• 대한치과교정학회지
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• 제20권3호
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• pp.447-462
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• 1990

The objective of this experiment is to observe structural differences in the othodontic movement of vital (control group) and devitalized (experimental group) teeth in the mongrel dogs. The 5 utilized dogs in this experiment were approximately 1 year of age and their average weight was about 12 Kg. Endodontic therapy was performed on the 2nd premolars in upper & lower jaws of each animal under the general anesthesia by intravascular injection of 25mg/kg of pentobarbital sodium. The canals of the teeth were obturated by using gutta percha in conjunction with root canal sealer (AH26 Densply). One of the roots in the 2nd premolars was hemisected to make an extraction space for the devitalized teeth to be moved. The edgewise technique was employed for the movement of the teeth. Orthodontic models and intraoral roentgenograms were taken before and after orthodontic tooth movement. The open coil springs (.010 x .040) were used at interbraket space in order to provide equal forces (75gm) between the teeth in each arch wire. After 13 weeks of active orthodontic tooth movement, dogs were sacrified and the experimental results w ere examined through the intraoral radiography, microscopic examination and scanning electromicroscopic examination at the root sulfate. From the results of the study, the following conclusions may be drawn: The root resolution and cemental deposition were observed within the pressure and tension site in both group. 2. The root resorbed lacunae were observed in the cementum and/or into the dentin in both group. 3. The prominent osteoblastic activities were observed on the alveolar margin in the tension site in both group. 4. A few of blood vessels were observed in the pressure site, but also lots of blood vessels were observed in the tension site especially in the periphery of the alveolar bone in both group. 5. In the pressure site, resorbed lacunae were formed with deep and narrow cavity in the control group; the shallow and wide cavity in the experimental group. 6. In the pressure site, the repaired cementum or cementoid tissue was lined on cementum in the experimental group, but not in the control group. 7. There was no significant difference between external root resolution of endodontically and vital teeth when both were subjected to orthodontic forces.

• 한국임상수의학회지
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• 제24권1호
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• pp.62-67
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• 2007

Two cases of vital pulpotomy for treatment of open fractured canine teeth in dog were referred to the Veterinary Teaching Hospital of College of Veterinary Medicine, Chonnam National University. In case 1, a 2-year-old male Locker. Spaniel was fractured left mandibular canine and the pulp was exposed. In case 2, an 1-year-old male Border Collie was open fractured both mandibular canine teeth. In both cases, we made sure of pulp vitality by oral examination and radiological findings. Therefore, we performed vital pulpotomy in these patients. Two months after therapy, radiological examinations were performed for evaluation of success of therapy. In both cases the radiographs showed normal periapical anatomy and no changes in the root resorption.

• 대한치과교정학회지
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• 제48권5호
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• pp.283-291
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• 2018

Objective: This study was conducted to perform histomorphometric evaluations of the bone surrounding orthodontic miniscrews according to their proximity to the adjacent tooth roots in the posterior mandible of beagle dogs. Methods: Four male beagle dogs were used for this study. Six orthodontic miniscrews were placed in the interradicular spaces in the posterior mandible of each dog (n = 24). The implanted miniscrews were classified into no loading, immediate loading, and delayed loading groups according to the loading time. At 6 weeks after screw placement, the animals were sacrificed, and tissue blocks including the miniscrews were harvested for histological examinations. After analysis of the histological sections, the miniscrews were categorized into three additional groups according to the root proximity: high root proximity, low root proximity, and safe distance groups. Differences in the bone-implant contact (BIC, %) among the root proximity groups and loading time groups were determined using statistical analyses. Results: No BIC was observed within the bundle bone invaded by the miniscrew threads. Narrowing of the periodontal ligament space was observed in cases where the miniscrew threads touched the bundle bone. BIC (%) was significantly lower in the high root proximity group than in the low root proximity and safe distance groups. However, BIC (%) showed no significant differences among the loading time groups. Conclusions: Regardless of the loading time, the stability of an orthodontic miniscrew is decreased if it is in contact with the bundle bone as well as the adjacent tooth root.

