• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.45-50
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• 2013

Non-invasive technique CT, called automated computed tomography, is used to detect lesion of a patient when diagnosing human body. Information obtained from CT plays an important role in assembling 3 dimensional images. Recently, new equipment, operated by CT, is required which can be appliable to physical and biological research. In accordance to this quest, micro-CT is invented that produce more detail and concrete information. Images supplied by CT are even more detailed and concrete, so it contributes much to the development of biology and polymer material engineering field. However, there has been little reliable reports regarding measuring information of space dose distribution about exposure dose limit of users operating micro-CT. In addition, little reports regarding space dose distribution of exposure has been known about unwanted diffraction light produced by usage of micro-CT. The exterior of micro-CT is covered by lead, which is for removing exposure of diffraction light. Thus, even if it is good enough to prevent exposure of diffraction light, consistent management of equipment will be required as time goes by and equipment are getting old as well. We measured space dose distribution regarding exposure of diffraction light of users operating micro-CT directly. Therefore, we suggest that proper management should be necessary for users operating micro-CT not to be exposed by unwanted diffraction light.

• Journal of dental hygiene science
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• v.17 no.1
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• pp.73-80
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• 2017

Periodontal diseases occur from the interplay between increased bacterial response and the response of the host immune system over time. Anxiety and depression can impair immunological defense mechanisms, causing accumulation of periodontopathogens and thus exacerbating periodontal disease. We investigated the relationship of anxiety and depression to periodontal diseases in Korean women. In this study, 3,551 women aged ${\geq}19$ years were evaluated based on data from the first year (2010) of the Fifth Korea National Health and Nutrition Examination Survey. The analysis of the factors that caused periodontal diseases revealed that dental floss or interdental toothbrush nonuse behaviors have been shown to increase the risk of periodontal disease (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.14~1.95). After adjusting for conditions such as age, marital status, income, educational level, economic activity, diabetes mellitus, smoking, drinking, and frequencies of toothbrushing and interdental cleaning, we found that anxiety and depression increased the risk of developing periodontal diseases (OR, 1.47; 95% CI, 1.04~2.09). People with anxiety and depression have a higher prevalence of periodontal diseases than people without anxiety and depression. Thus, periodic periodontal care and effective self-care education are needed to manage periodontal diseases.

• Journal of Nutrition and Health
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• v.51 no.2
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• pp.140-152
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• 2018

Purpose: Recently, there has been a worldwide increase in the prevalence of food allergies in children and it may cause nutritional imbalance and poor quality of life for growing children due to dietary restrictions. This study was conducted to quantitatively measure the life burden and related factors of mothers who are the primary caretakers of food-allergic children. Moreover, we generated data for use as a scientific basis for the development of a disease management program to reduce the burden on life from raising food-allergic children. Methods: Mothers of 2,005 children aged 2 years or older and enrolled in Seoul Metropolitan Atopy Free Schools in 2016 who have had diagnosis of food allergy in their lifetime were surveyed. The burden on life of parents with food-allergic children was measured using 17 questions from the Food Allergy Quality of Life-Parental Burden (FAQL-PB) questionnaire, and subjects were asked to respond with a scale of 1 ~ 7. Results: We analyzed the effects of sociodemographic factors of parents and children and the accompanying allergic disease factors on the lives of parents. The number of restricted food items due to food allergy of a child and accompanying diagnosis of atopic dermatitis had a positive (+) effect on the life burden of the parents. Conclusion: Accurate oral food challenge for food allergies should be administered to prevent excessive restriction of food intake. Moreover, efforts should be taken to prevent morbidity accompanying food allergy and relieve symptoms of asthma, allergic rhinitis and atopic dermatitis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.903-910
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• 2016

In this study, the expression level of estrogen receptor in an ovariectomized rat model was effectively enhanced by MS-10, Cirsium japonicum and Thymus vulgaris extract complex, in a reversible manner. MS-10 plays a positive role in enhancing estrogen activity at low concentrations, leading to improved women's health. In order to determine whether or not MS-10 improves menopausal symptoms clinically, a randomized, double-blinded, and placebo-controlled clinical study was carried out on 62 middle-aged women treated with 500 mg of MS-10 or placebo daily for 12 weeks. Clinical menopausal symptoms were evaluated by Kupperman's index (KI) detecting various menopausal symptoms, including hot flushes, parenthesis, insomnia, nervousness, melancholia, dizziness, fatigue, rheumatic pain, palpitations, formication, and headaches. Total KI score decreased significantly by about 18% upon ingestion of MS-10. Colpoxerosis, a main symptom of menopause, was significantly reduced by about 21% upon ingestion of MS-10 in contrast to placebo. In addition, reduction of insulin-like growth factor-1 with age was improved by over 10% upon ingestion of MS-10, whereas there were no significant difference with placebo. No side effects appeared after treatment with MS-10. Thus, MS-10 can be suggested as a plausible natural substance for improving women's health.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.512-519
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• 2018

