• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.434-442
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• 2017

The purpose of this study was to examine the influence of type of malocclusion and orthodontic treatment awareness on quality of life among orthodontic patients in the region of Busan as well as to develop an educational program tailored to the type of malocclusion as a way to improve quality of life. A survey was conducted for approximately 6 months from December, 2015, and the answer sheets from 472 respondents were analyzed. The most common painful area was the teeth, and this case was most predominant in the respondents with level 2 malocclusion, who differed from others in that regard (p<0.001). Regarding the relationship between satisfaction with orthodontic treatment and quality of life, respondents who were more satisfied currently and who were neither quite confident nor quite unconfident were ahead of their counterparts in quality of life. Concerning the reason for receiving orthodontic treatment, quality of life was lower among patients who started to receive treatment due to pronunciation problems (p=0.013), chewing difficulty (p<0.001), and temporomandibular joint click sound (p<0.001). With regard to influential factors on oral health-related quality of life, time for starting to receive orthodontic treatment was most influential (p<0.001), followed by current satisfaction (p<0.001), changes in confidence (p=0.003), self-rated teeth status (p=0.008), and type of occlusion (p=0.019). Therefore, accurate analysis of the oral health status of orthodontic patients and customized oral health education are required to improve quality of life even during the period of orthodontic treatment.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.146-159
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• 2020

The objective of our study was to analyze the distribution and composition of fish species and their community characteristics in agricultural waterways in the six water systems-Mankyung River, Seomjin River, Namhae Region, Tamjin River, Yeongsan River, and Dongjin River-during 2017-2018. Little is known about the distributions and community characteristics of the aquatic biota of agricultural waterways in Korea, even if the water bodies have important roles as spawning areas or habitats for fish. In this study, we identified 3,633 fish individuals in the waterways, belonging to 53 species, eleven families, and six orders (dominant species: Tanakia koreensis, T. lanceolate) and 7,108 fish individuals in the main rivers, belonging to 57 species, fifteen families, and nine orders. Moreover, three endangered wildlife (designated by the Ministry of Environment, Korea)-T. somjinensis, Acheilognathus majusculus and Coreoperca kawamebari-were found in the waterways. By fish guild analysis, we found that many waterways had a lower proportion of sensitive species and a higher proportion of omnivore species than those of the main rivers, which indicates a feature of a disturbed environment. In addition, by grouping with environmental variables, we found the group of waterways with high substrate complexity had a higher diversity index (Shannon index) and a lower dominance index (Simpson index) than that of simple substrate complexity. Overall, our study represents the characteristics of fish habitats in agricultural waterways and suggests the need to manage them and study further.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.335-352
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• 2014

In this study, we investigated and analysed the water quality, distribution of the vegetation and the wildlife to seven wetlands in Donghae city. As a result, most of the wetlands was found to be very poor water quality and some specific pollutants from entering the wetland. A total of 234 taxa on vegetation were identified including 207 species, 24 varieties, 3 formaes, 168 genera and 69 families. 2 species were recorded as designated rare plant of Korea Forest Service. The naturalized plants were 27 species. The urbanization rate of naturalization index was 8.4% and 11.6% respectively. The number of benthic macroinvertebrate taxa was 35 species, 26 families, 12 orders, 5 classes and 3 phylums. Rare species were recorded 3 species. Taxa for fishes were 5 family and 5 species. Endangered wildlife was found 1 species. Most wetlands in Donghae city were the relatively small in size, and some wetlands were separately located from forest and river ecosystems. It was limited inflow and outflow of species into a wetland from the outside. However, various vegetation were found at whole wetlands and some special species also inhabited. The wetlands performed the role as a habitat of wild life.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.357-367
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• 1993

