• 한국임상수의학회지
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• 제16권1호
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• pp.57-64
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• 1999

It was performed to evaulate the effects of occlusion of mandibular gland and sublingual gland on the mandibular gland in dogs. The occlusion of mandibular gland and sublingual gland was induced by ligature in clinically normal dogs, and ultrasonograpic appearance, hematological changes and histological changes of the mandibular gland were observed daily during 6 days. The results were as follows. 1. The length, width, circumference and area of the mandibular gland in clinically normal dogs were 25.1 mm, 8.4 mm, 56.4 mm and 163.0 $\textrm{mm}^2$ in the left, and 23.4 mm, 8.0 mm, 53.3 mm and 141.6 $\textrm{mm}^2$in the right. 2. The length, width, circumference and area of the mandibular gland were gradually increased after ligature of the salivary duct, and revealed maximum values, as 33.4 mm, 10.9 mm, 73.0 mm and 287.2 $\textrm{mm}^2$, respectively, at 24 hours after ligature, and returned to normal size at 3 days after ligature. 3. The size of the opposite mandibular gland without ligature was also gradually increased until 24 hours, and returned to normal size at 3 days, similar to the changes of the mandibular gland with ligature. 4. There were no significant changes after ligature of the salivary duct in hematological findings. 5. In histopathological findings, the major of glandular alveoli was enlarged at 24 hours after ligature of the salivary duct, and neutrophils and monocytes were infiltrated at 6 days after ligature.

• 대한치과교정학회지
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• 제21권3호
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• pp.543-560
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• 1991

Practitioners are aware of the presence of friction between bracket system and archwire during sliding movement of teeth. Clinically a mesiodistally applied force must exceed the frictional force to produce a tooth movement. The objective of this study were to determine, on a dry condition, changes in magnitude of friction with respect to load, 3rd order inclination (Torque), archwire materials and ligature type. Three wire alloys (Stainless Steel, TMA, NiTi) in two wire sizes (.016, .016x, .022 inch) were examined respect to two bracket system (Straight, Standard), and two ligature type (Metal, Plastic ligature) at three levels of load (100g, 150g, 200g). The results were as follows; 1. Frictional resistance was found to increase with increasing load for S.S., TMA, NiTi. 2. The straight bracket system was exhibited more frictional force than standard bracket system for .016x, .022 S.S. tightly ligated metal ligature. But, torque difference did not increase friction for loose metal ligature & plastic ligature. 3. Regardless of the ligature type, torque and load, stainless steel wire sliding against stainless steel exhibited the lowest friction, and TMA sliding against stainless steel exhibited the highest friction. 4. The loose stainless steel ligature generated lower frictional resistance than plastic ligature in all experimental groups. 5. The following factors affected friction in decreasing order; wire material ligature type, and load.

• Journal of Periodontal and Implant Science
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• 제43권4호
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• pp.147-152
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• 2013

Purpose: An animal periodontitis model is essential for research on the pathogenesis and treatment of periodontal disease. In this study, we have introduced a lipopolysaccharide (LPS) of a periodontal pathogen to the alveolar bone defect of experimental animals and investigated its suitability as a periodontitis model. Methods: Alveolar bone defects were made in both sides of the mandibular third premolar region of nine beagle dogs. Then, the animals were divided into the following groups: silk ligature tied on the cervical region of tooth group, Porphyromonas gingivalis LPS (P.g. LPS)-saturated collagen with silk ligature group, and no ligature or P.g. LPS application group as the control. The plaque index and gingival index were measured at 0 and 4 weeks postoperatively. The animals were then euthanized and prepared for histologic evaluation. Results: The silk ligature group and P.g. LPS with silk ligature group showed a significantly higher plaque index at 4 weeks compared to the control (P<0.05). No significant difference was found in the plaque index between the silk ligature group and P.g. LPS with silk ligature group. The P.g. LPS with silk ligature group showed a significantly higher gingival index compared to the silk ligature group or the control at 4 weeks (P<0.05). Histologic examination presented increased inflammatory cell infiltration in the gingival tissue and alveolar bone of the P.g. LPS with silk ligature group. Conclusions: An additional P.g. LPS-saturated collagen with silk ligature ensured periodontal inflammation at 4 weeks. Therefore, P.g. LPS with silk ligature application to surgically created alveolar bone defects may be a candidate model for experimental periodontitis.