Phthalates widely used in the manufacture of plastics have deeply penetrated into our everyday lives. Recently, a concern over the toxicity of phthalates on thyroid, has been raised but in most of cases, the doses employed were unrealistically high. To investigate the effects of phthalates on thyroid, we investigated the effects of the repeated oral exposure to low to high doses (0.3, 3, 30 and 150 mg/kg) di-2-ethylhexylphthalate (DEHP) from weaning to maturity for 90 days in juvenile rats on the thyroid. The histological examination revealed that DEHP significantly induced hyperplasia in the thyroid from the doses of 30 mg/kg, which was confirmed with Ki67 staining. In line with this finding, increased mRNA expression of thyrotropin releasing hormone (Trh) was observed in the thyroid of female at 0.3 mg/kg and 150 mg/kg as determined by RNAseq analysis. Moreover, significantly increased expression of parathyroid hormone (Pth) in the female at 0.3 mg/kg, and thyroglobulin (Tg) and thyroid hormone responsive (Thrsp) in the male at 0.3 mg/kg were noted in the blood, of which changes were substantially attenuated at 150 m/kg, alluding the meaningful effects of low dose DEHP on the thyroid hormone regulation. Urinary excretion of mono-2-ethylhexyl-phthalate (MEHP), a major metabolite of DEHP was determined to be 4.10 and 12.26 ppb in male, 6.65 and 324 ppb in female at 0.3 and 30 mg/kg DEHP, respectively, which fell within reported human urine levels. Collectively, these results suggest a potential adverse effects of low dose phthalates on the thyroid.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.101-109
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• 2015

Objectives: The purpose of the study is to investigate the knowledge and attitude towards radiation protection after radiation safety management education in dental hygiene students. Methods: After receiving informed consents, a self-reported questionnaire was carried out for 135 dental hygiene students in Busan on June 17 for preliminary survey and September 3 for post-education survey, 2011. The questionnaire was modified from Han and consisted of 5 questions of general characteristics, 6 questions of radiation use, 7 questions of scholastic characteristics, 15 questions of knowledge towards radiation safety management, and 15 questions of attitude towards radiation safety management. Cronbach's alpha was 0.808 in the knowledge towards radiation safety management. Attitude towards radiation safety management included 15 questions of general attitude towards radiation safety management, individual and patient, and attitude toward radiation exposure reduction measured by Likert 5 scale. Cronbach's alpha was 0.970 in the attitude towards radiation safety management. Data were analyzed using SAS version 9.2 for educational analysis, technical analysis and multivariate analysis, paired t-test, and GLM. Results: Significant differences were shown in the knowledge and attitudes towards radiation safety management; the level of knowledge was respectively $9.8{\pm}3.0$ and $12.9{\pm}1.9$ points before and after education, and the level of attitude was $4.28{\pm}0.51$ and $4.53{\pm}0.47$ before and after the education. The levels of knowledge and attitude according to general characteristics showed a significant differences in grade and academic results. Post-education survey suggested that the education is very important and necessary and can change the knowledge and attitude towards radiation safety management in the dental hygiene students. Conclusions: Through the radiation safety management education, the levels of knowledge and attitude towards radiation safety management have changed significantly, which showed that the radiation safety management education proved to be very effective. Therefore, an effective radiation safety management education program is necessary to improve the levels of knowledge and attitude towards radiation safety management in the dental hygiene students.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.709-716
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• 2008

Purpose: Autogenous transplantation of teeth can be defined as transplantation of teeth from one site to another in the same individual, involving transfer of impacted or erupted teeth into extraction sites or surgically prepared sockets". Successful autogenous transplantation of teeth depends upon a complex variety of factors. Such factors include damage to the periodontal ligament of the donor tooth, residual bone height of the recipient site, extra-oral time of tooth during surgery. Schwartz and Andreasen previously reported that autogenous transplantation of teeth with incomplete root formation demonstrated higher success rate than that of teeth with complete root formation. Gault and Mejare yielded similar rate of successful autogenous transplantation both in teeth with complete root formation and in teeth with incomplete root formation when appropriate cases were selected. This case report was aimed at the clinical and radiographic view in autogenous transplantation of teeth with complete root formation. Materials and Methods: Patients who presented to the department of periodontics, Chonnam National University Hospital underwent autogenous transplantation of teeth. One patient had vertical root fracture in a upper right second molar and upper left third molar was transplanted. And another patient who needed orthodontic treatment had residual root due to caries on upper right first premolar. Upper right premolar was extracted and lower right second premolar was transplanted. Six months later, orthodontic force was applied. Results: 7 months or 11/2 year later, each patient had clinically shallow pocket depth and normal tooth mobility. Root resorption and bone loss were not observed in radiograph and function was maintained successfully. Conclusion: Autogenous transplantation is considered as a predictive procedure when it is performed for the appropriate indication and when maintenance is achieved through regular radiographic taking and follow-up.

