• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.461-471
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• 2006

In order to achieve a satisfactory esthetic result of periodontal surgery or implant in maxillary anterior area, periodontists must be aware of normal alveolar bone anatomy. The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 78(mean age : 25 yrs) periodontally healthy volunteers participated in this study. Two maxillary central incisor and one lateral incisor were selected to study. With minimal local anesthesia, gutta-percha cone inserted to labial gingival sulcus of selected teeth just after bone sounding with periodontal probe. Metal ball (4mm diameter) attached to palatal fossa of central incisor. Then, periapical radiograph was taken according to long cone paralleling technique. After film scan, labial alveolar bone profile reproduced along interproximal bone and apical ends of gutta-percha cones on computer screen. By utilizing computer program, the distance from height of interproximal bone to the labial bone crest in central incisor-central incisor and central incisor-lateral incisor area was measured and converted to real distance by using vertical length of metal ball on film. After measuring crown length & width of central incisor, the 10 individuals ranked lowest GW/L ratio (crown width/length ratio) and the 10 ranked highest were selected as having a long-narrow(group N), or a short-wide(group W) form of the central incisors. Means of the distance from height of interproximal bone to the labial bone crest of group N, W were calculated and compared by means of independent t-test. The results were as follows: 1. Mean distance from the height of the interproximal bone to the labial bone crest was $3.5{\pm}0.7mm$ between two central incisor, and $2.8{\pm}0.6mm$ between central and lateral incisor. 2. Mean GW/L ratio of group N was 0.57, and group W was 0.8. Mean distance from the height of the interproximal bone to the labial bone crest of group N was higher than group W in both measured area(measurements of group N, W were $3.9{\pm0.2mm$ and $3.5{\pm}0.2mm$ between two central incisor, $3.0{\pm}0.2mm$ and $2.8{\pm}0.2mm$ between central and lateral incisor), but there were no statistically significant differences when the groups were compared. Within the limits of the present study, there was a tendency that subjects with long-narrow teeth have more scalloped alveolar bone profile than subjects with short-wide teeth in upper anterior area, but no statistically significant differences were found.

• Restorative Dentistry and Endodontics
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• 제27권6호
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• pp.622-631
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• 2002

To understand the recent characteristics of the papers published in the Journal of Korean Academy of Conservative Dentistry(JKACD), All the papers in the JKACD of 1992 to 2001 were analyzed. A total of 513 papers were classified according to its type, fold and subject of the study, school and the number of authors, references, and written language. The results were as follows ; 1 According to the type of the paper, 506(98.6%) were original articles, 3(0.6%) were review articles, and 4(0.8%) were case reports. 2. Anual proportion of papers in the fold of operative dentistry was similar to that of endodontics 3. In the field of operative dentistry, esthetic restorative materials and bonding to tooth constituted major subjects of the studies. In the field of endodotics, pulp biology was prominent and canal shaping, endodontic microbiology and canal obturation were steadily reported. 4. According to author's school, similar number of papers were published in the field of operative den tistry and endodontics in general. However, some schools showed preponderances. 5. Most studies were done by two or more authors. Studies published by two authors were most 6. Fifty(9.7%) papers were done in collaboration with workers of the other field. 7. Average number of references cited in the papers was 41.2, including domestic references of 1.8. 40.7% of the papers was shown to cite no domestic papers at all. 8. Twenty-eight(5.5%) papers were written in English, with increasing ratio.

• 한국건설순환자원학회논문집
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• 제6권3호
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• pp.69-78
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• 2011

최근 콘크리트제품에 대한 고급화, 고품질화 및 고강도화 등의 추구로 변화함에 따라 구조물의 미적효과와 전시 목적의 제품 고급화를 위해 반투명 콘크리트를 제작하였다. 본 연구에서는 반투명 콘크리트의 제조기법 개발을 통해 다양한 형상의 블록 제조방식을 소개하고, 또한 반투명 콘크리트의 물성 평가와 더불어 경제적인 반투명 콘크리트 제조를 위해 무기혼화재인 고로슬래그와 플라이애시의 활용 및 유리알갱이의 적용방안에 대해 검토하였다. 물성평가 결과, 반투명 콘크리트 블록의 28일 압축강도는 32.2MPa이고 탄성계수와 푸아송비는 일반 콘크리트 블록에 비해 증가되어 압축을 받는 부재일 경우 일반 콘크리트 구조물과 같이 구조적 용도로도 사용이 가능하다는 것을 알 수 있었다. 시멘트 대체재로써 플라이애시 적용하였을 때 동일 양의 광섬유를 포함한 반투명 콘크리트 블록의 28일 강도의 85~96%의 값을 보였으며, 고로슬래그 미분말을 적용하였을 때에는 82~96%의 값을 보였다. 또한, 광섬유대체재로서 유리알갱이를 적용한 결과, 빛의 투과효과가 전혀 나타나지 않아 대체효과가 전혀 없는 것으로 나타났다.