The purpose of this study was to evaluate the fracture strength of class II restored premolars with amalgam, posterior composite, amalgam - Ketac silver, resin - Ketac silver restorations at marginal ridge. Fifty extacted maxillary and mandibular premolar teeth that were caries free, fracture free, and restoration free were selected and randomly divided into five groups : Group 1 : 10 intact teeth, Group 2 : 10 teeth with class II cavities and restored with, amalgam, Group 3: 10 teeth with class II cavities and restored with posterior resin, Group 4 : 10 teeth with class II cavities and restored with amalgam - ketac silver, Group 5 : 10 teeth with class II cavities and restored with resin - Ketac silver. All teeth were mounted in base of dental stone within metal rings of 2cm diameter, exposing only the crown portion. Class II mesio - occlusal or disto - occlusal cavities were prepared into specimens of Group 2 through 5 by using a No. 710 fissure bur. The occlusal portion was prepared to a faciolingual width of 1.5mm and a pulpal depth of 1.5mm. The proximal protion was prepared to a faciolingual width of 4mm, a occlusogingival height of 4mm, and a gingival floor of 1.5mm. The teeth in Group 2 and 3 were resotored with silver amalgam apd posterior resin respectively. In Group 4 and 5, proximal portions were first filled with Ketac silver 1.5mm gingivally and remaining cavities were restored with amalgam and posterior resin respectively. All specimens were stored in 100 % relative humidity at $37^{\circ}C$ for 48 hours before testing. All teeth were subjected to a compressive load in a Universal Instron Testing Machine at marginal ridges. The loads required to fracture the restorations were recorded in killograms and the data obtained were subjected to statisticall analysis. The results were all follows : 1. The fracture strength of Group 1 which were unprepared were $100{\pm}10.1\;kg$ and the higher values than Group 2, 3, 4, 5 which were prepared and resotred. 2. In restored groups, Group 2 had the higher fracture strength($81.8{\pm}12.4\;kg$) than other groups and Group 4 had the lowest fracture strength($66.8{\pm}9.2kg$). 3. There were significant differences between fracture strength of between Group 1 and Group 3, 4, 5(P<0.05), but not significant difference between fracture strength of Group 2, 3, 4, 5(P>0.05).

• The korean journal of orthodontics
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• v.40 no.5
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• pp.334-341
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• 2010

Objective: The purpose of this study was to evaluate morphologic differences in the mandibular arch between Egyptian and Korean subjects. Methods: The Egyptian sample consisted of 94 mandibular casts (35 Class I, 32 Class II and 27 Class III). The Korean sample consisted of 462 mandibular casts (114 Class I, 119 Class II, and 135 Class III). The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket points were calculated for each tooth. The subjects were grouped according to arch form to compare the frequency distribution of the 3 arch forms between the ethnic groups in each Angle classification. Results: Egyptians had significantly narrower intermolar and intercanine widths ($p$ < 0.001), and shallower intermolar and intercanine depths ($p$ < 0.001) than Koreans. There was an even frequency distribution of the 3 arch forms within the Egyptian group ($p$ = 0.46). However, in the Korean group, the most frequent arch form was the square arch form (46.7%), while the frequency of the tapered arch form was significantly lower (18.8%). Conclusions: These results might provide helpful information in evaluating morphologic differences between ethnic groups in selection of preformed superelastic archwires.

• The korean journal of orthodontics
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• v.39 no.1
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• pp.36-42
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• 2009

Objective: The purposes of this study were to provide an epidemiologic data base related to the orthodontic treatment need and to know the changing trends about treatment modality of private orthodontic clinics. Methods: Distribution, trends and orthodontic treatment plan of malocclusion patients were investigated in 1,620 consecutive patients who had been visited and examined in 4 private orthodontic clinics located in Seoul from 2003-2006. Results: Percentage of male and female patients was 26.9% and 73.1% respectively Age distribution had shown that percentage of the patients above 13 years was 78.9%, and above 19 years was 59.0%. Average age of whole patients was 20.5 years. With regard to Angle classification, each percentage of Class I, Class II division 1, Class II division 2 and Class III malocclusion was 38.9%, 34.8%, 2.3% and 24.0%. The percentage of extraction cases(00.9%) outnumbered nonextraction cases(39.1%) and 46% of extraction cases were upper and lower 1st premolar extraction cases. Patients who had chose treatment with fixed appliance and orthognathic surgery was 10.2%. Conclusions: Because the high percentage of adult, Class II malocclusion and orthognathic surgery cases in patients of private orthodontic clinics were shown in this study, orthodontic education program and national health policy in Korea need reformation.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.130-141
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• 2020

National parks in Korea are subject to a survey of natural resources every five years, according to the Natural Parks Act. This study analyzed the insect diversity in each of the 21 national parks conducted as part of the Third Nature Resource Survey of National Parks (2010~2018). It compared insect diversity in each national park national biodiversity with insect diversity in all national parks and analyzed the uncollected sub-taxonomic groups of each taxonomic group and the legally protected species. The Third Nature Resource Survey identified 5,584 species in 456 families in 21 orders in all national parks, and they accounted for 31.3% of 17,848 species in the national insect diversity. By taxonomic group, Lepidoptera was the most frequently found with 2,195 species, followed by beetles (1,495 species), fellings (712 species), and stink bugs (515 species). By national park, Odaesan national park showed the highest insect diversity with 1,963 species, followed by Sobeaksan national park (1,511), Hanryeohaesang national park (1,321), Gayasan national park (1,282), Juwangsan national park (1,265), Dadohaehaesang national park (1,264), Woraksan national park (1,251), and Jirisan national park (1,240). The legally protected species included 3 species of endangered species rank I, 11 species of endangered species rank II, 12 climate change indicator species, 139 endemic species, and 532 species requiring approval for cross-border transfer.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.337-346
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• 2014