• 대한융합한의학회지
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• 제4권1호
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• pp.29-36
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• 2022

Objectives : The purpose of this study was to investigate the anti-inflammatory effects of the aqueous extract of the steamed radix of Rehmanniae glutinosa (SRG) on periodontitis in ligature-induced rat model. Methods: To induce the periodontitis, ligature was placed around the lower first molar in rats. Rats were divided into 4 groups (n = 7), NL (non-ligatured and vehicle-treated), L (ligatured and vehicle-treated), SRG1 (ligatured and 1 mg/kg SRG-treated) and SRG100 (ligatured and 100 mg/kg SRG-treated). Vehicle or SRG solution was applied daily for 14 days and then all experimental rats were sacrificed. To examine the effect of SRG solution on periodontitis, the level of alveolar bone loss, cementum regeneration, gingival tissue degradation, and osteoclast cell numbers were analyzed. Results: Alveolar bone loss was inhibited in ligature-induced periodontitis rats treated with SRG treatment. Histopathological cementum was recovered in SRG1 and SRG100 groups. SRG extract inhibited gingival tissue degradation induced by ligature. In addition, the numbers of osteoclast cells were decreased by treatment SRG in periodontitis rats. Conclusion: Taken together, these results suggest that SRG have inhibitory effects against periodontitis. Therefore, the steamed radix of Rehmanniae glutinosa has may be a potential alternative for periodontitis.

• 대한치과교정학회지
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• 제28권2호
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• pp.329-341
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• 1998

간염이나 AIDS의 영향으로 멸균에 대한 관심이 높아지고 있으며, 교정 진료실에서도 교정용 플라이어의 멸균이 필요하게 되었다. 제조회사에서는 멸균 과정의 열이 교정용 플라이어에서의 야금학적 변화를 야기하지 않는다고 하지만 교정치과의사들은 가압 증기 멸균기나 대류식 건열 멸균기를 이용하여 반복적으로 멸균을 시행한 경우에 ligature cutter의 날이 쉽게 무디어져서 ligature cutter의 수명이 짧아진다는 것을 임상적 경험으로 알고 있다. 본 연구는 멸균과정이 교정용 플라이어의 물성에 미치는 영향을 알아보기 위하여 시행되었다. 본 연구에 사용된 교정용 플라이어는 멸균 과정을 견딜 수 있도록 개발했다고 주장하는 AEZ, Unitek과 Dentronix ligature cutter이었고, 멸균기는 대류식 건열 멸균기인 Bowmar RHT-1000과 Dentronix DDS-5000와 가압 증기 멸균기 인 Eschmann SES-2000이었다. 멸균하기 전과 200회와 400회 멸균한 후의 ligature cutter의 날 부위의 표면과 파단면의 상태는 주사 저자 현미경으로, 미세 조직은 광학 현미경으로 관찰하고, micro-Vickers와 Rockwell 경도 시험기로 경도를 측정하고, SEM-EDX로 조성 분석을 시행하여 다음과 같은 결론을 얻었다. 1. 주사 전자 현미경을 이용한 교정용 플라이어의 날 부위의 표면과 파단면의 관찰에 의하면 멸균 횟수의 증가에 따라서 표면 조직에서 검은 반점 형태의 부식 생성물의 수와 크기가 증가하는 경향이 있었으며 파단면의 관찰에서도 멸균 횟수의 증가에 따라서 전형적인 취성 파면인 벽개면의 분포율이 증가하는 경향이 있었다. 이러한 부식 현상과 금속 조직의 취성화로 기계적 특성이 저하될 것으로 사료되었다. 2. 광학 현미경을 이용한 미세 조직 사진의 관찰에서도 멸균 횟수의 증가에 따라서 Cr계 탄화물의 수와 크기가 증가하는 경향이 있었다. 이러한 금속 조직의 조대화에 따라서 기계적 특성이 저하된 것으로 생각되었다. 3. 교정용 플라이어의 날 부위의 경도는 멸균 횟수의 증가에 따라서 감소되었는데 경도의 감소는 멸균에 의한 부식생성물과 표면 조직의 변화에 따른 것으로 생각되었다. 4. SEM-EDX를 이용한 조성 분석의 결과에 의하면 AEZ과 Unitek ligature cutter는 Fe-Cr계 stainless steel이었고, Dentronix ligature cutter는 Co-Cr계 합금이었는데, 제조 회사에 따라서 금속의 조성은 달랐지만 멸균 전후의 비교에서는 큰 차이가 없었다. 5. 반복적으로 멸균을 하면서 실제 임상에서 사용한 교정용 플라이어의 날의 표면 조직을 주사 전자 현미경으로 관찰한 결과, 미세 균열을 발견할 수 있었다.

