• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.646-650
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• 2007

The purpose of this study was to evaluate the prevalence of mesiodens at pediatric dental clinic in Anyang, Kyeong Gi-Do. From retrospective reviews of all patients who visited Kizwell pediatric dental clinic from 2003.4-2006.4, 241 patients (289 mesiodens) who were shown to have mesiodentes were examed by a periapical radiograph and a panoramic radiograph. The incidence of mesiodens was 3.42% and the ratio of male/female (184/57) was 3.2:1. The number of supernumerary teeth was one in 193 cases (80%), two in 48 cases (20%). The mesiodens was placed at left side more frequently and the most common shape was conical type (208, 78%). Of 289 mesiodens, the direction of the crown of the mesiodens was inverted in 156 (54%), in a normal direction in 104 (36%), in a horizontal direction with regard to the tooth axis in 29 (10%). Early diagnosis of the mesiodens allow the most appropriate treatment, often reducing the extent of surgery, orthodontic treatment and possible complications.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.490-493
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• 2000

Mesiodens are supernumerary teeth in the region of the maxillary central incisors, a condition which can lead to disorders of the dentition. Their presence may lead to disorders, such as delay in eruption of permanent teeth, development of dentigerous cysts, resorption of adjacent roots and eruption of a supernumerary tooth into nasal cavity. The optimal time for surgical intervention is controversial. Early diagnosis is important so as to enable good prognosis. Diagnosis primarily depends on x-ray films. Panorama film, occlusal film, periapical film have been used for detection of mesiodens. But, all of them have disadvantages. $SCANORA^{(R)}$ is a multimodal radiology system which utilizes the principles of narrow beam radiology and spiral tomography. Pre-programmed imaging procedure are provided for many dental situations An optional personal computer can be connected into the unit to help design the examination. We report two cases diagnosed by $SCANORA^{(R)}$. When compared with tube shift technique, it is simple and exact method of detecting mesiodens.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.391-399
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• 1997

Rapid palatal expansion(RPE) is a method of inducing the new bone formation in the palate by separation of the midpalatal suture, which can be done conveniently by placing heavy force across the maxillary dental arch. This experiment was undertaken to examine the histologic changes after RPE and during retention period. Four young adult dogs(a control dog, three experimental dogs) aged 4 to 6 months old were used for this experiment. Expansion screw($Hyrax^{\circledR}$, Dentarum Inc.) was delevered to the palate and fumed 180 degrees every morning and evening for 8 days, giving a total expansion of 7.2mm. A control dog was sacrified at the starting point of this study without any treatment and three experimental dogs were sacrified after RPE, 14-day retention, and 28-day retention in each. Thereafter, those samples were observed with hematoxylin-eosin(H-E) stain, ground section(Villanueva stain), alkaline phosphatase(ALP) stain, tartrate-resistant acid phosphatase(TRA) stain. The results were as followings: 1. After RPE, collagen fiber bundles were stretched along the midpalatal suture and few osteoblasts were flattened-inactive state and also, a little osteoid tissues was observed. Few multinucleated osteoclasts which had TRAP-positive activity in their cytoplasm were seen in horizontal section, whereas a few osteoclasts were seen in frontal section, especially in the nasal floor side of palatal bone. 2. After 14-day retention, collagen fiber bundles were stretched along the midpalatal suture and few osteoblasts which had ALP-positive activity in their cytoplasm were seen. Few multinucleated osteoclasts which had TRAP-positive activity in their cytoplasm were seen in horizontal section, whereas a few osteoclasts were seen in frontal section, especially in the nasal floor side of palatal bone. 3. After 28-day retention, collagen fiber bundles were arranged like those of control dog and osteoblasts which showed a lot of immature bone formation were cuboidal shape and exhibited ALP-positive activity in their cytoplasm. Few multinucleated osteoclasts which had TRAP-positive activity in their cytoplasm were seen in horizontal section, whereas a few osteoclasts were seen in frontal section, especially in the nasal floor side of palatal bone. According to the above results, the new bone formation after rapid palatal expansion was examined after 14-day retention and significantly increased after 28-day retention.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1987.05a
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• pp.16.1-16
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• 1987

양측성 정중위 성대마비는 양측 반회신경의 마비나 윤상피열연골관절이 염증이나 외상에 의하여 고정되는 경우에 발생하며 조기에 심한 호흡곤란을 초래하게 되므로 기관절개술을 요하게 되고, 또한 영구적인 기도확보를 목적으로 Woodman(1946), Orton(1948), Thornell(1959), Downey(1968)등의 여러 학자들에 의하여 다양한 방법으로 피열연골에 대한 수술법이 시도되어 왔다. 최근 10년간 본 교실에서 양측성 정중위 성대마비 7례, 양측성 윤상피열연골관절고정 2례에 대하여 endolaryngeal arytenoidectomy (Thornell's method) 6례 , extralaryngeal arytenoidectomy 3례 (Woodman's method l례, Downey's method 2례)를 각각 시행하여 비교적 좋은 성적을 거두었기에 이들을 비교 검토하여 문헌고찰과 함께 보고하는 바이다.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.17-28
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• 1997

