• 대한치과교정학회지
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• 제19권1호
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• pp.21-44
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• 1989

Incipient changes of the periodontal tissue in the pressure zones of rat molar subjected to the experimental force were studied by the transmission electron microscope. Experimental animals were consisted in 3 control and 21 experimental rats, of which one maxillary first molar was moved buccally with a fixed appliance which were exerting the force of 15 gm. After experimental period of 1 hour, 3 hours, 6 hours, 24 hours, 2 days, 3 days and 7 days, the animal were sacrificed with cardiac perfusion of $2.5\%$ glutaraldehyde in the sodium cacodylate buffer and the experimental teeth with surrounding periodontal structures were processed for electron microscope. At the beginning of the tooth movement, periodontal ligaments of the pressure were compressed and collagenous fibers were arranged parallel to the root of the teeth and cell free zones in company with cell necrosis were followed. Cell free zones at the periodontal ligaments appeared in the 3 hour survival group, and getting severe with time lapse it became widespread in 2-3 day survival group and undermining bone resorption as a healing process was observed in 7 day survival group. Dilatation of mitochondria and swelling of the rER in the fibroblast and other connective tissue cells in the periodontal ligament were observed in the 3 hour survival group, which were characteristics of the incipient changes in the compressed periodontal ligament. Dilatation of nuclear membrane and pyknosis were followed by the destruction of the nucleus and cell membrane. There were no evidence in cell damage or necrosis of the alveolar bone adjacent to the hyalinized area of periodontal ligaments.

• 대한치과교정학회지
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• 제19권1호
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• pp.45-59
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• 1989

This study was undertaken to analyze the displacement and stress distribution in the mandible according to the pulling directions during mandibular first molar cervical traction after mandibular second molar extraction. The 3-dimensional finite element method(FEM) was used for a mathematical model composed of 594 elements and 1019 nodes. An orthodontic force, 450 gm, was applied to the each mandibular first molar in parallel, and below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$ and meet the midsagittal plane by $40^{\circ}$ toward posterior direction. The results were as follows: 1. Mandibular teeth were displaced in more downward, posterior and lateral direction. Especially high stress was noted in case of parallel pull than in case of below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$. 2. Mandibular first molar was moved bodily. 3. Generally, alveolar bone, mandibular body, ascending ramus and mandibular angle portion were displaced in downward, posterior and lateral direction. But coronoid process was displaced in downward, forward and lateral direction, and anterior and inner middle portion of condyle head and neck were displaced in downward, forward and medial direction, and posterior and outer middle portion of condyle head and neck were displaced in upward, forward and medial direction. 4. Maximum stress was observed at the condyle head and neck portion. With steeper direction of force, condyle head and neck showed more stress than parallel relation to the occlusal plane.

• Journal of Chest Surgery
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• 제25권4호
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• pp.391-397
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• 1992

Postoperative hypoxemia in the absence of hypoventilation occurs more often after thoracic or upper abdominal surgery than lower abdominal operations or surgery on extremities. Although the factors which produce postoperative alveolar collapse have not been fully evaluated, the dominant factor of postoperative hypoxia is shunt of blood passing collapsed alveoli and the postoperative pain is associated with restriction of depth of breathing, sighing and movement. In 1979, the first successful clinical usage of epidurally administered morphine was done by Behar and associates for control of postoperative pain. This study was carried out for twenty patients who received posterolateral thoracostomy with Bled resection between May 1990 and May 1991 and who were primary spontaneous recurrent pneumothoraxes. We selected ten of twenty patients, one after the other and treated with epidural analgesia as study group and the remainder ten were grouped as control. Epidural catheters were inserted for study group before operation through T12-L1, 2 interspinous process at the pain clinic or operation room by anesthesiogist and then the drugs[0.25% Bupivacaine 15ml mixing with morphine 3mg] were instillated through the catheter before extubarion and once a day until 4th day, and the patients of control group were treated intermittently by Demerol 50mg intramuscularly for postoperative pain control. The epidural catheters were removed at postoperative 4th day. Observations were done about vital aigns, a-BGA, tidal volume, FVC and occurence of adverse effects during postoperative 2hr, 8hr, 1st day, 2nd day, 7th day in both groups. The results were as follows; [1] Tidal volume[85.1$\pm$29.8%R VS 60.8$\pm$20.5%R, p<0.05] and FVC[53.7$\pm$14.2%R, VS 35.5$\pm$9.l%R, p<0.01] were significantly improved in study group compared with control group during the first day of operation. [2] But the improvement of FVC was delayed after stopping of epidural analgesia[postoperative 7th day, 97.5$\pm$12.3%R VS 83.9$\pm$15.6%R, P <0.05]. [3] Others were statistically not significant. [4] The side effects of epidural analgesia were identified such as urinary retention[2 cases], itching sensation[1 case] and headache[1 case], but there was no need for active treatments.

