• 대한치과의사협회지
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• 제50권4호
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• pp.196-202
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• 2012

Radiographic diagnosis of periapical lesions is based on many factors, including anatomical limitations such as thickness of the cortical bone; positioning of the apical abscess to the cortical bone; and is complicated by proximity to other anatomical structures and neighboring teeth. With conventional radiographs, these structures are often superimposed. Dental CBCT with its associated geometric accuracy offers accurate visualizations of the complex relationships and boundaries between teeth, related anatomical features, and their associated pathology. Its images also provide us internal tooth morphology, periodontal ligament space, the presence or absence of periapicl lesions in association wi th critical anatomical structures and maxillary sinus involement. Using 3 D imaging makes it easier for clinicians to detect, diagnosis, and develop highly effective treatment plans. Now, 4 cases of periapical and periodontal pathosis with CBCT images are to be presented including periapical abscess, furcation involvement, periapical pathosis involving maxillary sinus, and osteomyelitis. CBCT analyze specific area of interest and provides the highly detailed anatomical information. It also facilitates earlier and more accurate diagnosis, and treatment planning decisions and more predictable outcome.

• International Journal of Oral Biology
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• 제41권4호
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• pp.225-230
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• 2016

Inflammation from chronic and acute infections of distal organs and tissues such as periodontitis is a risk factor for atherosclerotic vascular processes. Recently, a new model of atherosclerosis with vascular pathologies was developed in the Mongolian gerbil. In this study, we attempted to develop a model of ligature-induced periodontitis in gerbils and compared the characteristics of that periodontitis model with that in rats and mice. Each gerbil, rat, and mouse was randomly assigned to groups of control and periodontitis. A thread was placed around the cervix of the right and left first molars in the mandible with knots placed on the mesial side of each molar. At day 14 after the ligation, the animals were sacrificed and their mandibles were dissected. To measure alveolar bone loss along with inflammation, histopathological and micro-CT analyses were carried out. Gerbils showed tooth characteristics of deeper gingival crevice, longer cusp, longer root trunk and shorter root than those of rats and mice. The increased CEJ-ABC distance in distal and PDL area in furcation was also observed in ligated gerbils. An inflammatory response in the connective tissue under the junctional epithelium was also shown in all the animals. As a result, we confirmed the induction of periodontitis by ligature in the gerbils. We therefore consider the gerbil to be a useful model for investigating relationship between periodontitis and vascular disease in the same animal.

• 치과방사선
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• 제26권2호
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• pp.7-17
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• 1996

This study was performed to determine the postitional relationships of two lobes of parenchyma and to analysis the anatomical feature and its variations of duct on the panoramic views of the normal parotid glands in adults. Materials included 66 panoramic views and anterioposterior views of sialograms of selected persons and the radiograms of the gland experimentally reproduced on dry skull with lead foil and the reference images of computed tomograms of normal persons. Results were as follows : 1. On panoramic view of sialogram, the superficial lobe was revealed with totally being superimposed with the mandibular ramus and condyle and its tail portion superimposed with mandibular angle area, the deep lobe was revealed between the posterior border of the ramus and the mastoid process, and the isthmus was begin from the marked furcation off main duct and superimposed partially with the medial part of the deep lobe. 2, The mean length and the lateral extension of parenchyma was 63.18±8.05mm and 21.78±4.87mm respectively on panoramic view and showed no statistical relationship between them. 3. The main duct was generally perpendicular to the posterior border of ramus at middle portion and its configurations revealed 57,58％ of curvilinear type, 21.21％ sigmoid type, 15.15％ reverse sigmoid type. 4, The interlobular ducts of the deep lobe showed relatively well defined features between the mandibular ramus and the mastoid process.

• Journal of Periodontal and Implant Science
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• 제33권1호
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• pp.91-102
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• 2003