To study the possibility of agricultural utilization of industrial wastewater sludge, the changes of the substances, such as temperature, pH, inorganic and organic matter, the form of nitrogen, fatty acid and the population number of microorganisms during composting periods were investigated. Temperature and $CO_2$ generation were the highest in the second day of composting peroids, and then were gradually fallen. And they were similar to room temperature after the sixth day of composting periods. C/N ratio was a little increased as time went by. pH value was not changed in early composting periods and then pH had been gradually decreased since it was rapidly increased. It was in the range of 8.7~8.8 in late composting periods. The contents of $P_2O_5$, $K_2O$, CaO, MgO and Fe were a little increased and that of ${SO_4}^{2-}$ was increased with 62~67% in late in comparing with early composting periods. The contents of ether extracted materials, water soluble polysaccharides, hemicellulose and cellulose were decreased but that of resins and lignin were not changed during composting periods. The contents of total and organic nitrogen were decreased but that of inorganic nitrogen was increased during composting periods. The population number of microorganism during composting periods was too much changed according to the kinds of bulking agents and microorganisms, and the composting periods.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.185-194
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• 2001

This study was designed to evaluate the effects of angulation changes of head posture on the enlargement ratios of a lateral headfilm depending on the vortical or horizontal rotation of the objects. A device was constructed to measure regional changes of enlargement ratios. The device was held within the cephalostat and cephalograms recorded at each measured degrees of the device tilting, vertically and horizontally. The enlargement ratios of the horizontal, vertical, and angular measurements on the films taken at each tilted angulations were obtained and compared with those on the films taken without rotation. In summary, the enlargement ratios of the horizontal linear measurements were decreased during horizontal rotations. The enlargement ratios of vortical measurements of the right side on the film were increased and those of the left side were decreased by the horizontal rotations. Enlargement ratios of horizontal measurements were affected further than those of vertical measurements by the same angular changes of the horizontal rotations. Therefore, a disruption of parallelism between the object's midsagittal plane and the film could result in distortion of the image while vertical rotation around the object's porionic axis would not significantly affect the enlargement ratios on the headfilm.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.16-21
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• 1998

To study the possibility of agricultural utilization of sewage sludge, the changes of the substances physico-chemical and microbiological properties composting periods such as inorganic matter, the form of organic matter and nitrogen and the kinds and the population number of microorganisms were investigated. The results were summarized as follows ; Temperature and $CO_2$ generation, they were the highest in the second day of composting periods and then were gradually fallen. pH value was not changed in first day during composting periods, but in second day was rapidly increased and then it was constant of the range of 8.4∼8.6. The contents of $P_2O,\;K_2O$, CaO and Fe were a little increased during composting periods, while that of ${SO_4}^{2-}$and Mn were big increased with 253${\sim}$331% and 191${\sim}$208% in late composting periods in comparing with early composting periods, respectively. The contents of ether extracted materials, water soluble polysaccharides, hemicellulose and cellulose were decreased but that of resins and lignin were not changed during composting periods. The contents of total and organic nitrogen during composting periods were decreased with 15${\sim}$20% and 22${\sim}$35%, respectively, while that of inorganic nitrogen was decreased with 75${\sim}$116%. The population numbers of microorganism during composting periods was much too changed according to the kinds of microorganism and composting periods.

• 발명특허
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• v.19 no.1 s.215
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• pp.18-19
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• 1994

본회가 주최한 제 119회 발명 교실이 지난 1월 8일 발명장려관 연구실에서 개최되었다. 매월 둘째 토요일 오후 1시 30분에 개최되는 발명교실은 이 달에도 1백여명이 참석하여 성황을 이루었다. 이날 발명교실에서는 코우드전자(주) 대표인 정중석 사장의 성공사례 발표와 본회 김관형 상근이사의 $\ulcorner$발명의 발상기법과 사업$\lrcorner$에 대한 강의와 토론으로 94년도 발명교실이 첫출발을 하였다. 발명가의 성공사례를 간추려 소개한다.

• 발명특허
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• v.18 no.1 s.203
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• pp.12-13
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• 1993

본회가 주최한 제 107회 발명 교실이 지난 1월 9일 발명장려관 연구실에서 개최됐다. 매월 둘째 토요일 오후 1시 30분에 개최되는 발명교실은 이 달에도 1백여 명이 참석하여 성황을 이루었다. 이날 발명교실에서는 코우드 전자 주식회사대표 정중석씨의 성공사례 발표에 이어 황종환 변리사의 $\ulcorner$산업 재산권제도$\lrcorner$에 이어 김관형 본회 상근이사의 $\ulcorner$발명의 창출과 사업$\lrcorner$에 대한 강의와 토론이 있었다. 발명가의 성공사례를 간추려 소개한다.

• 열병합발전
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• s.56
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• pp.4-8
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• 2007