• 대한치과교정학회지
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• 제11권2호
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• pp.65-70
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• 1981

In the present study orthodontic force was applied to the molars of control group and experimental group treated with the lathyrogen beta-aminopropionitrile (BAPN). Observation resulted in the following conclusions : 1) New alveolar bone formation in response to orthodontic force in BAPN-treated rats exceeded corresponding bone formation in control of cup when measured at two tension sites in the periodontal ligament. 2) BAPN administration produced disorganization of the collagenous fibers of the periodontium of experimental group. Multiple eosinophilic cell-free areas were found distributed throughout the radicular portions of affected periodontal ligaments. 3) The areas of periodontium surrounding orthodontically treated teeth exhibited relatively normal organization under these conditions, while the periodontium of adjacent nonorthodontically treated teeth was disorganized. 4) The present results suggest that the typical histologic response to orthodontic force application can occur in the presence of a chemically and physically altered periodontium.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.117-130
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• 1999

All contours of the restoration not directly related to occlusion are related to the gingival tissues only.And proper contour of restoration is essential for the health of the periodontal tissues.But there are so many controversies about the contour of the restoration, and there is no uniform agreement in the literature as to which contour of restoration is best for periodontium. In general, the contour of restoration means the supragingival contour only but in the case of the intracrevicular restorative procedure the subgingival contour of restoration must be considered. Because a portion of the restoration is placed in a gingival sulcus which is extremely vulnerable to periodontal disease. In this article the concepts or theories of the supragingival contour, the subgingival contour, and the emergence profile were discussed.The contour of the restoration and the biotype of the periodontium must be considered in intracrevicular restorative procedure.And sufficient tooth preparation is important factor to develop the proper contour of restoration which is kind to periodontium.

• 대한치과보철학회지
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• 제38권3호
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• pp.283-290
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• 2000

State ment of Problems. Although some clinicians report long-term success with fixed partial denture (FPD) that contain cantilever pontic, the use of cantilever FPDs may be hazardous because of unfavorable leverages during mastication. Purpose of Study. This study aims to compare the stress induced in the periodontium with normal and reduced bone support, and to analyze the stress distribution patterns of anterior cantilevered FPDs using the finite element method. Results. Cantilever bridge with a reduced bone level generated the highest peak stresses in the periodontium. In the models of reduced bone support, a cantilever bridge exhibited the great-est mobility and a 3-unit fixed restorations induced the smallest mobility of canine. The highest peak stress level of a 3-unit bridge in the periodontium is similar to the unrestored situation. But stress distribution in the bone is modified. Conclusion. In reduced bone support, a cantilever bridge exhibited the greatest mobility and stress.

• 대한치과보철학회지
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• 제9권1호
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• pp.47-51
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• 1969

The author has studied the histochemical changes on rat submaxillary gland histological changes on rat periodontium after administration of isoproterenol. The results are as follows: 1) After administration of isoproterenol, the rat submaxillary glands weight of the first and second group were increased two times compared with control group. 2) The acinar cells of rat submaxillary gland were shown the hypertrophy and enlargement. 3) The PAS staining reaction of the acinar cells of rat submaxillary gland were shown the strong positive reaction. 4) The blood vessels of rat periodontium were dilated and alveolar bone resorption was occurred.

• 대한치과교정학회지
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• 제23권1호
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• pp.89-100
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• 1993

The purpose of this study was to evaluate the effect of orthodontic force on periodontal cellular activity by immunoperoxidase stain of epidermal growth factor, one of the tissue hormone. And supplementarily, to investigate of the changes of periodontal structures, periodontium was stained by H-E, Masson's Trichrome, P. A. S. stain after orthodontic force application. The experimental animals were four young adult dogs of average 8 month old. The fixed orthodontic appliance was cemented on mandibular right 4th premolar and 1st molar of each animal as experimental site. Mandibular left 4th premolar area of the same animal was used as control. The appliance consist of two silver crown soldered with 0.030' tube, $0.018\times0.022'$ S.S. sectional arch wire, and 0.009' open coil spring for manifestating of orthodontic force for bodily tooth movement of mandibular 4th premolar toward mesial direction. Experimental group was sacrificed at 1, 2, 3, 5 weeks from beginning of the experiment, and was investigated immunohistochemically and bistochemically by several staining methods. Findings were as follows: 1. The degree of EGF staining in control group was highest in epithelium of periodontium, and osteoclasts, osteoblasts and fibroblasts around the capillary were stained at higher level in periodontium. Generally, control group shows positive distribution of EGF all around the periodontal area. 2. The degree of EGF staining in control and 5 week group were similar, and did not show the significant different level between tension and pressure side. 3. All of 1, 2, 3 week group showed the same staining degree and distribution of EGF, and the tension side was more positive reaction of EGF stain than the pressure side. 4. The features of collagen fiber and periodontal fiber arrangement observed by H-E, Masson's Trichrome and P. A. S. stain revealed that oblique periodontal fibers were strectched in tension side, compressed in pressure side of all experimental group. Some fiber group in pressure side of 5 week group recovered the regular arrangement along the capillaries.

