• The Journal of Korean Academy of Prosthodontics
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• v.53 no.2
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• pp.120-127
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• 2015

Purpose: The aim was to investigate the effect of implant thread designs on the stress dissipation of the implant. Materials and methods: The threads evaluated in this study included the V-shaped, buttress, reverse buttress, and square-shaped threads, which were of the same size (depth). Building four different implant/bone complexes each consisting of an implant with one of the 4 different threads on its cylindrical body ($4.1mm{\times}10mm$), a force of 100 N was applied onto the top of implant abutment at $30^{\circ}$ with the implant axis. In order to simulate different osseointegration stages at the implant/bone interfaces, a nonlinear contact condition was used to simulate immature osseointegration and a bonding condition for mature osseointegration states. Results: Stress distribution pattern around the implant differed depending on the osseointegration states. Stress levels as well as the differences in the stress between the analysis models (with different threads) were higher in the case of the immature osseointegration state. Both the stress levels and the differences between analysis models became lower at the completely osseointegrated state. Stress dissipation characteristics of the V-shape thread was in the middle of the four threads in both the immature and mature states of osseointegration. These results indicated that implant thread design may have biomechanical impact on the implant bed bone until the osseointegration process has been finished. Conclusion: The stress dissipation characteristics of V-shape thread was in the middle of the four threads in both the immature and mature states of osseointegration.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.1
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• pp.9-17
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• 2014

Purpose: The purpose of this study was to compare zirconia implants with titanium implants from the view point of biomechanical stability and histologic response on osseointegration when those were placed with xenograft materials. Materials and methods: Specimens were divided into two groups; the control group was experimented with eighteen titanium implants which had anodized surface and the experimental group was experimented with eighteen sandblasted zirconia (Y-TZP) implants. At the tibias of six pigs, implants were installed into bone defect sites prepared surgically and treated with resorbable membranes and bovine bone. Two pigs were sacrificed after 1, 4 and 12 weeks respectively. Each implant site was sampled and processed for histologic and histomorphometric analysis. The stability of implants was evaluated with a $Periotest^{(R)}$. And the interfaces between bone and the implant were observed with a scanning electron microscope. Results: In stability analysis there was no significant difference between Periotest values of the control group and the experimental group. In histologic analysis with a light microscope after 4 weeks, there was new bone formation with the resorption of bovine bone and the active synthesis of osteoblasts in both groups. In bone-implant contact percentage there was significant difference between both groups (P<.05). In bone area percentage there was no significant difference between both groups. In analysis of both groups with a scanning electron microscope there was a gap between bone and a surface at 4 weeks and it was filled up with bone formed newly at 12 weeks. Conclusion: When accompanied by xenograft using membrane, bone to implant contact percentage of zirconia implants used in this experiment was significantly less than that of the titanium implants by surface treatment of anodic oxidation. So, it is considered that the improvement of zirconia implant is needed through ongoing research on surface treatment methods for its practical use.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.30-41
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• 2007

Purpose: Bone metastasis in breast cancer patients are usually assessed by conventional Tc-99m methylene diphosphonate whole-body bone scan, which has a high sensitivity but a poor specificity. However, positron emission tomography with $^{18}F-2-deoxyglucose$ (FDG-PET) can offer superior spatial resolution and improved specificity. FDG-PET/CT can offer more information to assess bone metastasis than PET alone, by giving a anatomical information of non-enhanced CT image. We attempted to evaluate the usefulness of FDG-PET/CT for detecting bone metastasis in breast cancer and to compare FDG-PET/CT results with bone scan findings. Materials and Methods: The study group comprised 157 women patients (range: $28{\sim}78$ years old, $mean{\pm}SD=49.5{\pm}8.5$) with biopsy-proven breast cancer who underwent bone scan and FDG-PET/CT within 1 week interval. The final diagnosis of bone metastasis was established by histopathological findings, radiological correlation, or clinical follow-up. Bone scan was acquired over 4 hours after administration of 740 MBq Tc-99m MDP. Bone scan image was interpreted as normal, low, intermediate or high probability for osseous metastasis. FDG PET/CT was performed after 6 hours fasting. 370 MBq F-18 FDG was administered intravenously 1 hour before imaging. PET data was obtained by 3D mode and CT data, used as transmission correction database, was acquired during shallow respiration. PET images were evaluated by visual interpretation, and quantification of FDG accumulation in bone lesion was performed by maximal SUV(SUVmax) and relative SUV(SUVrel). Results: Six patients(4.4%) showed metastatic bone lesions. Four(66.6%) of 6 patients with osseous metastasis was detected by bone scan and all 6 patients(100%) were detected by PET/CT. A total of 135 bone lesions found on either FDG-PET or bone scan were consist of 108 osseous metastatic lesion and 27 benign bone lesions. Osseous metastatic lesion had higher SUVmax and SUVrel compared to benign bone lesion($4.79{\pm}3.32$ vs $1.45{\pm}0.44$, p=0.000, $3.08{\pm}2.85$ vs $0.30{\pm}0.43$, p=0.000). Among 108 osseous metastatic lesions, 76 lesions showed as abnormal uptake on bone scan, and 76 lesions also showed as increased FDG uptake on PET/CT scan. There was good agreement between FDG uptake and abnormal bone scan finding (Kendall tau-b : 0.689, p=0.000). Lesion showed increased bone tracer uptake had higher SUVmax and SUVrel compared to lesion showed no abnormal bone scan finding ($6.03{\pm}3.12$ vs $1.09{\pm}1.49$, p=0.000, $4.76{\pm}3.31$ vs $1.29{\pm}0.92$, p=0.000). The order of frequency of osseous metastatic site was vertebra, pelvis, rib, skull, sternum, scapula, femur, clavicle, and humerus. Metastatic lesion on skull had highest SUVmax and metastatic lesion on rib had highest SUVrel. Osteosclerotic metastatic lesion had lowest SUVmax and SUVrel. Conclusion: These results suggest that FDG-PET/CT is more sensitive to detect breast cancer patients with osseous metastasis. CT scan must be reviewed cautiously skeleton with bone window, because osteosclerotic metastatic lesion did not showed abnormal FDG accumulation frequently.