• 대한소아치과학회지
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• 제34권3호
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• pp.519-525
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• 2007

과잉치는 정상 치판의 과도한 증식의 결과로 발생하고, 주로 상악 전방부에서 많이 발견되며 이것을 정중과잉치라 칭한다. 정중과잉치의 존재 시 영구 전치의 위치 이상, 정중이개, 낭종의 형성, 구강 및 비강 내로의 맹출 등과 같은 다양한 문제가 존재하게 되므로 발거하는 것이 일반적이다. 본 증례는 외상으로 인해 편측 상악 중절치를 조기에 상실하였고, 매복된 상악 정중과잉치를 가지고 있는 9세 8개월된 남아로, 정중과잉치를 상실된 상악 중절치 부위에 자가이식한 후 보철적으로 수복하여 치조골 흡수를 막고 심미적인 수복을 도모한 증례이다. 이 증례에서 과잉치는 총 길이 14mm로 지대치로 사용하기에는 크기가 작고 치관/치근 비율도 좋지 않아 예후가 불량할 것으로 예상하였으나, 시술 후 8개월의 관찰 기간 동안 양호한 결과를 나타내어 이에 보고하는 바이다.

• Archives of Plastic Surgery
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• 제47권5호
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• pp.451-459
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• 2020

Background For volar soft tissue defects of the proximal interphalangeal (PIP) joint, free flaps are technically challenging, but have more esthetic and functional advantages than local or distant flaps. In this study, we compared the long-term surgical outcomes of arterial (hypothenar, thenar, or second toe plantar) and venous free flaps for volar defects of the PIP joint. Methods This was a single-center retrospective review of free flap coverage of volar defects between the distal interphalangeal and metacarpophalangeal joint from July 2010 to August 2019. Patients with severe crush injuries (degloving, tendon or bone defects, or comminuted/intra-articular fractures), thumb injuries, multiple-joint and finger injuries, dorsal soft tissue defects, and defects >6 cm in length were excluded from the study, as were those lost to follow-up within 6 months. Thirteen patients received arterial (hypothenar, thenar, or second toe plantar) free flaps and 12 received venous free flaps. Patients' age, follow-up period, PIP joint active range of motion (ROM), extension lag, grip-strength ratio of the injured to the uninjured hand, and Quick Disabilities of Arm, Shoulder & Hand (QuickDASH) score were compared between the groups. Results Arterial free flaps showed significantly higher PIP joint active ROM (P=0.043) and lower extension lag (P =0.035) than venous free flaps. The differences in flexion, grip strength, and QuickDASH scores were not statistically significant. Conclusions The surgical outcomes of arterial free flaps were superior to those of venous free flaps for volar defects of the PIP joint.

• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2008년도 춘계 학술발표회 논문집
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• pp.66-69
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• 2008

본 연구는 도로 상부에 휴식과 통행이 가능한 공간을 조성하여 녹지 및 휴게 공간을 확보하고 각 구역간의 연결성 및 접근성을 높일 수 있는 장 스팬 구조의 처짐의 거동을 해석하는 것을 목표로 한다. 이러한 장 스팬 구조의 경우, 부재의 크기를 결정할 때 도심 미관과 하부의 차량소통을 고려하여야 한다. 그 결과 부재의 크기가 세장해지는 결과를 가져오게 되며 이는 구조물의 과다 처짐을 유발할 수가 있다, 여기에서는 부재의 크기 제한과 구조물의 과다 처짐을 방지하기 위하여 구조물 하부에 언더텐션을 적용한 후, 그 효과와 처짐 거동에 대하여 비교 분석하였다. 언더텐션이란 상부에서의 하중을 하부 케이블의 인장력을 이용하여 그 하중을 양 단부로 전달하는 시스템을 말하며, 케이블의 크기와 개수, 포스트의 개수와 크기 및 간격에 따라서 효과가 다르게 나타날 수 있다. 따라서 본 연구에서는 케이블의 크기와 개수, 포스트의 개수와 크기 및 간격을 변수로 하여 장 스팬 구조의 처짐 거동을 비교하였다. 하중은 활하중과 고정하중이 평면에 재하되는 것을 기본으로 가정하였으며, 해석결과는 상용 프로그램인 마이더스(MIDAS)를 이용하여 언더텐션의 효과를 처짐에 맞추어 비교 검토하였다.

• 대한소아치과학회지
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• 제33권3호
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• pp.504-509
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• 2006

소아치과는 소아와 청소년의 구강상태에 대하여 보존, 교정, 치주, 외과치료 등 다방면의 치료를 복합적으로 시행한다는 점에서 타분야와 구분된다. 초창기의 소아치과학은 유치와 영구치의 우식의 치료, 발치 등에 국한되었으나, 최근에는 교정, 소 수술, 심미, 예방치료 등으로 진료의 범주가 확대되고 있다 2005년 11월 현재 소아와 청소년을 대상으로 하는 개인치과에서 근무하는 치과의사 50명을 대상으로 설문지를 발송하고 회송된 설문지 21매를 토대로 진료현황을 분석한 결과 다음과 같은 결론을 얻었다. 1. 일주일 간 평균적으로 진료하는 환자의 수는 82.4명이었고, 각 환자당 평균적으로 치료받는 치아의 수는 2.35개였다. 2, 전체 치료 중 예방치료가 15.7%, 수복치료가 55.7%, 치수치료가 15.6%, 외과치료가 10.5%, 교정치료가 2.4%를 차지하였다. 3. 수복치료 중 아말감이 3.8%, 글래스 아이오노머가 5.5%, 복합레진이 63.0%, 스테인레스 기성금관이 277%를 차지하였다.