• ETRI Journal
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• 제40권6호
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• pp.774-787
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• 2018

Arabic handwriting segmentation and recognition is an area of research that has not yet been fully understood. Dealing with Arabic ligature segmentation, where the Arabic characters are connected and unconstrained naturally, is one of the fundamental problems when dealing with the Arabic script. Arabic character-recognition techniques consider ligatures as new classes in addition to the classes of the Arabic characters. This paper introduces an enhanced technique for Arabic handwriting recognition using the deep belief network (DBN) and a new morphological algorithm for ligature segmentation. There are two main stages for the implementation of this technique. The first stage involves an enhanced technique of the Sari segmentation algorithm, where a new ligature segmentation algorithm is developed. The second stage involves the Arabic character recognition using DBNs and support vector machines (SVMs). The two stages are tested on the IFN/ENIT and HACDB databases, and the results obtained proved the effectiveness of the proposed algorithm compared with other existing systems.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1401-1402
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• 2013

• International Journal of Oral Biology
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• 제41권4호
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• pp.225-230
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• 2016

Inflammation from chronic and acute infections of distal organs and tissues such as periodontitis is a risk factor for atherosclerotic vascular processes. Recently, a new model of atherosclerosis with vascular pathologies was developed in the Mongolian gerbil. In this study, we attempted to develop a model of ligature-induced periodontitis in gerbils and compared the characteristics of that periodontitis model with that in rats and mice. Each gerbil, rat, and mouse was randomly assigned to groups of control and periodontitis. A thread was placed around the cervix of the right and left first molars in the mandible with knots placed on the mesial side of each molar. At day 14 after the ligation, the animals were sacrificed and their mandibles were dissected. To measure alveolar bone loss along with inflammation, histopathological and micro-CT analyses were carried out. Gerbils showed tooth characteristics of deeper gingival crevice, longer cusp, longer root trunk and shorter root than those of rats and mice. The increased CEJ-ABC distance in distal and PDL area in furcation was also observed in ligated gerbils. An inflammatory response in the connective tissue under the junctional epithelium was also shown in all the animals. As a result, we confirmed the induction of periodontitis by ligature in the gerbils. We therefore consider the gerbil to be a useful model for investigating relationship between periodontitis and vascular disease in the same animal.

• International Journal of Ocean System Engineering
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• 제2권1호
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• pp.24-31
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• 2012

This paper introduce a technique for Word segmentation for the handwritten recognition of Urdu script. Word segmentation or word tokenization is a primary technique for understanding the sentences written in Urdu language. Several techniques are available for word segmentation in other languages but not much work has been done for word segmentation of Urdu Optical Character Recognition (OCR) System. A method is proposed for word segmentation in this paper. It finds the boundaries of words in a sequence of ligatures using probabilistic formulas, by utilizing the knowledge of collocation of ligatures and words in the corpus. The word identification rate using this technique is 97.10% with 66.63% unknown words identification rate.

• 대한치과교정학회지
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• 제28권5호
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• pp.813-823
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• 1998

마찰력은 치아이동시 활주이동부에 유해한 인자로 인식되어져 왔으나 치아이동에 저항하는 고정원에 있어서는 유리한 인자로 받아들여질 수 있다. 즉 마찰력이 작은 결찰법들을 이용하여 효과적인 치아이동을 도모하는 반면 마찰력이 큰 결찰법들을 이용하여 브라켓의 걸림에 의해 치아이동이 거의 일어나지 않게 하면 고정원을 강화할 수 있다. 인공타액하에서 시간경과에 따른 교정선과 브라켓 사이의 마찰력 변화, 탄성 모듈과 스테인레스 강 결찰선을 이용하여 각각 결찰양식을 달리 하였을 때의 마찰력 변화 그리고 결찰재의 재료를 달리 하였을 때의 마찰력 변화를 알아보기 위하여 .018"x.025" 슬롯의 상악 중절치용 standard edgewise twin 브라켓과 .017"x.022" 스테인레스 강 교정선을 탄성 모듈, .009" 스테인레스 강 결찰선 그리고 .012" 스테인레스 강 결찰선을 이용하여 다양하게 결찰하였다. 또한 통상적인 방법으로 결찰한 탄성 모듈 결찰군을 결찰 직후와 1주 간격으로 4주간 마찰력을 측정하여 다음과 같은 결과를 얻었다. ${\cdot}$탄성 모듈 whole tie시 시간경과에 따른 마찰력은 4주 경과시 가장 높았으나 3주, 2주, 1주, 결찰 직후간에는 통계학적으로 유의한 차이가 없었다 (p>0.n). ${\cdot}$탄성 모듈로 결찰시 마찰력은 twisting tie가 가장 높았고 double overlay tie, whole tie, half tie 순으로 나타났으나 twisting tie와 double overlay tie 간에는 통계학적으로 유의한 차이가 없었다 (p>0.05). ${\cdot}$스테인레스 강 결찰선으로 결찰시 half tie 군이 whole tie 군보다 낮은 마찰력을 보였으며 ligature tying plier로 결찰한 경우가 needle holder로 결찰한 경우보다 더 높았고 .012" 결찰선을 이용한 경우가 .009" 결찰선을 이용한 경우보다 더 높았다 (p<0.05). ${\cdot}$통상적인 방법으로 탄성 모듈과 스테인레스 강 결찰선을 이용하여 결찰한 경우 두 군간에 유의한 차이가 없었다(p>0.05).