• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권1호
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• pp.67-70
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• 2009

Purpose: This study presents the use of mini implants for fixed restoration and implant supported overdenture to enable the practitioner to overcome the anatomic obstacles of ridge width and narrow interdental space. Patients and methods: This study consisted of 9 patients who required single implants for one or two teeth replacement and 1 patient who required implant supported overdenture after mandiblectomy, iliac bone graft due to ghost cell tumor. The ages ranged from 29 to 70 years (mean 51). All patients were in good health. Clinical and radiographs were taken pretreatment, postoperatively, during rehabilitation, and at follow ups. Results: Total implant survival rate was 94.7%. One implant was removed due to its mobility as a result of bad bone quality (Type IV) and patient's carelessness (Heavy smoker). All patients except one reported complete satisfaction regarding to function, aesthetics, and phonetics. Radiographic follow up every 3months postoperatively showed success in achieving function and maintaining marginal bone level. Conclusion: Clinician can overcome both severe ridge deficiency and small interdental space with mini implant.

• 구강회복응용과학지
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• 제34권1호
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• pp.32-38
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• 2018

목적: 3.6 mm 이하 좁은 직경 임플란트의 일정 기간 생존율을 초기고정 값과 방사선학적 계측을 통해 분석해보고자 하였다. 연구 재료 및 방법: 24명의 환자에 식립된 직경 3.6 mm 이하, 길이 7 mm 이상의 38개의 임플란트를 조사하였다. 식립된 임플란트의 platform 직경, body 직경, 길이, 식립 부위 등을 확인하였고 식립 시 골유도재생술의 동반 시행 여부, 완성된 보철의 형태를 확인하였다. 초기고정 값은 임플란트 식립 직후 측정한 implant stability quotient (ISQ) 값을 확인하였고, 방사선 사진을 통해 식립된 임플란트의 근 원심 marginal bone level (MBL)을 측정하였다. 결과: 전체 임플란트의 생존율은 92.11% 이었고 ISQ값은 평균 66.26으로 나타났다. 생존한 임플란트의 MBL 변화는 평균 $0.14{\pm}0.31mm$를 나타내었다. Platform 직경이 body 직경보다 큰 임플란트 중 실패한 임플란트는 없었다. 결론: 좁은 직경의 임플란트는 좁은 직경의 치조제에 안정적인 치료 결과를 나타낸다 사료된다.

• 대한치과보철학회지
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• 제43권3호
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• pp.331-337
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• 2005

For a missing teeth, orthodontic treatment may be a better choice of treatment in comparison to a conventional prosthetic replacement such as FPD, resin bonded prosthesis in view of aesthetics, periodontal health and function. Occasionally after an orthodontic treatment, an insufficient space may occur. The mini-implant could be an alternative in situations of narrow ridge dimension, where conventional root form implant could be compromised. The aim of this clinical report is to describe how a space that could not be restored with a traditional root form endosteal implant was managed and to present a technique to achieve optimal anterior esthetics in single implant restoration.

• 한국통신학회논문지
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• 제22권1호
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• pp.81-88
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• 1997

Wavelength tunable, narrowbandwidth wvelength filters in compound semiconductor have been modeled, fabricated, and characterized. In order to obtain a narrow bandpass characteristics at 1.55.$\mu$m, a highly asymmertrical directional coupler structure composed of a strongly guided ridge waveguide and a weakly guided strip-loaded waveguide was used. The optimized filter structure modeling has been obtained by using the spectral index method, effective index method, and the coupled mode theory. Operation at a center wavelength a 1.537.mu.m with a bandwidth of 1.8nm and transfer efficiency of 50-70% is experimentally achieved. For the purpose of center wavelength tuning, the carrier injection in p-n diode structure has been theoretically investigated. It has been found that the tuning range of nanometer can be easily obtained by moderate amount carrier injection. We also found that the bandwidth becomes broad as the center wavelength tuning increases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권4호
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• pp.325-330
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• 2010

Introduction: Mini-implant system is applicable to areas of narrow space and area requiring temporary loading support. The purpose of this study was to evaluate the clinical outcome of a mini-implant system as well as the application of mini-implant system in the dental clinical field. Materials and Methods: The patients who had been operated from Jan 2007 to Dec 2007 in the four dental facility including Seoul National University Bundang Hospital were enrolled. To evaluate the factors associated with the clinical outcome, the patients were classified according to gender, age, area of surgery, type of implant, diameter and length of the implant, and the purpose of the mini-implant system application. Results: From 147 implants, only three implants failed, one of them was for temporary loading. There were no serious surgical or prosthetic complications in this study. Conclusion: An analysis of the preliminary data revealed a satisfactory clinical outcome. However, more long-term evaluation of narrow ridge type as well as the patient’s satisfaction on the use of a provisional type mini-implant system is needed.

