• 대한치주과학회:학술대회논문집
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• 2005.11a
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• pp.207-207
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• 2005

• 대한치주과학회:학술대회논문집
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• 2002.11a
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• pp.122-122
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• 2002

• 대한치주과학회:학술대회논문집
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• 2001.12a
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• pp.122-122
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• 2001

• 대한치주과학회:학술대회논문집
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• 2003.11a
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• pp.134-134
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• 2003

• Journal of the Korean Orthopaedic Association
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• v.55 no.2
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• pp.127-134
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• 2020

Purpose: The aims of this study were (1) to investigate the relationship between the characteristics of allogenic bone block and the compressive strength of an allogenic bone block measured by biomechanical experiments, and (2) to compare the maximum pressure load of allogenic bone block with the gap pressure measured at the high tibial opening osteotomy. Materials and Methods: Ten patients who provided informed consent for gap pressure measurements during opening wedge high tibial osteotomy (OWHTO) were included. The gap pressures were measured at 1 mm intervals while opening the osteotomy site from 8 mm to 14 mm. Seventeen U-shaped allogenous wedge bone blocks were made from the femur, tibia, and humerus. The height, width, cross-sectional area, and cortex thickness of the bone blocks were measured, along with the maximum compressive load just before breakage. The relationship between these characteristics and the maximum pressure load of the bone blocks was evaluated. The gap pressures measured in OWHTO were compared with the maximum pressure loads of the allogenous wedge bone blocks to evaluate the possibility of inserting allogenous wedge bone blocks into the osteotomy site without a distractor in OWHTO. Results: The OWHTO gap pressure increased with increasing osteotomy site opening. The mean gap pressure, which occurred at a 14-mm opening, was 282±93 N; the maximum pressure was 427 N. The maximum pressure load of the allografts was 13,379±6,469 N (minimum, 5,868; maximum, 29,130 N) and was correlated significantly with the cortical bone thickness (correlation coefficient=0.693, p=0.002) and cross-sectional area (correlation coefficient=0.826, p<0.001). Depending on the sterilization method, the maximum pressure loads for the bone blocks were 13,406±5,928 N for freeze-dried and 13,348±7,449 N for fresh frozen. The maximum compressive load of the allogenous wedge bone blocks was 13.7-times greater than that in OWHTO opened to 14 mm (5,868 N vs. 427 N). Conclusion: The compressive strength of allogenous wedge bone blocks was sufficiently greater than the gap pressure in OWHTO. Therefore, allogenous wedge bone blocks can be inserted safely into the osteotomy site without a distractor.

• The Journal of Advanced Prosthodontics
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• v.1 no.1
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• pp.19-25
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• 2009

STATEMENT OF PROBLEM. Primary stability at the time of implant placement is related to the level of primary bone contact. The level of bone contact with implant is affected by thread design, surgical procedure and bone quality, etc. PURPOSE. The aim of this study was to compare the initial stability of the various taper implants according to the thread designs, half of which were engaged to inferior cortical wall of type IV bone(Group 1) and the rest of which were not engaged to inferior cortical wall(Group 2) by measuring the implant stability quotient(ISQ) and the removal torque value(RTV). MATERIAL AND METHODS. In this study, 6 different implant fixtures with 10 mm length were installed. In order to simulate the sinus inferior wall of type IV bone, one side cortical bone of swine rib was removed. 6 different implants were installed in the same bone block following manufacturer s recommended procedures. Total 10 bone blocks were made for each group. The height of Group 1 bone block was 10 mm for engagement and that of group 2 was 13 mm. The initial stability was measured with ISQ value using Osstell $mentor^{(R)}$ and with removal torque using MGT50 torque gauge. RESULTS. In this study, we found the following results. 1. In Group 1 with fixtures engaged to the inferior cortical wall, there was no significant difference in RTV and ISQ value among the 6 types of implants. 2. In Group 2 with fixtures not engaged to the inferior cortical wall, there was significant difference in RTV and ISQ value among the 6 types of implants(P < .05). 3. There was significant difference in RTV and ISQ value according to whether fixtures were engaged to the inferior cortical wall or not(P < .05). 4. Under-drilling made RTV and ISQ value increase significantly in the NT implants which had lower RTV and ISQ value in Group 2(P < .05). CONCLUSIONS. Without being engaged to the inferior cortical wall fixtures had initial stability affected by implant types. Also in poor quality bone, under-drilling improved initial stability.