• 대한소아치과학회지
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• 제45권2호
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• pp.144-153
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• 2018

본 연구는 치근 및 치주조직의 형성과정동안 Sonic Hedgehog (SHH) signaling의 역할에 대해 알아보고자 치성간엽에서 조직특이적으로 Smoothened (Smo)가 활성화 또는 차단되는 mouse를 제작하여 분석하였다. 생후 28일경 Smo 활성화모델에서는 H-E 염색 시 얇은 두께의 치근상아질, 넓어진 치수강, 치주인대공간에 느슨하게 배열되어있는 섬유들이 관찰되었다. 면역조직화학염색 시 Smo 활성화모델은 wild type mouse와 비교하여 백악질, 치주인대 그리고/또는 백악모세포의 표식자인 Bsp, Dmp1, Periostin, Ank 같은 기질 단백질들의 발현이 현저히 감소하였다. 그러나 Smo 차단모델은 wild type mouse와 비교하여 이러한 기질 단백질들의 발현에 차이가 보이지 않았다. 본 연구를 통하여 치근 및 치주조직의 정상적인 형성과정에 낮은 수준으로 조절되는 SHH signaling이 필요하다는 것을 확인할 수 있었다.

• Molecules and Cells
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• 제37권7호
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• pp.562-567
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• 2014

Human Hertwig's epithelial root sheath/epithelial rests of Malassez (HERS/ERM) cells are epithelial remnants of teeth residing in the periodontium. Although the functional roles of HERS/ERM cells have yet to be elucidated, they are a unique epithelial cell population in adult teeth and are reported to have stem cell characteristics. Therefore, HERS/ERM cells might play a role as an epithelial component for the repair or regeneration of dental hard tissues; however, they are very rare population in periodontium and the primary isolation of them is considered to be difficult. To overcome these problems, we immortalized primary HERS/ERM cells isolated from human periodontium using SV40 large T antigen (SV40 LT) and performed a characterization of the immortalized cell line. Primary HERS/ERM cells could not be maintained for more than 6 passages; however, immortalized HERS/ERM cells were maintained for more than 20 passages. There were no differences in the morphological and immunophenotypic characteristics of HERS/ERM cells and immortalized HERS/ERM cells. The expression of epithelial stem cell and embryonic stem cell markers was maintained in immortalized HERS/ERM cells. Moreover, immortalized HERS/ERM cells could acquire mesenchymal phenotypes through the epithelial-mesenchymal transition via TGF-${\beta}1$. In conclusion, we established an immortalized human HERS/ERM cell line with SV40 LT and expect this cell line to contribute to the understanding of the functional roles of HERS/ERM cells and the tissue engineering of teeth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권2호
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• pp.125-130
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• 2009

For many years, intermaxillary fixation using arch bar has been operated in treatment of mandibular fracture patients. But it has many complications including injury of operators and assistants cause by wire, inflammation of periodontium. For that reasons alternatives are required; osteosynthesis technique using mini plate, intermaxillary fixation using IMF screws have been available. Treatment by arch bar fixation, however, is still valuable to treat craniomaxillary fracture patients. The purpose of this study is to know effect arch bar on periodontium and influence gingival gel on periodontium applied by arch bar. 40 mandibular fracture patients are monitored. 30 patients were applied by arch bar, 10 patients were not. And the former were classified by 3 categories; Nano vitamin and Mastic gel were applied to 10 patients respectively and any gingival gel was not used to 10 patients. Clinical attachment level, bleeding on probing and periodontal depth of each group were measured and compared before operation and on 2 weeks and 6 weeks after operation. Mann-Whitney U test was used to analyze result which leads to this conclusion. 1. Whether arch bar is applied or not, treatment of mandlbular fracture gave rise to gingivitis, but 6 weeks after operation, gingivitis is restored to the same level as the state before operation. 2. More severe gingivitis appeared when arch bar is applied to mandibular fracture than when it is not. 3. Both gingival gel used in this study can reduce gingivitis which can be caused by arch bar. 4. In this study, Mastic gel is more effective for prevent gingival inflammation cause by arch bar than nano vitamin. In regard to this result, gingivitis is considered to be available because it is reversible and does not induce periodontal disease. Gingival gel is regarded to be helpful for patients applied by arch bar to feel less discomfort.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.499-508
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• 2004

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, autogenous bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of autogenous bone and xenogenic bone $(BBP^{(R)})$ grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, autogenous bone with PRP was inserted for 25 infrabony pockets as first test group, and $(BBP^{(R)})$ with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. There were significant differences between average probing pocket depth and clinical attachment level of 3, 6 months and minimal and maximal attachment level after 6 months each other. 2. There were significant differences in average probing pocket depth of control group and 2nd experimental group between 1 and 6 months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6 month of surgery. 3. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minimal and maximal probing attachment level. As the result, PRP with bone graft could be very effective for regeneration of periodontium and there was no difference between xenogenic bone and autogenous bone.

• 대한치과교정학회지
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• 제18권2호
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• pp.435-447
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• 1988

This study was performed to evaluate the effect of low-power laser irradiation on the periodontium of the orthodontically moved tooth of rat. The experimental materials were 30 male rats. Orthodontic appliances were placed bilaterally between maxillary first molar and incisor teeth and the force was 1 Oz. Experimental animals were divided into eight groups as follows: no movement, 1st, 2nd, 3rd, 5th, 7th, 14th, and 28th day groups. In all experimental animals except no movement group, low-power laser was irradiated on the unilateral maxillary first molar (experimental side), but on the contralateral side, only orthodontic force was applied (control side). The histologic effects of laser on the periodontium of the orthodontically moved tooth on the consecutive experimental days were as follows: In the experimental side, by the biostimulating effect of laser, 1. Hyalinized tissue was formed later and eliminated earlier than in the control side. 2. Undermining bone resorption was occurred earlier than in the control side. 3. More osteoid tissue was deposited and calcified earlier than in the control side. 4. The most prominent changes were formation of new blood vessels and dilatation of old blood vessels.