• The korean journal of orthodontics
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• v.12 no.1
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• pp.7-14
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• 1982

In this study, effects of cyclophosphamide on the growth of the mandibular condyle head were investigated with Spraque-Dawley rats of the 28 days of age. Rats were devided into four groups. Three were used as experimental groups, and one as control. Each rat in experimental group was injected intraperitoneally with cyclophosphamide repeatedly three times, 20mg/kg for the first group, 40mg/kg for the second, and 60mg/kg for the third each time. Rats in control group were injected with physiological saline in the same method. Rats in each group were sacrificed at 5, 10, and 15 days following the last injection. The specimens were stained with H-E, toluidine blue, PAS, and alcian blue. The results were as follows; 1. In experimental group, with increasing the injection doses, the thickness of the condylar cartilage from the transitional zone to the hypertrophic zone became thinner than in control group. 2. Weaker metachromasia to toluidine blue and less positive reaction to PAS were seen. 3. In primary marrow cavity the fewer trabecular was formed, The direction of trabecular formation became obscuerer, and the lower density of bone was resulted in.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.525-530
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• 2004

Three dimensional finite element models of lumbar interbody fusion using rage and screws were constructed for the simulation of stress distribution and maximum displacement. It is also performed to investigate the efforts of osteoporosis and the location of cage on the stress distribution. It is known from the results that the increase of the strength of trabecular bone causes to decrease the stress of cortical bone and to increase the stress of trabecular bone. And it is found that the trend of stress distribution is changed by the change of location of cage and proper location of cage enhances the rate of operational success.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.418-425
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• 2006

Purpose: This study was aimed at evaluating the histological changes of new bone and expression of osteopontin (OPN) after mandibular distraction osteogenesis. Materials and Methods: Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in eight adult dogs. Two animals were sacrificed at 7, 14, 28 and 56 days after completion of distraction, respectively. The distracted bones and contralateral non-distracted control bones were harvested and processed for histological and immunohistochemical examinations. Results: The new bone was arranged to tension direction after distraction osteogenesis. 7 days after distraction, numerous osteoblasts lining the immature trabecular bone and fibroblast-like cells in the fibrous intrezone were observed. 14 days after distraction, the new formed trabecular bones were thickened compared with 7 days after distraction. 28 days after distraction, the fibrous interzone was almost filled with newly calcified bone, and it was more hardened at 56 days after distraction. Increased OPN signals detected in the osteoblasts lining the trabecular bone and fibroblast-like cells in the fibrous interzone at 7 and 14 days after distraction. At 28 days after distraction, the OPN was weakly expressed in the osteoblasts, and it was not detected in all cellular components of distracted bone at 56 days later of distraction. Conclusions: After distraction osteogenesis, the distracted zone was completely calcified during the 56 days of consolidation period. In this study, the staining intensity of OPN increased in the osteoblasts and fibroblast-like cells at 7 and 14 days after distraction. The expression pattern of this protein shown here suggested that OPN play an important role in the osteogenesis during the early consolidation period.

• Korean Journal of Oriental Medicine
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• v.6 no.1
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• pp.123-132
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• 2000

Bone is continuously remodeled during adult life with the resorption of old bone by osteoclasts and its subsequent replacement by osteoblast. Bone homeostasis is maintained by a balance between activities of osteoblasts and osteoclasts, but an imbalance between resorption and formation results in bone diseases including osteoporosis. Osteoblasts line up on the bone surface, especially regions of new bone formation, lay down bone matrix (osteoid) in orderly lamellae and induce its mineralization. Thus, the increased activity of osteoblasts is helpful to treat and prevent osteoporosis. In this study, we examined whether 80% EtOH extract of yukmijiwhang-whan is capable of affecting osteoblast proliferation using human osteoblast-like cell line, MG-63 and Saos-2. In an in vivo experiment, extract of yukmijiwhang-whan was administered for 9 weeks to ovariectomized (OVX) rats. At necropsy, uterus weights were measured, and trabecular bone areas (TBAS) of tibia and the sixth lumbar vertebra were measured by bone histomorphology. The maximum cell proliferation of MG-63 caused by extract of yukmijiwhang-whan at $5\;{\times}\;10^{-6}\;mg/ml$ was approximately 115% compared with control. In Saos-2, cell proliferation was approximately 145% of control at $5\;{\times}\;10^{-4}\;mg/ml$ and maximum alkaline phosphatase (ALP) activity was approximately 143% of control at $5\;{\times}\;10^{-5}\;mg/ml$. In animal study, however, the tibia and lumbar TBAS of the yukmijiwhang-whan group did not increased than the OVX control group. In conclusion, the 80% EtOH extract of yukmijiwhang-whan increased proliferation of osteoblasts but did not prevent bone loss in OVX rats.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.4
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• pp.359-370
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• 2011