• Journal of IKEEE
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• v.24 no.3
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• pp.791-796
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• 2020

In this paper, "Q-Bone", a 3^rd generation blockchain platform with enhanced security and flexibility, was developed. As a 3^rd generation blockchain platform, it exploits BP (block producer) to increase processing speed. It has many advantages as follows. It improves both security and speed by mixing RSA (Rivest-Shamir-Adleman) and AES (advanced encryption standard). It improves flexibility by exploiting gateway to convert between apps and blockchain with different programming language. It increases processing speed by combining whole transactions into one block and distribute it when too many transactions occur. It improves search speed by inserting sequence hash into transaction data. It was implemented and applied to pet communication service and academy-instructor-student matching service, and it was verified to work correctly and effectively. Its processing speed is 3,357 transactions/second, which shows excellent performance.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.66-71
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• 1997

The all inside anterior cruciate ligament reconstruction technique places an anterior ligament substitutes within two bony sockets rather than hone tunnel. This approach is accomplished through arthroscopic three portal which avoids the surgical exposure and morbidity associated with creating traditional bone tunnel. This technique has several distinct advantages when compared with the traditional ACL reconstruction through the bone tunnels. It offers the surgeon a less morbid method for ACL reconstruction that positions an ACL substitute at the anatomic attachment sites of the original ACL with two bone sockets, obviating the need for traditional bone tunnels. Graft fixation at or near the anatomic attachment points of the original ACL minimizes creep with early range of motion and reduces the abrasive 'wind-shield wipe' motion of the graft which occur with bone plugs positioned inside bone tunnels. The sagittal posterior angle to the tibial socket increases fixation strength to pullout with anterior translation force for the tibia on the femur. This technique is not graft specific and can accomodate any graft in which graft length can be customized to the intraarticular native ACL length.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.303-311
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• 1999

In adult patients, the corrections of their malocclusion may be more difficult and require longer treatment time due to thicker layer of cortical bone and reduced blood supply. Recently, various methods such as surgery, implant for anchorage and corticotomy have been tried to overcome these problems. Corticotomy is a surgical technique in which a fissure is made through the cortical bone that surrounds a tooth so that the tooth is embedded within a block of bone that is connected to adjacent blocks through only the medullary bone. Technique of corticotomy has been widely used for correction of maxillary transverse deficiency, but hasn't actively in other fields of orthodontics. We applied corticotomies in many types of orthodontic treatment and had satisfactory results. We suggested clinical application of corticotomy in adult orthodontics to reduce treatment period and to achieve better stability after orthodontic treatment.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.442-449
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• 1998

Freeze-dried cortical bones of the goat were transplanted to the experimental fibular defect of 10 dogs for valuating the possibility of xenogeneic bone implantation and the specificity of BM(Bone Morphogenetic Protein). The . freeze-dried cortical bone eliminated antigens and defatted with chloroform and methanol were freeze-dried at $-80{\circ}C$ for preservation of BMP and then sterilized with 50 gas and storaged in room temperature. Ten freeze-dried cortical implants of the goat were transplanted in experimentally defected regions of bilateral fibula of 5 dogs in clinically normal. The transplanted region had been radiographed for observing state of bone union and BALPOone Alkaline Phosphatase) in the serum of the host was measured for valuating activity of oteoblast per 2 week-interval after transplant procedures. New bone formation had been observed early in one of ten regions around implants about the same time as autoimplant regions. It was incorporated with its host bone during 4-12 weeks after transplantation. In another 2 cases of 2 dogs, new bone formation and absorption of implant had been observed from 4 weeks but they were not incorporated completely until 20 weeks. The rest of the freeze-dried bone implants, 7 cases of 4 dogs had not been observed new bone formation nor absorption of implants. The freeze-drying method for implants means to not influence bone incorporation. Although less of union percentages the union form of this experiment were similar to alloimplantation and it may mean to block immunity reaction that disturbs the bone induction by BMP. It demonsknted that the possibility of the xenogenous bone implantation is recognized by reason of the low specificity of BMP between goat and dog.