mechanical ventilation is an important cause of weaning failure. Once it was developed, endotracheal reintubation has been done for respiratory support. Noninvasive Positive Pressure Ventilation (NIPPV) has been used in the management of acute or chronic respiratory failure, as an alternative to endotracheal intubation, using via nasal or facial mask. In this study, we evaluated the usefulness of NIPPV as an alternative method of reintubation in patients who developed acute respiratory failure after extubation. Method: We retrospectively analyzed thirty one patients(eighteen males and thirteen females, mean ages $63\pm13.2$ years) who were developed acute respiratory failure within forty eight hours after extubation, or were extubated unintentionally at medical intensive care unit(MICU) of Asan Medical Center. NIPPV was applied to the patients. Ventilatory mode of NIPPV, level of ventilatory support and inspiratory oxygen concentration were adjusted according to the patient condition and results of blood gas analysis by the attending doctors at MICU. NIPPV was completely weaned when the patients maintained stable clinical condition under 8 $cmH_2O$ of pressure support level. Weaning success was defined as maintenance of stable spontaneous breathing more than forty eight hours after discontinuation of NIPPV. Respiratory rate, heart rate, arterial blood gas analysis, level of pressure support, and level of PEEP were monitored just before extubation, at thirty minutes, six hours, twenty four hours after initiation of NIPPV. They were also measured at just before weaning from NIPPV in success group, and just before reintubation in failure group. Results: NIPPV was successfully applied to thirty-one patients of thirty-two trials and one patient could not tolerated NIPPV longer than thirty minutes. Endotracheal reintubation was successfully obviated in fourteen patients (45%) among them. There was no difference in age, sex, APACHE III score on admission at MICU, duration of intubation, interval from extubation to initiation of NIPPV, baseline heart rate, respiratory rate, arterial blood gas, and $PaO_2/FiO_2$ between the success and the failure group. Heart rate and respiration rate were significantly decreased with increase $SaO_2$ after thirty minutes of NIPPV in both groups(p<0.05). However, in the patients of failure group, heart rate and respiratory rate were increased again with decrease in $SaO_2$ leading to endotracheal reintubation. The success rate of NIPPV treatment was significantly higher in the patients with COPD compared to other diseases(62% vs 39%) (p=0.007). The causes of failure were deterioration of arterial blood gas without aggravation of underlying disease(n=9), aggravation of undelying disease(n=5), mask intolerance(n=2), and retained airway secretion(n=l). Conclusion: NIPPV would be a useful therapeutic alternative which can avoid reintubation in patient who developed acute respiratory failure after extubation.

• Journal of dental hygiene science
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• v.7 no.1
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• pp.1-7
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• 2007

This study aimed to provide basic information on dental hygienists' practicing the prevention of infections by figuring out their actual conditions in dental clinics. The subjects of the study were the dental hygienists who participated in the continuing medical education of Incheon & Gyeonggi-do association and Seoul city association in October and November 2005 and the self-administered surveys were used for the prevention of infections. The results were as below. 1. In terms of education experiences of infection prevention, those who answered "there were" were 72 persons (42.9%) and those who followed the educational route for infection prevention were "through the in-house education from the hospital" and they were 42 persons (58%), which were highest. 2. In terms of the injury experiences, those who answered "there were" were 147 persons (87.5%) and the number of annual injury out of 147 persons with injury experiences was 7.7 time. For the tools that were damaged, 125 persons (75%) damaged the "explorer," which was highest. 3. For the experiences of being infected with contagious diseases, those who answered "there were" were 6 persons (3.6%) and there were four persons for "hepatitis B", one person for "rubella" and one person for "TB." 4. The questions with high practice scores were as in the following: "2. I wash my hands after conducting medical examinations (1.86 points)," "7. I always close the lid of a shot of Novocain after doing local anesthesia (1.86 points)" and "20. I separate and collect the wastes and give them to those who treat accumulated materials (1.85 points)". Meanwhile, the questions with low practice scores were as below: "16. I change my medical gowns (doctor wears) once a day (0.24 point)" and "I wash my medical gowns every time after examining patients with contagious diseases (0.52 points)." 5. The question with high knowledge was as below: "1. The contagion during the dental treatment is determined by source of infection, infection methods, infection routes and the host that is prone to infection (0.95 point)" and the question with the lowest knowledge was "5. HBV(hepatitis B) is destroyed after adding 95oC of heat for more than 5 minutes (0.27 points)." 6. The question with the highest organization-related factors was "I am always ready to use a mask, gloves, etc. if necessary" (0.89 points)" and the question with the lowest score was "There is a guideline that I can refer when I am exposed to dangerous situations related to the contagion in my workplace (0.33 point)." 7. In terms of the equipment conditions of protectors in medical environments, 168 persons for (disposable) mask (100%), 167 persons for disposable gloves (Latex) (99.4%), which meant that most of them were equipped with them. On the contrary, 108 persons (64.3%) are equipped with the protectors for frontal faces, which is the lowest and 165 persons (98.2%) said that they had autoclave in their disinfecting and sterilizing devices.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.35-41
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• 2016