• The Journal of the Korean dental association
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• v.38 no.3 s.370
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• pp.225-231
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• 2000

• Journal of the Korean Society for Precision Engineering
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• v.19 no.4
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• pp.18-24
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• 2002

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.254-261
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• 2009

The maxillary sinus bone graft procedure is one of the predictable and successful treatments for the rehabilitation of atrophic and pneumatized edentulous posterior maxilla. Materials used for maxillary sinus floor augmentation include autogenous bone, allogenic bone, xenogenic bone and alloplastic materials. Among them, autogenous bone grafts still represents 'gold standard'for bone augmentation procedures. We selected the mandibular ramus area as a donor site for the autogenous bone graft because of low donor site morbidity. We performed maxillary sinus bone graft procedures with implant placement using particulated ramal autobone and bovine bone mixture, and got good results. This is a preliminary report of the maxillary sinus bone graft using particulated ramal autobone and bovine bone, requires more long-term follow up and further studies.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.125-130
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• 2008

Telangiectatic osteosarcoma is a rare variant of osteosarcoma. The rib is an uncommon primary site for conventional osteosarcoma, and even more for telangiectatic osteosarcoma. Because this tumor consists of single to multiple cystic cavities that contain blood or necrotic tumor with no appreciable areas of sclerosis, careful observation is needed to differentiate this malignancy from other benign cystic lesion. Therefore primary differential diagnosis including telangiectatic osteosarcoma is important, although rib is not the predilection site of telangiectatic osteosarcoma. We present a case of telangiectatic osteosarcoma arising in a rib. We reviewed the literature concerning telangiectatic osteosarcomas and primary osteosarcomas arising from the rib. The differential diagnosis of telangiectatic osteosarcoma and clinical features of osteosarcomas arising from unusual locations were discussed.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.114-117
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• 2016

In vivo labeling of bone with fluorochromes is a widely used method for assessment of bone formation and remodeling processes. In particular, calcein is used as a marker for identification of bone growth, which is indicated by a green color. Calcein green is a calcium chelator that adheres to regions of mineralizing bone thereby allowing localization of new bone. Bone formation and remodeling in vivo can be assessed by calcium-binding calcein labeling. In this study, changes in the femoral bone of a normal mouse model at both 4 and 8 weeks were evaluated using calcein labeling. Intense deposition of calcium in the bone was observed after application for 8 weeks. A mouse model is suitable for application in in vivo experiments using genetically modified mice, such as knock-out mice, however data regarding femoral cross sectional bone in young mice are limited. The current study confirmed calcein as a useful marker for identification of bone growth, which was indicated by a green color on photomicrographs. This methodological process may provide basic information for interpreting bone formation and regeneration to pharmacologic or genetic manipulation in mice.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.185-189
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• 2007

Advancement of imaging and surgical technique makes the internal hemipelvectomy one of the routine procedures of pelvis sarcoma. However, optimal reconstructive option for skeletal defect is still controversial. Pasteurized autogenous bone-total hip composite is a biologic method and its anatomical appropriateness gives good indication for selected cases. Nevertheless, in case of complication such as infection or mechanical breakage, removal of hardware including graft is inevitable. In those cases, marked limb length discrepancy induce marked functional deficit. To overcome this problem, the authors report 1 case, refining previous technique, saving the femoral head and reinsertion of osteoarticularly pasteurized host bone.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1453-1463
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• 2015

The purpose of this study was to identify health behaviors of elderly with osteoarthritis across gender groups. Total of 1,654 age 65 over from the fifth Korean National health and Nutrition Examination Survey (KNHANES) were selected. The data analysis was performed using the complex sampling function of SPSS version 20. Logistic regression analysis shows the difference of risk factors of osteoarthritis between men and women elderly people. Prevalence of osteoarthritis in men elderly was associated with drinking, education for osteoarthritis, and treatment of osteoarthritis whereas the factors in woman elderly were depression and muscle strengthen exercise. Most of the subjects had not the opportunity of education of the management of the osteoarthritis. These findings from the study are expected to promote the screening strategy for the aged at risk of osteoarthritis in the Korean community and enhance the effect of the nursing intervention for the elderly with osteoarthritis.