• 치과방사선
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• 제24권1호
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• pp.95-105
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• 1994

The aim of this study was to evaluate the clinical, radiographic and histopathologic features of 23 cases of solitary bone cyst by means of the analysis of radiographs and biopsy specimens in 23 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chunbuk National University. The obtained results were as follows; 1. The incidence of solitary bone cyst was almost equal in males(52.2%) and in females(47.8%) and the prevalent age of the solitary bone cyst were the second decade(47.8%) and the third decade (21.7%). 2. In the signs and symptoms of solitary bone cyst, pain or tenderness revealed in 17.4%, swelling revealed in 13.0%, pain and swelling revealed in 21.7%, paresthesia revealed in 4.4% and 43.5% were asymptom and the tooth vitality involved in the solitary bone cyst, 76.5% were positive and 23.5% were either positive or negative. 3. In the location of the solitary bone cyst, 47.8% present posterior region, 21.7% present anterior region, 21.6% present anterior and posterior region, 4.4% present condylar process area. 4. In the hyperostotic border of the solitary bone cyst, 47.8% were seen entirely, 21.8% were seen partialy, and 30.4% were not seen. 5. In the change of tooth, 59.1% were intact, 18.2% were loss of the alveolar lamina dura, 13.6% were root resorption 4.55% were tooth displacement, 4.55% were root resorption and tooth displacement. 6. In the change of cortical bone of the solitary bone cyst, 39.1% were intact and 60.9% were thinning and expansion of cortical bone. 7. In the histopathologic findings of 9 cases, 33.3% were thin connective tissue wall, 11.1% were thickened myxofibromatous wall, 55.6% were thickened myxofibromatous wall with dysplastic bone formation.

• 한국어류학회지
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• 제24권4호
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• pp.247-252
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• 2012

한국산 송사리속 2종에 대한 섭이기관의 구조적 차이를 알아보기 위하여 악골 및 이빨 구조를 조사하였다. 악골에서 송사리 Oryzias latipes는 전상악골 중앙부의 등 쪽 가장자리에 움푹 들어가는 홈이 존재하였으나 대륙송사리 O. sinensis는 일직선이었다. 후반부의 위치에서 송사리는 중앙부와 일직선상에 존재하였으나 대륙송사리는 배 쪽에 존재하였다. 또한 송사리는 하악골의 구상돌기 아래로 이어지는 치골 뒷가장자리에 움푹 들어가는 홈이 존재한 반면에 대륙 송사리에서는 뒷가장자리가 일직선 모양을 하였다. 송사리는 성적이형으로서 수컷에서만 나타나는 큰 이빨이 하악골의 측면 방향으로 발달하였고, 대륙송사리는 등 쪽 방향으로 발달하였다. 한편 송사리의 이빨형태는 원뿔모양과 화살촉모양 2 types이 나타난 반면에 대륙송사리에서는 원뿔 모양 1 type만 나타나는 특징을 보였다. 이상과 같이 한국에 분포하는 2종의 송사리는 섭이기관에서 뚜렷한 종간의 특징을 잘 보여 주었다.

• 대한치과교정학회지
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• 제43권5호
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• pp.225-234
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• 2013

Objective: The purpose of this study was to classify Korean young adults into 3 groups on the basis of upper incisor exposure rates (UIERs) and to compare the skeletal, dental, and soft tissue variables. Methods: Samples were obtained from 127 students at the College of Dentistry, Wonkwang University in South Korea. Facial photographs of frontal posed smiles and lateral cephalograms of the subjects were taken. The subjects were divided into 3 groups on the basis of UIERs and 20 measurements were compared among the 3 groups. The correlations between the variables were determined. Results: Male and female subjects showed significant differences in the group distribution. Male subjects showed higher frequencies of low smiles, and female subjects showed higher frequencies of high smiles. The vertical height of the anterior alveolar process of the maxilla directly correlated with the UIER. However, the UIER showed no significant correlation with the vertical height of the anterior basal bone or the inclination of the upper incisor axis. In female subjects, the upper central incisor clinical crown length showed an inverse correlation with the UIER. However, this variable showed no significant correlation with the UIER in male subjects. Conclusions: The UIER was directly correlated with the levator muscle activity of the upper lip and inversely correlated with the upper lip thickness, yet there was no correlation between the UIER and upper lip length at rest.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.438-457
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• 1995

