• The Journal of Korean Academy of Prosthodontics
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• v.30 no.4
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• pp.582-610
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• 1992

The long-term success of any dental implant is dependent upon the optimization of stresses which occur during oral function and parafunction. Especially, it has been suggested that there is an unique set of problems associated with joining an osseointegrated implant and a natural tooth with a fixed partial denture. For this particular case, although many literatures suggest different ways to avoid high stress concentrations on the bone surrounding the implant under static and dynamic loading conditions, but few studies on the biomechanical efficacy of each assertion have been reported. The purpose of this investigation was to evaluate the efficacies of clinically suggested methods on stress distribution under static load and shock absorption under dynamic load, using two dimensional finite element method. In FEM models of osseointegrated implant-natural tooth supported fixed partial dentures, calculations were made on the stresses in surrounding bone and on the deflections of abutments and superstructure, first, to compare the difference in stress distribution effects under static load by the flexure of fastening screw or prosthesis, or intramobile connector, and second, to compare the difference in the shock absorption effects under dynamic load by intramobile connector or occlusal veneering with composite resin. The results of this analysis suggest that : 1. Under static load condition, using an implant design with fastenign screw connecting implant abutment and prosthesis or increasing the flexibility of fastening screw, or increasing the flexibility of prosthesis led to the .increase in height of peak stresses in cortical bone surrounding the implant, and has little effect on stress change in bone around the natural tooth. 2. Under static load condition, intramobile connector caused the substantial decrease in stress concentration in cortical bone surrounding the implant and the slight increase in stress in bone around the natural tooth. 3. Under dynamic load condition, both intramobile connector and composite resin veneering showed shock absorption effect on bone surrounding the implant and composite resin veneering had a greater shock absorption effect than intramobile connector.

• The korean journal of orthodontics
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• v.33 no.5 s.100
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• pp.399-405
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• 2003

Tooth movement facilitated by corticotomy and distraction osteogenesis, new paradigm in orthodontics, was discussed. Intrusive tooth movement of anterior or posterior teeth was thought to be difficult or impossible. In this study, a part of cortical bone, which was a sort of resistance to tooth movement in alveolar bone, was removed. On the other hand, active bone deposition was made possible in the tension side. That was the main concept of tooth movement facilitated by corticotomy and distraction osteogenesis. Teeth moved at such a speedy tate as we could not imagine in conventional tooth movement, which lead to the reduction of total treatment Period. And intrusive movement was Possible without a side effect, lot example, root resorption or the periodontal breakdown. Those were the superior aspects to the conventional orthodontics.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.673-693
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• 1994

Most adults, unlike growing children, have some periodontal problems which can influence the outcome of the orthodontic treatment. In cases where periodontal disease progression resulted in marked reduction of periodontium, orthodontic treatment could result in the worsening of the periodontal conditions, and therefore orthodontic treatment planning in such adult patients requires special considerations for the periodontal problems. This study investigates the effects of horizontal orthodontic tooth movement on the changes in the mesial, distal and furcation areas of the disease affected periodontium of adult dogs with advanced bone loss. Six adult dogs with healthy periodontium were selected, and mandibular 2nd premolars were extracted. In the mandibular 3rd premolars, angular bony defects in the mesial and distal sides, and horizontal bony defects in the furcation areas were created. Those that received the flap operation and plaque control were designated as the control, those that had horizontal tooth movement without plaque control after the flap operation as Experimental group I, those that had horizontal tooth movement under plaque control without the flap operation as Experimental group II, and those that had horizontal tooth movement under plaque control after the flap operation as Experimental group III. The control group was sacrificed 2 months postoperatively, and the experimental groups were sacrificed 5 months after the initiation of tooth movement. Specimens were histologically analyzed under light microscope. The results were as follows; 1. After the horizontal tooth movements, Experimental group I and II showed angular bony defects in the mesial sides of the roots and the distal side of the furcation areas, which correspond to the pressure sides. 2. After the horizontal tooth movements, Experimental group I and II showed decreased level of alveolar bone crest in the distal sides of the roots, which correspond to the tension sides. 3. Long junctional epithelium in the control group has not been replaced by periodontal connective tissue after the horizontal tooth movements. 4. Limited formation of new bone was observed in the angular bony defects in the mesial and distal aspects of the roots in the control group. 5. Inflammatory cell infiltration in the connective tissue was most severe in the Experimental group I, followed by Experimental group II, III, and the control group in that order. These results seem to indicate that plaque control was the most influencing factor in the alteration of the periodontal tissue after the horizontal tooth movements in the periodontal tissue with alveolar bone defects.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.109-115
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• 2011

Implants were placed after performing ridge expansion by inserting screws of gradually increasing thickness. Favorable clinical outcome was obtained. During surgery, buccal cortical plate fracture did not occur. Autogenous tooth bone graft material was grafted around the implant dehiscence defects and over the buccal cortical plate. The method involving the insertion of screws for ridge expansion is a successful and predictable technique for implant placement in narrow alveolar bone. Autogenous tooth bone graft material can be used for ridge augmentation and GBR.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.1
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• pp.33-39
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• 2021