• 대한소아치과학회지
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• 제23권2호
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• pp.525-536
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• 1996

The purpose of this study was to investigate the effect of electrical anesthesia induced by non-acupuncture point stimulation on inhibition of amplitude of digastric EMG evoked by noxious electrical stimuli in teeth and gingiva. Experiments were performed with dogs anesthetized with intraperitoneal pentobarbital sodium in an initial dose of 30mg/kg. Maintenance doses of 4.0ml/hour were given through a cannula in the femoral vein using a constant infusion pump. Anterior belly of digastric muscle was exposed and a pair of 0.1mm wire electrodes were inserted for E.M.G. recording. Bipolar electrodes were inserted into the labial and lingual surface of upper canine and the labial area of upper gingiva. Noxious stimuli were delivered to the tooth and gingiva through those electrodes by electric stimulator. Non-acupuncture point stimulation of 2Hz was delivered bilaterally to the femoral area. Amplitudes of digastric E.M.G. were measured from the oscilloscope and the monitor connected to amplifier at different intensities of electronic anesthesia of 1 volt, 4 volt and 10 volt. The inhibited rate of the amplitudes of digastric E.M.G. were analysed statistically with paired t-test. The following results were obtained : 1. Non-acupuncture point stimulation with intensities of 1 volt, 4 volt and 10 volt showed the inhibitory effect on pain of 15%, 25% and 16% in teeth and 15%, 18% and 12% in gingiva respectively 2. In tooth, statistical significance was observed between control and each group. In gingiva, there was statistical significance between control and group 1, 2 except group 3 From these results, low frequency electrical stimulation of non-acupuncture point resulted in reducing of dental and gingival pain, it could be used as adjunct to other pain control methods.

• 대한치과교정학회지
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• 제26권4호
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• pp.359-371
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• 1996

교정력에 의한 성견의 치아이동시 발생하는 조직변화 중 치주인대 내에서의 세포활성도의 변화를 교정력의 크기와 기간에 따라 알아 보고자 하였다. 생후 1년 6개월된 성견 6마리를 5마리의 실험군과 1마리의 대조군으로 나누었고 실험군에서 하악 좌측에는 강한 힘 (250-300g)을, 하악 우측에는 약한 힘 (50-75g)을 제1소구치와 제2소구치 사이에 open coil spring으로써 적용하였다. 실험군의 성견을 각각 12시간, 24시간, 3일, 1주, 2주에 Bromodeoxyuridine(BrdU)을 주입하고 희생시켰다. 하악 제 1,2 소구치 부위의 조직을 채득하여 통법에 따라 파라핀 포매하였으며, H & E 염색과 항 BrdU 항체를 이용한 면역조직화학적 염색을 시행한 결과 다음과 같은 결론을 얻었다. 견인측에서의 치주인대 단절과 혈관확장은 12시간째에서 관찰되어 증가하다가 3일째 이후에는 감소되었는데 약한 힘을 준 경우보다 강한 힘을 준 경우에서 더 많았으며 압박측에서의 치주인대의 초자양변성과 파골세포 활성은 12시간째에서부터 관찰되어 3일째까지 증가하다가 7일째부터 감소하였는데 약한 힘을 준 경우보다 강한 힘을 준 경우에서 더 많이 나타났다. 대조군의 BrdU 발현은 구강상피와 치주인대의 섬유모세포에서 주로 많았고 골세포나 파골세포에서는 음성 반응을 보였으며 실험군의 BrdU 발현은 압박 측보다 견인측에서 많았으며 치경부쪽보다는 치근단쪽에서 더 많았다. 약한 힘을 준 경우에서는 BrdU 발현이 1일째에 가장 많이 나타나다가 감소되었고 강한 힘을 준 경우에서는 12시간째에서 최고에 달하다가 이후에는 감소되었으나 14일째에는 실험군과 대조군 간에 큰 차이가 없었다.

• 대한치과교정학회지
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• 제34권2호
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• pp.131-142
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• 2004