Several effective treatment methods and materials have been developed for the treatment of furcation involvement. Currently, the combination of guided tissue regeneration (GTR) and bone grafts is the most commonly prescribed method of treating furcation involved defects. But because these cases often present with poor accessibility, placement of the membrane may be difficult and consequently, clinically impractical. In this study, the alveolar bone healing patterns of adult beagle dogs presenting with alveolar bone destruction treated by one of two methods - treatment using solely bone allografts (BBP(R)), or treatment using bone allografts (BBP(R)) stabilized by a fibrin adhesive - were comp ared. The effects of the fibrin adhesive on the initial stabilization of the newly formed bone, subsequent regeneration of bone, and the feasibility of the clinical application of the fibrin adhesive were analyzed. The results of the study were as follows: 1. Clinical signs of inflammation at the 4-8 week interval were not observed: but signs of mild inflammation were histologically observed at the 4-week interval. 2. Allografts stabilized by fibrin adhesive showed good bone formation, whereas defects treated with only the allograft material showed incomplete alveolar bone regeneration. 3. Allografts stabilized by fibrin adhesive showed a decrease in the amount old bone with a concurrent increase in the formation of new lamellar bone four weeks post-op, whereas defects treated with only the allograft material showed no new lamellar bone formation at the same interval. 4. In detects treated with only the allograft material, the defective area was filled with connective tissue 8-weeks post-op, whereas fibrin adhesive stabilized allografts showed viable connections between the original bone and the newly formed bone, in addition to neovascularization 8-weeks post-op. The results of this study show that concurrent use of fibrin adhesive materials can stabilize the allograft material and aid in new bone formation Although the stability of fibrin adhesives fall short of the results achievable by GTR membranes, in cases presenting with poor accessibility that contraindicate the use of membranes, fibrin adhesive materials provide a viable and effective alternative to graft stabilization and new bone formation.

• Journal of Periodontal and Implant Science
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• 제51권6호
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• pp.374-385
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• 2021

Purpose: The aim of this study was to evaluate the effects of locally delivered 1% alendronate (ALN) gel used as an adjunct to non-invasive periodontal therapy. Methods: Ligature-induced periodontitis was performed in 96 rats. The ligature was tied in the cervical area of the mandibular left first molar. The animals were randomly divided into 4 groups: 1) NT, no treatment; 2) SRP, scaling and root planning; 3) SRP/PLA, SRP followed by filling the periodontal pocket with placebo gel (PLA); and 4) SRP/ALN, SRP followed by filling the periodontal pockets with 1% ALN gel. Histomorphometric (percentage of bone in the furcation region [PBF]) and immunohistochemical (receptor activator of nuclear factor-κB ligand, osteoprotegerin, and tartrate-resistant acid phosphatase) analyses were performed. Data were statistically analyzed, with the threshold of statistical significance set at P≤0.05. Results: The SRP, SRP/PLA, and SRP/ALN groups presented a higher PBF than the NT group (P≤0.01) at 7, 15, and 30 days. The SRP/ALN group presented a higher PBF than the SRP/PLA group in all experimental periods, as well as a higher PBF than the SRP group at 15 and 30 days. No differences were observed in the immunohistochemical analyses (P>0.05 for all). Conclusions: Locally delivered 1% ALN gel used as an adjunct to SRP enhanced bone regeneration in the furcation region in a rat model of experimental periodontitis.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.378-385
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• 2004

The purpose of this study was to compare the effects of preparation with GT files and profiles .04 in shaping of root canals and reconstruct the three-dimensional root canal system using micro computed tomography 40 canals of the extracted human mandibular molars were used, and randomly distributed into two experimental groups. In group 1. canals were prepared by GT files. In group 2, Profiles .04. were used. Apical preparation size was #30. For each tooth pre and post operative cross-sectional images were obtained by the micro CT at 50 micron intervals. Pre and post operative cross-sectional images of 1, 2, 3, 5, and 8mm from the apex were compared. For each section. canal area and centering ratio were determined. For each tooth pre- and post-operative root canal volume from the furcation to the apex of the roots was calculated by three-dimensional image software. Following results were obtained: 1. At 8mm from the apex, area of dentin removed by GT rotary file was significantly larger than that by Profile .04. And at the other levels there was not a significant difference. 2. There was a trend for GT rotary file to remain more centered in the canals than Profile .04 at all levels. But at 3mm level. there was a statistically significant difference. 3. In root canal volume increments after instrumentation, there was no significant difference between two groups.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.67-76
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• 1993

After periodontal surgery, the potential healing responses were occurred by interaction among junctional epithelium, gingival connective tissue, alveolar bone and periodontal ligament. The only cell that created periodontal regeneration was derived from periodontal ligament. The aim of the study was to evaluate the regenerative effects of the collagen membrane($collacote^{\circ}C$) and autogenous connective tissure graft with periosteum. Experimental periodontitis were created in furcation area of 4 adult dogs with bone removal and gutta percha packing. After 6 weeks later, the gutta percha was removed and experiment was performed divided by 3 groups. 1) Flap operation(control group). 2) Flap operation with collage membrane(Experimental group I). 3) Flap operation with autogenous connective tissue graft with periosteum (Experimental group II). After dogs were sacrificed after two and three weeks, specimens were prepared and stained with hematoxylin-eosin and masson-trichrome stain for light microscopic study. The results were as follows : 1. In all gruoups, connective tissue compartments were increased from two to three weeks especially in experimental group I. 2. Collagen membrane and connective tissue were increased collagen deposits of periodontal ligament. Therefore collagen fiber attached to tooth surface was seen. 3. In al experimental groups, newly forming alveolar bone was seen. 4. Collagen membrane and connective tissue were which prevented proliferation of epithelium, aided connective tissue new attachment and influenced periodontal regeneration.