This study was carried out to investigate the terrestrial diurnal insects in the Donggang river neighborhood. A total of 455 species belonging to 117 families of 16 orders were identified from 3,001 collected terrestrial insects around the Donggang river. Species richness showed as follows; Coleoptera (166 species, 34.48%), Hemiptera (11 species, 24.0%), Lepidoptera (68 species, 14.95%), Diptera (40 species, 8.79%), Hymenoptera (28 species, 6.15%), Orthoptera (18 species, 3.96%), Odonata (7 species, 1.54%), and others (3.74%). The Coleoptera consisted of the most number of individuals (33.2%), followed by 951 Hemiptera (31.7%), 662 Lepidoptera (20.7%), 155 Orthoptera (5.2%), 100 Diptera (3.3%), 87 Hymenoptera (2.9%), 30 Odonata (1.0%) and others (2.0%). Among them, 1 endangered species of Ministry of Environment, 1 Critically Endangered Korean species, 7 Vulnerable Korean species (VU), and also 2 Near Threatened Korean species were surveyed in the Donggang river neighborhood.

• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.398-414
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• 2011

The flora in the region of Mt. Sobaeksan National Park ($N36^{\circ}50^{\prime}-37^{\circ}50^{\prime}$, $E128^{\circ}20^{\prime}-128^{\circ}43^{\prime}$) was surveyed from April of 2005 to October of 2011. The vascular plants from 27 field surveys were revealed to total 869 taxa, comprising 112 families, 429 genera, 756 species, four subspecies, 91 varieties and 18 forms. Sixty-eight taxa were the first records from this region. This field study discovered significant plants in various categories. Korean endemic plants numbered 25 taxa, and 18 taxa designated by the Korean Forest Service as rare plants were investigated in this region. The taxa in category II of rare and endangered plants and higher than the third degree among the floristic regional indicator plants designated by the Korean Ministry of the Environment were three taxa and 75 taxa, respectively. From a geographical perspective, limited distribution of Saxifraga octopetala, Corydalis grandicalyx, Aegopodium alpestre, and Polygonatum acuminatifolium at a latitude higher than that of Sobaeksan National Park suggest that Sobaeksan National Park might be the limit line of the distribution of the taxa. Stewartia koreana demonstrate a reversed pattern from the taxa above, occurring at a latitude lower than that of Sobaeksan National Park. In addition, naturalized plants of 53 taxa were recorded.

• Korean Journal of Plant Taxonomy
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• v.50 no.1
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• pp.27-55
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• 2020

We investigated the flora of Ibamsan Mt. and Baekamsan Mt., and discuss here important vascular plants found on these mountains. We created a plant list using voucher specimens collected from Ibamsan Mt. and Baekamsan deposited at CNU. There are 769 taxa in Ibamsan Mt. and Baekamsan Mt., consisting of 116 families, 403 genera, 687 species, 16 subspecies, 58 varieties, and 8 forms. Twenty-four endemic plants of Korea were found, including Coreanomecon hylomeconoides Nakai and Eranthis byunsanensis B. Y. Sun. There are 15 rare plants on Ibamsan Mt. and Baekamsan as designated by the Korea Forest Service, including Iris koreana Nakai and Chamaegastrodia shikokiana Makino & F. Maek., as well as 14 red-list plants as designated by the Ministry of the Environment, including Lycoris chinensis var. sinuolata K. Tae & S. C. Ko ex K. Tae & S. C. Ko and Cymbidium macrorhizon Lindl. In total, there are 133 taxa of floristic regional indicator plants, including four level V taxa, such as Iris koreana Nakai; ten level IV taxa, such as Lindera sericea (Siebold & Zucc.) Blume; 28 level III taxa, such as Botrychium japonicum (Prantl) Underw.; 22 level II taxa, including Hylomecon vernalis Maxim.; and 69 level I taxa, including Dryopteris erythrosora (D. C. Eaton) Kuntze. There are 37 invasive plants, including Rumex acetosella L. and Symphyotrichum pilosum (Willd.) G. L. Nesom.