본 연구는 골절단을 이용한 치아-치조골 분절의 급속 치아이동 후 치수, 치주인대 및 치조골의 변화를 유성견에서 평가하고자 하였다. 하악 제4소구치의 근심, 원심, 치근단 부위에서 피질골을 절단하여 치아-골 분절을 형성하고 하악 제3소구치를 발거하면서 협측, 설측 부위의 피질골을 삭제하였다. 1주 휴지기 부여에 따라 휴지기군과 비휴지기군으로 나누어 치아의존형 견인장치로 6일 동안 견인하고 강화기를 거친 후 0주, 1주, 2주, 4주, 6주, 8주에 희생시켜 치수 치주인대 및 치조골의 조직 변화를 임상적, 방사선적, 조직학적 및 면역화학적으로 평가하여 다음과 같은 결과를 얻었다. 1 치아이동 양과 강화기 동안의 조직 치유 양상에서 휴지기 유무에 따른 차이는 없었다. 2. 견인측에서 골형성은 강화기 8주까지 계속되었는데 강화기 1-2주에 가장 활발하였으며 6-8주간의 변화는 적었다. 3. 비휴지기군의 강화기 1주에서 치조골 흡수 및 파골세포 출현, 염증세포 침윤이 가장 많았으며, 특징적으로 파상아세포가 압박측의 치주인대와 치수 내에 나타났다. 4. $TGF-\beta$는 치조골의 골기질 및 골모세포, 파골세포, 치수 내 파상아세포에서 강양성 발현을 보인 반면 치수, 백악모세포, 무세포성 백악질에서 경미한 양성 발현을 나타내는 부위 특이성이 있었다. 5. $TGF-\beta$는 견인측 치주인대의 치조골에 인접한 혈관 및 치주인대세포, 골모세포에서 강화기 초기 1-2주에 주로 발현되었으며 6주 이후에는 발현이 크게 감소하였다.

• 대한치과교정학회지
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• 제21권2호
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• pp.259-272
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• 1991

Orthodontic traction has been suggested as the treatment of choice for intrusive luxation injuries. Prior research has shown orthodontic forces to be ineffective in the presence of ankylosis or in cases with zero mobility following the injury. If orthodontic traction is to be effective, it must be initiated prior to the onset of ankylosis. The purpose of this study was to describe the effects of intrusive luxation at various times following the injury, and to determine the time of the onset of ankylosis, and to examine what effect immediate partial luxation has on the onset of ankylosis. Eight young mongrel dogs were utilized for this study. Intrusive luxation was produced with an axial impact using a gravity hammer and a specially designed holding device on 4 teeth (2 max. and 2 man. first premolars) in each dog. The teeth were intruded approximately 3-4mm in an axial direction. One maxillary and one mandibular premolars were partially luxated with the other two teeth being untouched. Pre and posttrauma tooth position was documented with plaster models and radiographs taken with an individualized X-ray jig. Dogs were sacrificed immediately following the injury and at 1, 2, 4, 7, 10, 14 and 21 days respectively. Tetracycline was administered as a vital bone marker 24 hours before sacrifice. Block sections of the tooth and alveolus were prepared for decalcified and non decalcified histologic sections. The effects of traumatic intrusion were analyzed by means of model casts, radiographs, tetracycline bone marking and histologic preparations. The results obtained were as follows: 1. The animal sacrificed immediately following the injury displayed alveolar fractures, torn periodontal ligaments, and areas of direct tooth-bone contact. 2. The odontoblastic layer of the pulp was disorganized as early as 24 hours after the injury. 3. Bony remodeling was noted at 4 days along with active surface resorption. 4. Ankylosis was first seen 7 days after the injury. 5. Osteogenesis in the dentin (thick tetracycline bands) was observed 7 days after the injury. 6. There was no progressive root resorption and ankylosis where the periodontal ligament has been healed. 7. The Luxated group showed significantly more root resolution and ankylosis than the Nonluxated group with increased observation periods. The results suggest that ankylosis may occur within the first week following the injury, and hence orthodontic traction should be initiated as soon after the injury as possible.

• 한국임상수의학회지
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• 제26권1호
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• pp.41-47
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• 2009

Ingredient analysis and the medical action of various teas are accomplished on multi angle. However, the research regarding the prevention and a treatment of oral cavity disease, which use the green tea, is still insufficient relatively. In this experiment, the virtue of green tea bag on periodontal disease was studied. This experiment was used in 11 beagles. As a test group, 6 beagles were rinsed their tooth with green tea bag. The remaining 5 beagles were rinsed with filter paper which was soaked with normal saline. The test found no statistical significance in gingival index, plaque index, calculus index and dental pocket depth. But the number of bacteria colonies decreased significantly in test groups. The periodontal disease is related to the number of bacterial colonies. Therefore, this results show that the green tea bag is effective for periodontal disease.

