• Proceedings of the KACD Conference
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• 2001.05a
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• pp.243-244
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• 2001

Root resorption is conventionally divided into internal and external varieties. Internal resorption occurs where there is loss of the internal wall of the root canal. and is usually associated with a localized area of necrotic pulp(Trope '||'&'||' Chivian 1984). External resorption occurs where there is loss of the external surface of the root and the resorption may be either transient or progressive(Tronstad 1988). External inflammatory resorption usually occurs following damage to the periodontal ligament or where there is communication between the periodontal ligament and a necrotic pulp. via open dentinal tubules or accessory canals. This type of resorption is usually progressive until root canal treatment is instituted (Barclay 1993).

• Magazine of the Korea Concrete Institute
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• v.4 no.2
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• pp.103-110
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• 1992

본 연구는 인성지수에 의하여 섬유보강 콘크리트의 인성을 평가하는 기존의 여러 가지 방법을 검토하는, 하중-처짐곡선에서 초기균열시까지의 여러 가지 다른 곱으로 나타내어지는 방법의 불합리성을 지적하였다. 이를 위하여 본 연구에서는 유효인성이라고 부르는 새로운 방법을 강섬유 보강콘크리트의 인성을 평가하는데 제안하였다. 이는 초기균열을 가진 3점 휨강도 시험에 의한 하중-처짐곡선에서 지간의 1/150까지의 면적을 ligament면적으로 나눈값으로 나타낸다. 이 방법을 사용하여 강섬유 보강 고강도 콘크리트 인성특성을 검토한 결과 기존의 방법보다 더 효과적으로 인성을 평가할 수 있었다.

• Journal of the Korean Orthopaedic Association
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• v.55 no.4
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• pp.305-310
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• 2020

The review provides updated concepts regard to the anatomy of the anterior cruciate ligament (ACL) footprints. The concept of anatomical ACL reconstruction, in which the graft is placed in the native ACL insertion area, has been introduced. However, there is still no consensus on the anatomical positioning of the femoral and tibial tunnel. In this study, authors review and update the literature regarding the tunnel position for anatomical ACL reconstruction.

• The korean journal of orthodontics
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• v.44 no.5
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• pp.263-267
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• 2014

Objective: To three-dimensionally elucidate the effects of occlusal hypofunction on the periodontal ligament and alveolar bone proper of rat molars by micro-computed tomography (micro-CT). Methods: Occlusal function in the molar area was restricted by attaching an anterior bite plate on the maxillary incisors and a metal cap on the mandibular incisors of 5-week-old male Wistar rats for 1 week. The periodontal ligament space and alveolar bone proper around roots of the mandibular first molar were assessed by histology and micro-CT. Results: The periodontal ligament space was narrower and the alveolar bone proper was sparser and less continuous in the hypofunction group than in the control group. Further, both the volume of the periodontal ligament and the volumetric ratio of the alveolar bone proper to the total tissue in the region of interest were significantly lower in the hypofunction group (p < 0.05). Conclusions: Occlusal hypofunction induces atrophic changes in the periodontal ligament and alveolar bone proper of rat molars.

• Anatomy and Cell Biology
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• v.56 no.2
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• pp.191-199
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• 2023

The anterior cruciate ligament (ACL) is mostly damaged in sporting activities. To reconstruct the damaged ACL, a patellar tendon (PT) is often the most preferred graft due to its fast healing and bone integration i.e. bone-patellar tendon-bone graft. Suitability of the PT often depends on the morphometric profile of the tendon. This study reported on the harvestable surface area (SA) of the tendon using a simple tracing method. The PT of 79 adult formalin-fixed cadavers of South Africans of European Ancestry were dissected, and the margins of the PT were traced on a wax paper before the tracings were scanned. The SA, straight proximal width (SPW), curved proximal width (CPW), straight distal width (SDW), curved distal width (CDW) and length of tendon (LOT) from the digitized image of the PT was measured. In addition, the length of the lower limbs was measured to normalize the measurements. The results showed no significant side differences, and the measurements were not sexually dimorphic. A strong correlation was reported for SA vs. LOT, SPW vs. CPW and SDW vs. CDW for both sexes and sides. The presented morphological profile provides additional information on the usability of the graft and with respect to healing and recovery.

• Composites Research
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• v.25 no.6
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• pp.236-240
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• 2012

The purpose of this study was to investigate the feasibility on the detection of dental composite delamination using a lock-in thermography method. Amplitude and phase images of detected thermal signals were analyzed according to the lock-in frequencies. At a lock-in frequency of 0.05 Hz, the ligament thickness of 0.5 mm in the specimen exhibited the highest amplitude contrast between defective area and sound area. For ligament thicknesses of 1 mm and 1.5 mm, delamination detection was possible at 0.025 Hz and 0.01 Hz through the amplitude differences. At lock-in frequencies of 0.006 Hz and 0.01 Hz, ligament thickness 0.5 mm exhibited the highest phase contrast. For ligament thicknesses of 1 mm and 1.5 mm, the phase contrast exhibited possible detection of delamination at 0.006-0.1 Hz.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.539-543
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• 2018

