• 구강회복응용과학지
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• 제36권4호
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• pp.232-241
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• 2020

목적: 이 연구는 정출된 자연치와 대합되는 임플란트에 발생하는 합병증과 그 양상에 대해 고찰하여 대합치 정출이 임플란트 합병증에 어떠한 영향을 미치는지에 대해 알아보고자 하였다. 연구 재료 및 방법: 조선대학교 치과병원에서 2006년부터 2018년 사이에 임플란트치료를 받은 환자 중에서 유지관리기간이 최소 5년 이상이면서 구치부 임플란트와 대합되는 자연치가 방사선 사진상으로 측정 및 비교 가능한 임플란트만을 선택하였다. 정출된 구치부 자연치와 대합되는 임플란트를 실험군인 Group 1 (n = 167: 상악(Group 1max) = 92, 하악(Group 1man) = 75)과 정출소견이 없는 구치부 자연치와 대합되는 임플란트를 대조군인 Group 2 (n = 656: 상악(Group 1max) = 272, 하악(Group 1man) = 384)로 분류하였다. 두 그룹 사이에 합병증의 발생빈도와 변연골 흡수에 대해 조사하였다. 결과: Group 1과 Group 2 사이에 합병증의 발생빈도는 통계학적으로 유의성이 있었다. 특히, 상악골의 치조골 소실 빈도와 치조골 소실 양이 통계적으로 유의한 차이를 나타내었다. 결론: 정출된 자연치는 대합되는 임플란트에 골흡수를 비롯한 합병증을 더 빈번하게 유발할 수 있다.

• 한국어류학회지
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• 제17권1호
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• pp.57-63
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• 2005

묵납자루에서 첫 번째 새궁 (gill arch)의 새파 수는 17-21개 (평균 19개) 정도로 적은 편이었으며, 새파의 길이는 280~430 (평균 $360{\pm}35)mm$이었다. 새파 간의 간격은 130~210 (평균 $160{\pm}15)mm$이었다. 인두치의 저작면은 안쪽이 파여 있는 형태로 제1치는 저작면의 발달이 매우 미약하나 제2, 3, 4, 5치의 저작면은 발달되어 있었다. 인두치와 새파는 생활사의 초기에 완전히 형성되었다. 소화관의 길이는 체장의 $3.63{\pm}0.12$배로 매우 길었으며, 식도에서 연결되어 항문쪽으로 길게 배열되다가 한번 접히고 시계방향으로 5회 정도 감긴 후 항문으로 연결되어 있었다. 묵납자루는 주로 식물성플랑크톤의 일종인 부착조류를 주로 섭식하였으며 그 중 규조류의 비율이 가장 높았고, 그 이외에 원생동물, 깔따구 유충, 식물의 씨앗, 육상곤충 등도 소화관 내용물에서 관찰되어 초식성이 강한 잡식성으로 볼 수 있었다.

• Animal Systematics, Evolution and Diversity
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• 제20권2호
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• pp.179-184
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• 2004

동해, 여수 및 영광에서 2001년 11월과 2002년 12월에 채집된 히드라해파리를 동정$\cdot$분류한 결과 노란무늬지상해파리 (Proboscidactyla flavicirrata) 보야 누스두겹관해파리 (Diphyes bojani) 및 바르그만머그관해파리 (Muggiaea bargmannae)가 한국미기록종으로 밝혀져 재기재하고 보고한다. 본 연구의 결과 지금까지 밝혀진 한국 해산 히드라해파리는 5목 15과 18종이 된다.

• 대한치과보철학회지
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• 제39권6호
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• pp.682-697
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• 2001

This investigation evaluated the fracture toughness($K_{IC}$) of eight currently available core materials, and relate the fracture toughness value to fractography analysis and surface characteristics using a atomic force microscope (AFM). Single-edge notched (SEN) test specimens (n=10) and compact tension (CT) test specimens (n=10) were prepared conforming to the ASTM Standard E-399 for a high copper amalgam, three composite core materials (Core-Max II, Core Paste, Bisfil Core), two reinforced composite core materials (Ti-Core, Ti-Core Natural), a resin-modified glass ionomer core material (Vitremer), and a conventional glass ionomer core material (Ketac-Molar). The specimens were tested with an Instron Universal Testing Machine. The maximum loads were measured to calculate the fracture toughness ($K_{IC}$). Thereafter, fracture surfaces of SEN specimens of each material were investigated for fractography analysis using scanning electron microscope. And, disc-shaped specimens with 1mm thickness were fabricated for each material and were investigated under AFM for surface morphology analysis. The results were as follows: 1. Bisfil Core showed the highest mean fracture toughness regardless of test methods. 2. For the tooth-colored materials, Ti-Core Natural exhibited the highest fracture toughness. 3. Ketac Molar showed a significantly low fracture toughness when compared with the amalgam and the composite resin core materials(p<0.05). 4. The fracture toughness values obtained with the single-edge notched test, except Ketac Molar, were higher than those obtained in the compact tension test. 5. SEM revealed that the fracture surface of high fracture toughness material was rougher than that of low fracture toughness material. 6. AFM revealed that the surface particles of the composite resins were smaller in size, with a lower surface roughness than the glass ionomer core materials.