• Journal of Periodontal and Implant Science
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• 제46권5호
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• pp.291-302
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• 2016

Purpose: The aim of the present study was to evaluate the effectiveness of using a mineralized bone cortical allograft (MBCA), with or without a resorbable collagenous membrane derived from bovine pericardium, on alveolar bone remodeling after immediate implant placement in a dog model. Methods: Six mongrel dogs were included. The test and control sites were randomly selected. Four biradicular premolars were extracted from the mandible. In control sites, implants without an allograft or membrane were placed immediately in the fresh extraction sockets. In the test sites, an MBCA was placed to fill the gap between the bone socket wall and implant, with or without a resorbable collagenous membrane. Specimens were collected after 1 and 3 months. The amount of residual particles and new bone quality were evaluated by histomorphometry. Results: Few residual graft particles were observed to be closely embedded in the new bone without any contact with the implant surface. The allograft combined with a resorbable collagen membrane limited the resorption of the buccal wall in height and width. The histological quality of the new bone was equivalent to that of the original bone. The MBCA improved the quality of new bone formation, with few residual particles observed at 3 months. Conclusions: The preliminary results of this animal study indicate a real benefit in obtaining new bone as well as in enhancing osseointegration due to the high resorbability of cortical allograft particles, in comparison to the results of xenografts or other biomaterials (mineralized or demineralized cancellous allografts) that have been presented in the literature. Furthermore, the use of an MBCA combined with a collagen membrane in extraction and immediate implant placement limited the extent of post-extraction resorption.

• 대한치과교정학회지
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• 제30권3호
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• pp.317-333
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• 2000

급속 구개확장은 정중구개봉합을 이개하기 위하여 강한 힘을 치아에 가하게 된다. 확장후 정중구개봉합부에 존재하는 골모세포와 섬유모세포의 증식 활성도를 측정하여 정중구개확장이 생리적으로 진행되는지를 확인하고, 이때 개개 치아의 치주조직에서 나타나는 변화를 조사하기 위하여 약 10개월된 유성견 10마리를 대상으로 상악 제2소구치와 제1대구치에 Hyrak screw를 장착하였다. 실험동물은 대조군 1마리, 1주 확장한 군 3마리, 2주 확장한 군 3마리, 2주 확장후 2주 보정한 군 3마리로 구분하여, Screw를 1일 1/4회전시켜 확장하였고, 제2소구치, 제3소구치, 그리고 제 1대구치 부위의 정중구개봉합부와 치주조직을 절취하여 Soft X-ray로 관찰하고, 형태학적 및 면역조직화학적 변화를 광학현미경으로, 그리고 골개조를 편광현미경으로 관찰하여 다음과 같은 결과를 얻었다. 1. 편광현미경 소견에서는 대조군에 비하여 1주 확장군의 봉합부에서 골 형성과 흡수가 크게 증가되었으며, 2주 확장군에서 약간 감소를 보이다가, 보정군에서는 석회화가 크게 진행되었다. 2. 면역조직화학적 연구에서는 대조군에 비하여 1주 확장군의 봉합부에서 골모세포가 PCNA(Proliferating Cell Nuclear Antigen)에, 미분화 섬유모세포가 EGF(Epidermal Growth Factor)에 약간 증가된 양성 반응을 보였으며 EGF에 대한 골모세포의 반응은 낮았다. 2주 확장군에서는 섬유아세포와 골모세포에서 PCNA와 EGF에 대한 양성반응이 증가되었다. 보정군에서는 이들 PCNA와 EGF에 양성반응을 나타내는 세포들이 구개돌기 골단 주변에 집중되었다. 3. 확장기간 중 봉합부 주변에서 광범위한 골 흡수와 골형성을 동반한 골개조가 일어났으며, 보정군에서는 다소 감소하였다. 2주 확장군과 보정군의 제3소구치 와 제1대구치의 치근단에서 백악질 형성과 흡수가 나타났으며, 제1대구치의 협측 치경부에서 광범위한 초자양 변성대가 나타났다. 4. Soft X-ray소견에서 1주 확장군은 대조군에 비교하여 봉합부위의 여러부분에서 미세 파절과 저석회화된 결손부위를 보였다. 대조군과 보정군 사이 에는 정중구개봉합부의 석회화 정도에 별 차이 가 없었다. 2주 확장군과 보정군에서 제3소구치와 제1대구치는 협측으로 경사되는 경향을 보였다.