• 대한치과보철학회지
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• 제44권1호
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• pp.85-102
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• 2006

Statement of problem: Currently, there are some 20 different geometric variations in implant/abutment interface available. The geometry is important because it is one of the primary determinants of joint strength, joint stability, locational and rotational stability. Purpose: As the effects of the various implant-abutment connections and the prosthesis height variation on stress distribution are not yet examined this study is to focus on the different types of implant-abutment connection and the prosthesis height using three dimensional finite element analysis. Material and method. The models were constructed with ITI, 3i TG, Bicon, Frialit-2 fixtures and solid abutment, TG post, Bicon post, EstheticBase abutment respectively. And the super structures were constructed as mandibular second premolar shapes with 8.5 mm, 11 mm, 13.5 mm of crown height. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the central pit of an occlusal surface. von Mises stresses were recorded and compared in the crowns, abutments, fixtures. Results: 1. Under the oblique loading, von Mises stresses were larger in the crown, abutment, fixture compared to the vertical loading condition. 2. The stresses were increased proportionally to the crown height under oblique loading but showed little differences with three different crown heights under vertical loading. 3. In the crown, the highest stress areas were loading points under vertical loading, and the finish lines under oblique loading. 4. Under the oblique loading, the higher stresses were located in the fixture/abutment interface of the Bicon and Frialit-2 systems compared to the ITI and TG systems. Conclusions: The stress distribution patterns of each implant-abutment system had difference among them and adequate crown height/implant ratio was important to reduce the stresses around the implants.

• Journal of Periodontal and Implant Science
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• 제51권2호
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• pp.88-99
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• 2021

Purpose: Direct intraoral scanning and superimposing methods have recently been applied to measure the dimensions of periodontal tissues. The aim of this study was to analyze various correlations between labial gingival thickness and underlying alveolar bone thickness, as well as clinical parameters among 3 tooth types (central incisors, lateral incisors, and canines) using a digital method. Methods: In 20 periodontally healthy subjects, cone-beam computed tomography images and intraoral scanned files were obtained. Measurements of labial alveolar bone and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0-5 mm from the alveolar crest on the superimposed images. Clinical parameters including the crown width/crown length ratio, keratinized gingival width, gingival scallop, and transparency of the periodontal probe through the gingival sulcus were examined. Results: Gingival thickness at the alveolar crest level was positively correlated with the thickness of the alveolar bone plate (P<0.05). The central incisors revealed a strong correlation between labial alveolar bone thickness at 1 and 2 mm, respectively, inferior to the alveolar crest and the thickness of the gingiva at the alveolar crest line (G0), whereas G0 and labial bone thickness at every level were positively correlated in the lateral incisors and canines. No significant correlations were found between clinical parameters and hard or soft tissue thickness. Conclusions: Gingival thickness at the alveolar crest level revealed a positive correlation with labial alveolar bone thickness, although this correlation at identical depth levels was not significant. Gingival thickness, at or under the alveolar crest level, was not associated with the clinical parameters of the gingival features, such as the crown form, gingival scallop, or keratinized gingival width.

• Journal of Chest Surgery
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• 제55권6호
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• pp.462-469
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• 2022

Background: Carotid endarterectomy (CEA) is used to treat carotid stenosis, which is associated with cerebral infarction and may result in neurologic deficits such as stroke, transient ischemic attack (TIA), and local nerve injury. To decrease surgery-related complications and improve patient satisfaction with esthetic outcomes, efforts have been made to minimize incision size instead of using a standard longitudinal incision. Methods: We performed a retrospective analysis of 151 cases of CEA, of which 110 used conventional incisions and 41 used high mini-skin incisions (HMIs), from March 2015 to December 2021 at a single institution. Short-term (30-day) postoperative results were evaluated for rates of mortality, stroke, TIA, and cranial/cervical nerve injuries. Risk factors for nerve injury were also assessed. Results: The HMI group showed significantly (p<0.01) shorter operative and clamp times than the conventional group. The HMI group also had significantly shorter incision lengths (5.3±0.9 cm) than the conventional group (11.5±2.8 cm). The rates of stroke, TIA, and death at 30 days were not significantly different between the 2 groups. There was no significant difference in the rate of cranial and cervical nerve injuries, and all injuries were transient. A high lesion level (odds ratio [OR], 9.56; 95% confidence interval [CI], 3.21-28.42; p<0.01) and the clamp time (OR, 1.07; 95% CI, 1.03-1.12; p<0.01) were found to be risk factors for nerve injuries. Conclusion: Use of the HMI in CEA for carotid stenosis was advantageous for its shorter operative time, shorter internal carotid artery clamp time, reduced neurologic complications, and improved esthetics.