• 대한치과보철학회지
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• 제33권1호
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• pp.130-143
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• 1995

The purpose of this study was to analyze the magnitude and distribution of stress using photoelastic model with the rigid connection using T-block attachment and non-rigid connection using key & keyway attachment. The vertical load of 16 Kg was applied on the central fossa of the tooth, the pontic and the implant, and the pattern and distribution under each condition was analyzed. The following results were obtained : 1. In case of vertical load on the central fossa of the implant, the stress was concentrated at the apex of the implant involving the mesial alveolar bone in both fixed partial denture with the rigid connection and that with the nonrigid connection and the stress concentration at the mesial cervical area of the implant was a little more in the nonrigid connection than in the rigid connection. 2. In case of vertical load on the central fossa of the pontic, the stress was concentrated at the apex of 2nd bicuspid in both 3 unit fixed partial denture with nonrigid connection and that with the rigid connection. The stress was more concentrated at the mesial alveolar bone of the implant, but the stress distribution at the natural teeth more favorable at the rigid connection than at the non-rigid connection in case of 4 unit fixed partial denture. 3. In case of vertical load of the central fossa of the 2nd bicuspid, much stress with 3 fringe order was observed at the apex of the 2nd bicuspid in the 3 unit fixed partial denture, but relatively even stress distribution was observed at the apex of the implant, the 1st and 2nd bicuspid, and the adjacent cuspid in the 4 unit fixed partial denture.

• Journal of Korean Dental Science
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• 제5권1호
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• pp.29-36
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• 2012

Purpose: To investigate the effects of anterior guidance (AG) change on the working (WCP) and non-working condylar paths (NWCP), and lower incisor path (LIP) using a splint with flat (FAG) or steep AG (SAG). Materials and Methods: The samples consisted of six young adult women (mean age=$23.5{\pm}3.3$ years). Inclusion criteria were skeletal Class I and normodivergent pattern, normal overbite/overjet, minimal slide from retruded cuspal position to intercuspal position, no temporomandibular disorder signs and symptoms, mutually protected occlusion, and minimal tooth wear. After the values of natural AG (NAG) were obtained as a reference for each patient, two types of splints ($15^{\circ}$ flatter and steeper than NAG) were made. After insertion of the splints with FAG or SAG, the WCP, NWCP, and LIP were recorded five times for each patient using an ultrasonic AQR (SAM, Munich, Germany) and statistical analysis was subsequently performed. Result: NAG exhibited postero-superior movement in the WCP and did not show a noticeable immediate side shift (ISS) or difference between the eccentric (EP) and returning paths (RP) in the NWCP. FAG was associated with an irregular and excessive WCP, an increase in ISS, and a difference between EP and RP in the NWCP. SAG showed minimal WCP movement and a decrease in the extent of difference between EP and RP in the NWCP. LIP showed significant differences in EP and in RP (P<0.001, all; FAG

• 한국치위생학회지
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• 제13권5호
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• pp.759-767
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• 2013

Objectives : The purpose of this study was to investigate the relationship between the oral health status of elderly people and their oral health-related quality of life. Methods : The subjects were the elderly people over 65 years old in Busan. A total of 479 elderly people participated in the study from general hospital, two research institutes, eight dental clinics, six welfare institutions, sixteen senior centers, and three nursing homes. The oral health impact profile-14 (OHIP-14) was used in the routine dental checkups of the elderly people. Results : Those who had no oral symptoms had a better oral health-related quality of life. Among the subfactors of the OHIP-14, significant differences were shown in functional limitation(p=0.001), physical pain(p<0.001), emotional discomfort(p<0.001), physical disability(p=0.001), emotional disability (p=0.001), social disability(p=0.005), physical handicap(p=0.003) and total OHIP-14(p<0.001). Those who had 18 sound teeth(natural teeth) or more had a better oral health-related quality of life. Among the subfactors of the OHIP-14, significant differences were shown in functional limitation(p<0.001), physical pain(p=0.007), emotional discomfort(p=0.019), physical disability(p=0.018), Emotional disability(p=.032) and total OHIP-14 (p=0.006). Conclusions : The results revealed a close relationship between oral health status and oral health-related quality of life. The number of sound teeth(natural teeth) and frequency of toothbrushing had a more positive influence. Therefore oral health programs for the elderly people can preserve remaining teeth. Toothbrushing is the best way to improve the quality of life in the elderly people.