• Journal of Periodontal and Implant Science
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• 제31권1호
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• pp.193-209
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• 2001

The prognosis of transplanted teeth is strongly related with periodontal healing. Several experimental studies showed that the application of enamel matrix derivatives on periodontitis-affected root surfaces resulted in periodontal regeneration. The purpose of this study was to determine the effect of enamel matrix derivatives on periodontitis-affected root surfaces prior to transplantation in dogs. Class III Furcation defects were surgically created on the left second, the third and the fourth premolar in the mandibles of nine mongrel dogs and experimental periodontitis was induced by placing small cotton pellets into defects for 3 weeks. Periodontitis-affected roots were treated by scaling and planing and the coronal portions were removed. Each root was extracted and implanted into recipient bed prepared in the contralateral premolar area. The transplanted roots were grouped according to the treatment modalities; Group I- roots treated with saline only, Group II- roots conditioned by neutral EDTA, and Group III- roots conditioned by neutral EDTA and enamel matrix derivatives ($EMDOGAIN^{(R)}$, BIORA Co., Sweden). The animals were sacrificed at 1 week, 3 weeks, and 10 weeks after transplantation and decalcified specimens were prepared for histologic examination. In Group I, healing was most frequently characterized by root resorption and ankylosis. In Group II, with root resorption and ankylosis in a few specimens, connective tissue attachment was partly seen on denuded root surface, but no cementum formation was seen. In Group III, there was regeneration by new cementum and periodontal ligament on denuded root surface, although slight root resorption and ankylosis were found in a few specimens. This result suggests that enamel matrix derivatives treatment on periodontitis-aggected root surface could reduce the frequency of root resorption and ankylosis and contribute to periodontal regeneration, and might be useful for autologous transplantation.

• 대한소아치과학회지
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• 제47권4호
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• pp.438-445
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• 2020

우상치는 수직적으로 긴 치수강과 근첨부에 위치하는 치수저를 특징으로 가지는 발육성 형태 이상이다. 이 연구의 목적은 어린이의 유구치에서 우상치의 유병률과 특징을 알아보기 위한 것이다. 이 연구는 2005년부터 2018년까지 연세대학교 치과대학병원 소아치과에 내원하여 파노라마 방사선 사진을 촬영한 만 5세에서 10세 사이의 환자 2,473명을 대상으로 시행되었으며 총 19,784개의 유구치가 평가되었다. 우상치의 유병률은 약 5.7%었고 남아에서 더 호발하였다. 또한 상악에서 6.3%, 하악에서 93.6%로 하악에서 현저히 높은 유병률을 보였다. 좌우에 따른 유병률의 차이는 나타나지 않았다. 우상치의 세부 유형으로 Daito의 방법을 적용하여 Hypertaurodontism, Mesotaurodontism, Hypotaurodontism으로 분류하였으며 각 유병률은 11.9%, 78.2%, 7.8%로 Mesotaurodontism이 가장 높은 유병률을 보였다.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.87-97
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• 1994

The ultimate goal of periodontal therapy is to fully reconstruct the periodontal attachment apparatus. Commonly used techniques for treatment of infrabony defects include a combination of root planing, curettage and root treatment. To prevent the apical migration of epithelial cells, the technique of guided tissue regeneration is used. The aim of this study is to compare the effects of root treatment with Citric acid & Tetracycline and Guided tissue regeneration in dogs. Experimental periodontitis was induced by the ligation of orthodontic elastic threads in the upper right and left premolars 3, 4 of five adult dogs for 6 weeks. 4 types of procedures were performed as follows; 1) Control graup : Mucoperiosteal flap 2) Experinental I : GTR used Gore-tex(R) membrane 3) Experinental II : Root treatment with citric acid (PHl) 4) Experinental III : Root treatment with tetracycline HCl (50mg/ml) There after, dogs were serially sacrificed at the 1, 2, 4, 5, 8 weeks, and the specimens were prepared, and stained with hematoxylin-eosin for the light microscopic evaluation. The results of this study were as follows; 1. Junctional epithelium reached to the notch through the furcation area in control group at 8 weeks. 2. In the aspects of the inflammatory cell infiltration, control group showed severe aggregation than experimental group I, II, III through the experimental period 3. New cementum was observed over the notch from 5 weeks in experimental group II 4. In the aspects of the amount of new bone formation, experimental group was better than control group, but there was not significant differences among the experimental group, I, II, III