The origin of fibroblasts, their proliferative activity and roles in the early stages of periodontal regeneration were investigated in order to better understand the periodontal healing process in furcation defects of the beagle dog after guided tissue regeneration. Newly divided cells were identified and quantitated by immunolocalization of bromodeoxyuridine (BrdU) injected 1 hour prior to sacrificing the animals. The results were as follows :1. During periodontal healing in horizontal furcation defect, three different stages, namely the granulation tissue, connective tissue, and bone formation stages, were identified on the basis of major types of cells and tissue. 2. In the early stages of periodontal regeneration, both the remaining periodontal ligament and alveolar bone compartment were the major sources. 3. The majority of BrdU-labeled fibroblasts were located at the following areas ; 1) the coronal zone of the defect in case of the connective tissue fanned on the root surface. 2) the area within an 400 ${\mu}m$ distance from the remaining bone level in case of the periodontal ligament. 3) the area within an 100 ${\mu}m$ distance from the bone surface in case of areas of active bone formation.4. The highly proliferative fibroblasts adjacent to bone surface played a major role in the formation of osteoblast precursor cells, whereas both paravascular and endosteal cells played a minor role in new bone formation, In conclusion, it was suggested that the fibroblasts in the remaining periodontal ligament and bone will play a major role in periodontal regeneration, whereas both paravascular and endosteal cells will play a minor role in new bone formation.

• Journal of Periodontal and Implant Science
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• 제25권3호
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• pp.623-634
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• 1995

Periodontitis is characterized by gingival inflammation and results in periodontal pocket formation with loss of the supporting alveolar bone and connective tissue around the teeth. Therapeutic modalities should therefore aim not only at eliminating the gingival inflammatory process and preventing the progression of periodontal disease but also at reestablishing and regenerating the periodontal tissue previously lost to the disease. To achieve periodontal regeneration, progenitor cells must migrate to the denuded root surface, attach to it, proliferate and mature into an organized and functional fibrous attachment apparatus. Likewise, progenitor bone cells must also migrate, proliferate, and mature in conjunction with the regenerating periodontal ligament. Significant advances have been made during the last decade in understanding the factors controlling the migration, attachment and proliferation of cells. A group of naturally occuring molecules known as polypeptide growth factors in conjunction with certain matrix proteins are key regulators of these biological events. Of these, the fibroblast growth factor(FGF), platelet-derived growth factor(PDGF) , insulin like growth factor(CIGFs), transforming growth factor(TGFs), epidermal growth factor(EGF) and bone morphogenetic growth factor(BMPs) apper to have an important role in periodontal wound healing. The purpose of this study was to determine the effects of BMP on periodontal ligament cells. Human periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Cultured periodontal ligament cells were treated with BMP. Cellular activities were determined by MTT(3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay and ALP(alkaline phosphatase) activity. The results were as follows ; Regardless of cultured time, cellular activities were stimulated by BMP. Also, BMP greatly increased alkaline phosphatase(ALP) in periodontal ligament cells. These results suggest that BMP not only have no cytotoxic effect on periodontal ligament cells, but also have osteogenic stimulatory effect on periodontal ligament cells.

• 대한임상독성학회지
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• 제3권1호
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• pp.40-44
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• 2005

Nitrogen dioxide ($NO_2$), which produced during the process of silage, metal etching, explosives, rocket fuels, welding, and by-product of burning of fossil fuels, is one of major components of air pollutant. Accidental exposure of high level of $NO_2$ produces cough, dyspnea, pulmonary edema which may be delayed $4\~12$ hours and, in $2\~6$weeks, bronchiolitis obliterans. We experienced a case of acute pulmonary injuny induced by industrial exposure to high level of $NO_2$ during repair of $NO_2$ pipeline in a refinery. A 55-year-old man experienced nausea and severe dyspnea in 6 hours after $NO_2$ inhalation. Initial blood gas examination revealed severe hypoxemia accompanying increased alveolar-arterial O2 difference. Radiological examination showed diffuse ground glass opacities in both lung fields. Clinical symptoms and laboratory findings, including radiological study and pulmonary function test were improved with conservative treatment using inhaled oxygen and bronchodilator. and there was no evidence of bronchial fibrosis and bronchiolitis obliterance in chest high resolution computed tomography performed 6 weeks after exposure. Here, we report a case of $NO_2$ induced acute pulmonary injuny with a brief review of the relevant literature.

• 구강회복응용과학지
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• 제25권4호
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• pp.431-436
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• 2009

심한 치조골 흡수를 동반한 III급 악골 관계 환자의 총의치 제작의 경우 안정적이고 지속적인 교합을 제공하는 치료계획을 세워야 한다. 불리한 치관 대 치근 비와 임상적 동요도가 관찰되는 하악 잔존치를 고정하여 사용함으로써 환자의 불편감을 줄이고 시간적, 경제적으로 효율적인 치료를 제공할 수 있다. 본 증례에서는 상악 편악 무치악 환자의 기능적인 하악 운동과 조화로운 총의치 균형 교합을 이루기 위해 T-Scan System을 이용하였다.