Particulate filtering facepiece respirators (PFFR) is one of the most widely used items of personal protective equipments, and a tight fit of the respirators on the wearers is critical for the protection effectiveness. In order to effectively protect the workers through the respirators, it is important to find and evaluate the ways that can be readily applicable at the workplace to improve the fit of the respirators. This study was designed to evaluate effects of mask style (cup or foldable type) and donning training on fit factors (FF) of the respirators, since these are available at various workplace, especially at small business workplace. A total of 40 study subjects, comprised of 30~50s aged male and female workers in metalworking industries, were enrolled in this study. The FF were quantitatively measured before and after training related to the proper donning and use of cup or foldable-type respirators. The pass/fail criterion of FF was set at 100. After the donning training for the cup-type mask, subjects who passed the fit test were increased from 10 to 33. Moreover, the geometric mean (GM) of FF was increased by 340% in subjects who failed the test. In addition, the training effects for the cup-type mask were significant in female and 50s aged subjects. On the other hand, although the GM of FF for the foldable-type mask was also increased after the donning training, the GM of FF for the foldable-type mask and it's increase rate were smaller as compared to the cup-type mask. Furthermore, the differences of the increase rates of the GM of FF in sex and aged of the subjects were not significantly for the foldable-type mask. The multi-distribution of leak points for the foldable-type mask may be one of causes for the less effect of training on the fit of the foldable-type mask. These results imply that the raining on the donning and use of PFFR can enhance the protection effectiveness of cup or foldable-type mask, and that the training effects for the foldable-type mask is less significant than that for the cup-type mask. Therefore, It is recommended that the donning training and fit tests should be conducted before the use of the PFFR, and that efficient tranining programs for the foldable-type mask are required.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.52-60
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• 2018

This study compares the differences of the fit factor by the order of wearing preference between Particulate filtering facepiece respirators(PFFR) and glasses when participants wore simultaneously and a survey of physical and visual complaint. Recognition level about fit of respirators was investigated and the educational (before- and after-) effect of the fit factor. When participants wore PFFR and glasses, physical complaints were nose pressure, slipping, nose and ear pressure, ear pressure and rim loosen, the most highly physical complaints were nose pressure. Visual complaints were demister, blurry vision, dizziness, visual field, and lens dirty, the most highly visual complaints were demister. But, there was significant difference in physical complaint such as nose pressure(10.3%), slipping (23.0%), nose and ear pressure(14.3%), and rim loosen(16.2%), visual complaint such as visual field(13.8%) and lens dirty(32.4%). For the recognition of fit of respirators, respirators fitness, leak site, an initial point and an object, faulty factor, recognition level was higher. Fit factor was increased after education of proper wearing of respirator. Change of the fit factor was smaller compared to the normal breathing and after 6 actions in case of after education. Questionnaire consisted of general characteristics and physical/visual complaint, recognition of fit. Complaints were measured after the QNFT with multiple choices. Quantitative fit factor was measured by device and compared the result of (before- and after-) educational effect. Also, we selected to 6 actions (Normal breathing, Deep breathing, Bending over, Turning head side to side, Moving head up and down, Normal breathing) among 8 actions OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The fit factor was higher after the training (p=0.000). Descriptive statistics, paired t-test, and Wilcoxon analysis were performed to describe the result of questionnaire and fit test. (P=0.05) Therefore, it is necessary to investigate the quantitative research such as training program and glasses fitting factor about the wearing of PFFR and glasses simultaneously.