• 대한심미치과학회지
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• 제27권2호
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• pp.97-104
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• 2018

하악 전치부는 다른 구강 내 영역에 비해 높은 임플란트 성공률과 더 나은 접근성을 갖고 있다. 비록 부적절한 드릴링으로 인한 설측 피질골 천공 가능성과 설동맥 손상으로 인한 출혈 가능성이 있더라도 다른 부위와 비교했을 때 주요 해부학적 구조물이 적기 때문에 상대적으로 안전하다. 또한 상악 전치부와 비교했을 때 환자들이 심미적으로 덜 민감한 부위이다. 그러나 좁은 협설측 치조골 폭 때문에 이상적인 임플란트 식립 위치로의 식립은 상악 전치부만큼 어렵다. 이러한 하악 전치부에서 일체형 임플란트는 매우 유용한 치료방법이다. 하악 전치의 해부학적 치근형태와 얇은 치조골을 고려할 때, 임상적으로 3mm보다 큰 직경의 임플란트 식립은 어렵다. 본 증례는 하악 전치부 무치악 부위에서 일체형 임플란트의 식립과 즉시 부하를 동반하여 심미적인 보철물을 구현한 경우이다.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.291-316
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• 1993

Restorative procedures can lead to tooth fracture due to the relatively small amount of the remaining tooth structure. It is essential to prevent fractures by having a clear concept of the designs for cavity preparations. Among the several parameters in cavity designs, profound understanding of isthmus width factor would facilitate selection of the appropriate cavity preparation for a specific clinical situation. In this study, MO amalgam cavity were prepared on maxillary first premolar and filled with amalgam. Three dimensional, model with 1365 8-node brick elements was made by serial photographic method. In this model, isthmus was varied in width at 1/4, 1/3, 1/2 and 2/3 of intercuspal width and material properties were given for three element groups, i.e., enamel, dentin and amalgam. A load of 500 N was applied vertically on amalgam and enamel. In case of enamel loading, 2 model (with and without amalgam) was compared to consider the possibility of play at the interface between tooth material and amalgam. These models were analyzed with three dimensional finite element method. The results were as follows: 1. The stress was concentrated on the facio-pulpal line angle and distal marginal ridge of the cavity. 2. With the increase of the isthmus width, the stress spread around the facio-pulpal line angle and the area of stress concentration moved toward the proximal box. 3. In case of narrow isthmus width, the initiation point of crack would be in the area of isthmus corner of the cavity, and with the increase of the isthmus width, it would move toward the proximal box and at the same time the possibility of crack increase at the distal marginal ridge. 4. The direction of crack progressed outward and downward from the facio-pulpal line angle, and with the increase of the isthmus width, it approximated vertical direction. At the marginal ridge, it occurred in vertical direction. 5. It would be favorable to make the isthmus width narrower than a third of the intercuspal width, and to cover the cusp if isthmus width were wider than half of the intercuspal width. 6. It is necessary to apply the possibility of play to the finite element analysis.

• 환경생물
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• 제20권3호
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• pp.216-223
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• 2002

본 연구는 계룡산국립공원의 지류인 도덕봉과 백운봉의 산림식생을 대상으로 식물사회학적 방법에 의해 산림군락을 분류하고 이 지역의 식생 현황 파악과 국립공원관리에 필요한 기초자료를 제공하고자 하였다. 식물사회학적 방법으로 89개 조사구를 분석한 결과, 신갈나무군락, 졸참나무군락, 굴참나무군락, 소나무군락, 서어나무군락, 리기다소나무-곰솔군락으로 구분되었다. 신갈나무군락은 해발고가 가장 높고 경사가 급한 지역에 분포하였으며, 졸참나무군락은 해발고가 비교적 낮고 경사가 급한 지역에 분포하였다. 그리고 굴참나무군락은 신갈나무군락에 비해 해발고가 낮은 남사면의 건조한 지역에 분포하고 있었다. 소나무군락은 해발고가 비교적 높고 폭이 좁은 건조한 능선 부위에 분포하고 있으며, 서어나무군락은 주로 남사면 계곡부의 중부에 분포하고 있었다. 그리고 리기다-곰솔군락은 조림군락이다.

• 한국수산과학회지
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• 제52권6호
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• pp.696-701
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• 2019

Five specimens (839 - 1280 mm TL, Total length) of the dusky shark Carcharhinus obscurus, belonging to the family Carcharhinidae, were collected from the waters off Jejudo Island, Sinan, Namhae, Busan and Gangneung, Korea, during 2010-2019. Carcharhinus obscurus was similar to Carcharhinus brachyurus but was distinguished by the interdorsal ridge (present in C. obscurus vs. absent in C. brachyurus) and the shape of upper jaw teeth (broad in C. obscurus vs. narrow in C. brachyurus). In addition, 479 base-pair sequences in the mitochondrial DNA cytochrome c oxidase subunit I (COI) of our two specimens corresponded to those of C. obscurus (genetic distance, 0.000-0.003), but clearly distinguished from those of the Korean C. brachyurus (genetic distance, 0.03). We adopted the Korean name "Heuk-sang-eo" for Carcharhinus obscurus, after Kim and Ryu (2017).

• Parasites, Hosts and Diseases
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• 제41권2호
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• pp.107-111
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• 2003

The surface ultrastructure of Acanthotrema felis (Trematoda: Heterophyidae) adults, recovered from a kitten experimentally infected with the metacercariae, was observed using a scanning electron microscope. The worm was leaf-like, ventrally concave and covered with scale-like multi-pointed tegumental spines. The spines on the anterior surface were short but broad, and had 10-12 pointed tips. The cytoplasmic processes protruded around the spines, like pockets for the spines. The ventrogenital opening was crescent, or kidney-shaped, and had protuberances with minute spines on its surrounding tegument. The spines on the posterior surface were long, but narrow, with 6-8 pointed tips. The cytoplasmic processes on this tegument were ridge-like, and elevated along the row of the spines. The surface ultrastructure of A. felis is generally similar to that of other heterophyid flukes, but some features are characteristic, and may be of taxonomic and bio-ecological significance.