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.903-913
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• 2014

Objectives: The purpose of the study was to investigate the content analysis of daily tooth cleaning service records by caregivers in a long-term care facility. Methods: The data were analyzed by qualitative research based on content analysis of the daily records of the processes and results of daily tooth cleaning service. Twenty caregivers provided tooth, gum and denture cleaning service after breakfast, lunch, and dinner to 48 elderly residents. The study lasted about two weeks(from August 4 to August 20, 2014). The researcher reconstructed the language by repeatedly reviewing the caregivers statements in the records. The content categories were derived from the records through a reiterative manual comparative analysis. Using constant comparison method, reconstructed meanings were incorporated into various meanings and reanalyzed by final categories called as analytic coding. In order to validate the reliability, 6 times of discussion made the common meanings through a master's degree student and a dental hygiene professor. Results: The caregivers identified lack of understanding and ability to recognize the functional physical and mental changes in the elderly. The elderly had difficulty in recognizing silent communication and daily tooth cleaning. The caregivers were so strenuous in taking care of the daily tooth cleaning service for the elderly. At last, they gave up the daily tooth cleaning service and took on it to the guardians. They found that there was no social supporting network for oral health of the elderly residents. Conclusions: Caregivers had insufficient understanding of the functional physical and mental changes in the elderly residents, and they had difficulty providing daily tooth cleaning service to the elderly due to poor skill and abilities.

• Journal of Periodontal and Implant Science
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• v.50 no.1
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• pp.56-66
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• 2020

Purpose: A stability-measuring device that utilizes damping capacity analysis (DCA) has recently been introduced in the field of dental implantology. This study aimed to evaluate the sensitivity and reliability of this device by measuring the implant stability of ex vivo samples in comparison with a resonance frequency analysis (RFA) device. Methods: Six implant beds were prepared in porcine ribs using 3 different drilling protocols to simulate various implant stability conditions. Thirty-six pork ribs and 216 bone-level implants measuring 10 mm in height were used. The implant beds were prepared using 1 of the following 3 drilling protocols: 10-mm drilling depth with a 3.5-mm-diameter twist drill, 5-mm drilling depth with a 4.0-mm-diameter twist drill, and 10-mm drilling depth with a 4.0-mm-diameter twist drill. The first 108 implants were external-connection implants 4.0 mm in diameter, while the other 108 implants were internal-connection implants 4.3 mm in diameter. The peak insertion torque (PIT) during implant placement, the stability values obtained with DCA and RFA devices after implant placement, and the peak removal torque (PRT) during implant removal were measured. Results: The intraclass correlation coefficients (ICCs) of the implant stability quotient (ISQ) results obtained using the RFA device at the medial, distal, ventral, and dorsal points were 0.997, 0.994, 0.994, and 0.998, respectively. The ICCs of the implant stability test (IST) results obtained using the DCA device at the corresponding locations were 0.972, 0.975, 0.974, and 0.976, respectively. Logarithmic relationships between PIT and IST, PIT and ISQ, PRT and IST, and PRT and ISQ were observed. The mean absolute difference between the ISQ and IST values on a Bland-Altman plot was -6.76 (-25.05 to 11.53, P<0.05). Conclusions: Within the limits of ex vivo studies, measurements made using the RFA and DCA devices were found to be correlated under a variety of stability conditions.

• Journal of dental hygiene science
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• v.6 no.3
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• pp.159-162
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• 2006

This study examined the relationship between the quantity of Streptococcus mutans and Lactobacillus spp. related to dental caries and the degree of acidity in saliva. A total of 240 saliva samples were taken from 80 subjects at the faculty of dentistry in Skopje, Macedonia. The saliva samples were taken by stimulating saliva production stimulation with paraffin chewing. However, no stimulation was applied when obtaining the samples used for measuring the pH. The data showed that in the caries group, S. mutans in 1 ml of saliva formed colonies with confluent growth (CFU > $10^6$ and $10^4-10^5$) in 100% of samples, whereas the Lactobacillus spp. formed colonies with confluent growth in 78.3%. In contrast, no colonies with confluent growth (CFU > $10^6$ and $10^5$) were found in the control group (with healthy intact teeth). In the caries group, the pH of the saliva was slightly acidic (pH = 5.90 - 6.50) and the buffering capacity was very low (below 0.7 ml of saliva per min). On the other hand, the pH of the saliva in the control group was neutral (pH 7.01 - 7.7) and the buffering capacity was high (over 1 ml of saliva per min). The increased number of S. mutans and Lactobacillus spp. in 1 ml of saliva (above $10^5$ CFU or more) from the CRT (Caries Risk Test, Vivadent, Liechtenstein) bacteria test can indicate an increased caries risk as well as slightly higher acidity of the saliva. Overall, these results reveal that the caries risk can be predicted by simply measuring the pH and buffering capacity of saliva, and can be used to monitor the effect of dental hygiene practices with the aim of preventing dental caries.