• Annals of Geriatric Medicine and Research
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• 제22권4호
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• pp.194-199
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• 2018

Background: The aim of this study was to examine the correlation between the number of remaining natural teeth (NRT) and the appendicular skeletal muscle mass index (SMI) in older adults. Methods: This study was based on data from the 2008-2010 Korea National Health and Nutritional Examination Surveys. The participants were 2,378 older participants (984 men and 1,394 women) aged over 65 years. Survey dentists conducted oral health examinations, and ASM was measured using dual-energy X-ray absorptiometry. Results: The participants with $NRT{\geq}20$ had more ASM and SMI than those with NRT<20 in both sexes. SMI was correlated with NRT in men (r=0.018, p<0.001) and in women (r=-0.007, p<0.001). The positive correlation between the NRT and SMI remained significant in men even after adjusting for age, marital status, income, smoking, drinking, physical activity, protein intake, energy intake, calcium intake, body mass index, fasting blood glucose level, medications, and prostheses (${\beta}=0.011$, p=0.001). In women, the correlation disappeared after adjustment for smoking, alcohol, physical activity, protein intake, energy intake, calcium intake, marital status, income, fasting basal glucose, medication administration, and prostheses. Conclusion: This study showed a correlation between NRT and SMI in those ${\geq}65$ years of age in Korea. The relationship persisted in men, but not in women, even after adjusting for confounders.

• BMB Reports
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• 제52권6호
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• pp.409-414
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• 2019

Natural compounds isolated from medicinal herbs and plants have immense significance in maintaining bone health. Hydrolysable tannins have been shown to possess a variety of medicinal properties including antiviral, anticancer, and anti-osteoclastogenic activities. As a part of a study on the discovery of alternative agent against skeletal diseases, we isolated a hydrolysable tannin, 2-O-digalloyl-1,3,4,6-tetra-O-galloyl-${\beta}$-D-glucose (DTOGG), from Galla Rhois and examined the effect on osteoclast formation and function. We found that DTOGG significantly inhibited receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation by downregulating the expression of the key regulator in osteoclastogenesis as well as osteoclast-related genes. Analysis of RANKL/RANK signaling revealed that DTOGG impaired activation of $I{\kappa}B{\alpha}$ and p65 in the nuclear factor kappa-lightchain-enhancer of activated B cells (NF-${\kappa}B$) signaling pathway. Furthermore, DTOGG reduced bone resorbing activity of osteoclasts, compared to the vehicle-treated control. These results suggest that DTOGG could be a useful natural compound to manage osteoclast-mediated skeletal diseases.

• 구강생물연구
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• 제42권4호
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• pp.208-215
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• 2018

The purpose of this study was to identify the risk of dysphagia among patients that visited prosthodontics department, and evaluate the difference in risks arising from oral conditions and disease in order to preliminarily intervene the various influencing factors of dysphagia. A questionnaire was given to patients that were aged 65 years or older who visited the prosthodontics department between September to December 2017. The data was collected and analyzed using the t-test, $x^2-test$ and logistic regression analysis. The mean age of the patients was 75 years. Out of 300 patients, 206 patients (68.7%) had a risk of dysphagia. There were statistically significant differences between the -non-risk and risk groups, which included the number of natural teeth, total number of teeth including prosthesis, denture use, denture discomfort, number of tooth brushing, oral dryness, digestive system diseases, and musculoskeletal diseases. Among these, oral dryness was a risk factor while the total number of teeth, including natural teeth and prostheses, served as a protective factor. More than half of the elderly patients were at risk of dysphagia. Oral dryness is influenced by many factors and it should continuously be managed. Patients should fully recover their masticatory function by preserving the remaining teeth and compensating for the missing teeth. A dental practitioner should be fully aware of the risk of dysphagia in elderly patients and be able to intervene and offer proper patient health care in advance through treatment guidelines and education.