When maxillary anterior tooth is extracted due to alveolar bone loss, the augmentation of alveolar ridge is very important for esthetic implant restoration. Because alveolar bone loss increases after extraction, the ridge preservation performed right after tooth extraction is meaningful for esthetic implant restoration. However, no achievement of primary closure during ridge preservation can negatively affect bone regeneration. To overcome this problem, we can use granulation tissue in the extraction socket for primary closure. This case report confirmed that primary closure using granulation tissue resulted in not only ridge preservation but also ridge augmentation by providing an environment more advantageous of bone regeneration than the open wound.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.528-538
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• 2014

PURPOSE. The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS. The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS. In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness ($0.07{\mu}m$ in Bio-Oss group Vs. $0.08{\mu}m$ in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness ($8.35{\mu}m$ in Bio-Oss group Vs. $13.12{\mu}m$ in AutoBT group) (P=.025). CONCLUSION. AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.143-153
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• 2017

One of the common complications of dental injury is tooth ankylosis. Unlike adults, when tooth ankylosis occurs in the adolescents, ankylosis interfered the growth of the adjacent alveolar bone, resulting in the developmental failure of the alveolar bone and subsequent open bite. The most common treatment option for ankylosed tooth is extraction. However, when prognosis of ankylosed tooth after extraction is expected to be poor due to severity of infrapositioning or prosthetic replacement cannot be performed immediately, various treatment options should be considered. This report suggests multidisciplinary treatment that might bring functionally and esthetically favorable result included alveolar bone distraction osteogenesis and decoronation of ankylosed maxillary anterior tooth with orthodontic and prosthetic treatments.

• The korean journal of orthodontics
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• v.44 no.6
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• pp.320-329
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• 2014

Objective: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. Methods: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). Results: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. Conclusions: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

• The Journal of Korean Academy of Prosthodontics
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• v.23 no.1
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• pp.13-37
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• 1985

Biocompatibility of dense synthetic hydroxylapatite is well known and the direct bond with adjacent bone developed. The purpose of this study was to evaluate the potential of clinical application of tooth ash for preservation of alveolar ridge. For this purpose the author performed an experimental implantation of the particulate and root form of both pure dense hydroxylapatite and tooth ash in alveolar sockets immediately after extraction. The pure dense hydroxylapatite was particulate form and root form made by Calciteck Inc. The tooth ash was prepared by incineration at $950^{\circ}C$, and the syrindrical form of the tooth ash was sintered and trimmed to fit the size of the each extraction socket of 10 mongrel dogs. After sugery the clinical, roentgenographical, and histological observation was carried out. The results obtained were as follows; 1. Clinical observation disclosed no dehiscence and exfoliation due to tissue rejection. 2. Vertical resorption of alveolar bone occurred in all experimental sockets as well as the control sites on the roentgenograph. 3. Osteoclastic activity appeared at the inner surfaces of the crestal alveolar bone on the 1st week but disappeared on the 2nd week. 4. There were macrophages in the particulate form on the 1st and 2nd week after surgery but no macrophages appered in the root form. S. New bone formation was developed from the bony wall of experimental sockets and grew to bond with the implant materials. In particulate form the new bone formation did not occur in central zone independently. 6. Tooth ash implant sites were covered with the newly formed bony trabeculation from third week, but Calcitite particles were covered with soft tissue. 7. Generally the healing occurred more rapidly in control sites than in implant sites.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.2.1-2.9
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• 2015

Background: The aim of this study was to evaluate the effect of autogenous tooth bone as a graft material for regeneration of bone in vertical bony defects of the minipigs. Material and Methods: Six minipigs were used in this study. Four molars were extracted in the right mandibular dentition and sent to the Korea Tooth Bank for fabrication of autogenous tooth bone. Ten days later, each extraction site was implanted with MS Implant Narrow Ridge $3.0{\times}10mm$ fixture (Osstem, Seoul, Korea) after standardized 2mm-sized artificial vertical bony defect formation. Pineappleshaped Root-On type autogenous tooth bones were applied to the vertical defects around the neck area of the posterior three fixtures and the fore-most one was not applied with autogenous bone as a control group. Each minipig was sacrificed at 4, 8, 12 weeks after fixture installation and examined radiologically and histologically. Histological evaluation was done under light microscope with Villanueva osteochrome bone staining with semi-quantitative histomorphometric study. Percentage of new bone over total area (NBF) and bone to implant contact (BIC) ratio were evaluated using digital software for area calculation. Result: NBF were $48.15{\pm}18.02%$, $45.50{\pm}28.37%$, and $77.13{\pm}15.30%$ in 4, 8, and 12 weeks, respectively for experimental groups. The control group showed $37.00{\pm}11.53%$, $32.25{\pm}26.99%$, and $1.33{\pm}2.31%$ in 4,8,12 weeks, respectively. BIC ratio were $53.08{\pm}19.82%$, $45.00{\pm}28.37%$, and $75.13{\pm}16.55%$ in 4,8,12 weeks, respectively. Those for the control groups were $38.33{\pm}6.43%$, $33.50{\pm}29.51%$, and $1.33{\pm}2.31%$ in 4, 8, 12 weeks, respectively. Conclusion: Autogenous tooth bone showed higher score than control group in NBF and BIC in all the data encompassing 4,8,12 weeks specimens, but statistically significant only 12 weeks data in both NBF and BIC.