Telometer is a supplementary filming device that improves the image quality and minimizes the motion unsharpness by enhancing the reproducibility of diagnostic images because it applies constant pressure (force) to the affected area. The stress-radiogram which is widely used to provide the o-bjective quantitative stability of knee ligament is reported in literature as the most suitable method to evaluate the stability of ligament and it is advised to use the Telometer. In order to evaluate the image reproducibility of the Telometer, the collateral ligament which is the most vulnerable among the ligaments consisting of the knee joint, the stress-radiogram was executed in the order of the Telometer, the push pull gauge and the conventional stress radiogram. Then, SPSS (Statistical Package for the Social Science) for Windows 22.0 was used for comparison and evaluation. According to the results of comparison and evaluation, the standard errors and standard deviations became smaller in the order of the Telometer, the push pull gauge, the conventional stress radiogram while the image reproducibility was higher in the order of the Telometer, the push pull gauge, the conventional stress radiogram. Therefore, it is considered that the use of the TELOS for stress-radiogram would enhance the quality of patient diagnostic images and the work performance of radiologists.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.45-48
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• 2001

The anterior horn of the medial meniscus is attached to the anterior surface of the tibia. The anterior horns of the medial and lateral menisci are connect with the transverse ligament. The posterior horn of the medial meniscus is firmly attached to the posterior aspect of the tibia just anterior to the insertion of the posterior cruciate ligament. The authors incidentally found an anomalous insertion of posterior horn of medial meniscus into the anterior horn area during arthroscopic examination in the symptomatic knee joint, which had been ruptured anterior cruciate ligament, and report with literature review.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.261-266
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• 2014

Objective : With the increased use of interspinous spacers in the treatment of lumbar stenosis, knowledge of the geometry of the interspinous space is important. To prevent dislodgment of an interspinous spacer, the accurate depth and width of the interspinous space needs to be established to facilitate the best intraoperative selection of correct spacer size. Methods : To determine the depth and width of the interspinous space, two methods are available which utilize plain film and magnetic resonance imaging (MRI). Data analysis of the interspinous depth and width was undertaken in 100 patients. Results : The standard deviations were variable, since skin thickness (zone 1) was altered by sex and age. The difference in the zone 1 distance between adjacent interspinous processes varied according to gender (p<0.05), but was not influenced by age [p=0.32 by analysis of variance between groups (ANOVA)]. Zone 2, the supraspinous, and zone 3, the interspinous ligament depths, comprise the operative working area during insertion of an interspinous spacer. There were no differences with regard to gender or age (p>0.05). For zones 6 and 7, the interspinous distances at the narrowest and widest points, respectively, were found to decrease with the aging process, but the decrease was not statistically significant. There were no differences with regard to gender (p>0.05). Conclusion : This study provides additional information on the interspinous space. This statistical data are valuable for use in the design of interspinous spacers.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.823-837
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• 2005

The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and enamel matrix protein used in conjunction with xenograft. compared to a control group with regards to bone regeneration at the grade III furcation area in beagle dogs. Control group was treated with bovine derived bone $powder(Biocera^{(R)})$, and experimental I group was treated with bovine derived bone powder and Platelet-rich plasma and experimental II group was treated with bovine derived bone powder and Enamel matrix $protein(Emdogain^{(R)})$. The regeneration rate of bone formation was observed and compared histopathologically at 2. 4, and 8 weeks after surgery. The results were as follows: 1. In control group and both experimental groups. inflammatory cells were observed but, new bone formation wasn't. 2. In control group, new cementum on the notch was found in 4 weeks, less mature periodontal ligament when compared to that of experimental group was found and cementum formation was great but, regeneration couldn't be seen in 8 weeks. 3. Experimental I group. new bone formation in the area adjacent to alveolar bone and graft material surrounded by more dense connective tissue were found in 4 weeks. New bone formation up to crown portion was found and periodontal ligament was aligned functionally and cementum more mature. 4. Experimental II group, new bone formation was found under the defect area in 4 weeks and new bone formation around graft material in 8 weeks, too, and there were a number of fibroblasts, blood vessels, acellular cementum, which was less mature when compared to that of experimental I group, and dense collagen fiber like which normal periodontal ligament has in periodontal ligament of experimental II group in 8 weeks. 5. As a result of histologic finding, bone formation rate were 18.0${\pm}$7.87%(control group), 34. 05${pm}$7.25%(experimental I group), 19.33 ${pm}$5.15%(experimental II group) in 4 weeks and 21.89${pm}$1.58%(control group), 38.82${pm}$3.2(experimental I group), 37.65${pm}$9.22%(experimental II group) in 8 weeks. 6. Statistically significant ratio of bone formation was observed in experimental I group in 4 weeks and in experimental II group in 8 weeks. When experimental I group was compared to experimental II group, the ratio of bone formation in experimental I group was higher than that in experimental II group in 4 weeks(p<0.05). This results suggest that platelet-rich plasma showed more new bone formation than enamel matrix protein within 4 weeks. And use of enamel matrix protein in the treatment of periodontal bone defects starts to enhance regeneration after 8 weeks in beagle dogs.