To identify osseointegration of implants, dentists were performed the radiographic analysis. The fractal analysis methods using periapical radiographs before and after loading on implants was to evaluate whether or not significant. 30 patients who were placed implants in dental hospital of Wonkwang university were participated in this study. Total of 42 implants were analyzed. And, 14 males and 16 females aged from 22 to 73 participated in this study. The two morphologic and Fractal analysis of the one trabecular patterns in alveolar bone were done using periapical views. Two periapical views, after implant placement, and after 2 months of functional loading were analysed. The analysis was done by software, Image J(1.40s, National Institute of Health, Bethesda, USA). The data were statistically analyzed using one-way ANOVA(P<.05). Multiple comparison was done by the Tukey HSD test. The results of Fractal analysis and change in bone density around implants showed significantly different values, especially mandibles. However, in case of implants with failure, Fractal values decreased from 1.2865 to 1.1521 and 1.1135 to 1.0478.

• The Journal of Korean Medicine
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• v.29 no.3
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• pp.144-154
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• 2008

Objectives: Osteoporosis is one of the most common metabolic bone disorders in the menopausal stage, a disease signified by decrease of bone mass. The purpose of this study was to learn how Lycii Fructus influences SD rats with osteoporosis caused by the removal of the ovaries. Methods: After the removal of the ovaries from 24 female Sprague-Dawley rats, they were divided into a normal group, a control group, and a Lycii Fructus (25mg/100g) administration group. After 8 weeks, the rats were sacrificed and their weights, albumin, AST, ALT, ALP, total-cholesterol, triglyceride, P, Ca, T4, E2, weight of a femur, ash content of the tibia, and area and thickness of trabecular bone were measured. Results: Regarding the density of ALT, ALP, and estradiol from serum, the Lycii Fructus group was significantly decreased compared to the control group, and the density of phosphorous and calcium also decreased slightly. Moreover, albumin, triglyceride, and T4 showed an increasing propensity, but AST and total-cholesterol showed a decreasing propensity, but not significant. Regarding the variation of bone, femur weight and ash content of tibia, the Lycii Fructus group was increased compared to the control group but significance wasn't shown. The Lycii Fructus group increased significantly over the control group in area and thickness of trabecular bone and osteoclast number. Conclusions: From the results of the above study, Lycii Fructus should be effective for osteoporosis treatment and prevention.

• Journal of Biomedical Engineering Research
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• v.23 no.6
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• pp.451-458
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• 2002

Osteoporosis is a systemic skeletal disease caused by low bone mass and the decrease of bone density in the microstructure of trabecular bone. Drug therapy(PTH Parathyroid hormone) may increase the trabecular thickness and thus bone strength. Vertebroplasty is a minimally invasive surgery foy the treatment of osteoporotic vertebral compression fracture. This Procedure includes Puncturing vertebrae and filling with Polymethylmethacrylate(PMMA). Although altering recommended monomer-to-Powder ratio affects material properties of bone cement, clinicians commonly alter the mixture ratio to decrease viscosity and increase the working time. The Purposes of this study were to analyze the effect of 4he monomer-to-powder ratio on the mechanical characteristics of trabecular. In this paper, the finite element model of human vertebral trabecualr bone was developed by modified Voronoi diagram, to analyze the relative effect of hormone therapy and vertebroplasty at the treatment of osteoporotic vertebrae. Trabeuclar bone models for vertebroplasty with varied monomer-to-Powder ratio(0.40∼1.07 ㎖/g) were analyzed. Effective modulus and strength of bone cement-treated models were approximately 60% of those of intact models and these are almost twice the values of hormone-treated models. The bone cement models with the ratio of 0.53㎖/g have the maximum modulus and strength. For the ratio of 1.07㎖/g, the modulus and strength were minimum(42% and 49% respectively) but these were greater than those for drug therapy. This study shows that bone cement treatment is more effective than drug therapy. It is found that in vertebroplasty, using a monomer-to-powder ratio different from that recommended by manufacturer nay significantly not only reduce the cement's material Properties but also deteriorate the mechanical characteristics of osteoporotic vertebrae.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.117-124
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• 2006

Purpose: This study was aimed at elucidating the pathogenesis of talar osteochondral lesion by analyzing the histopathological findings. Materials and Methods: Twenty specimens from 20 patients who underwent surgical treatment for talus osteochondral lesions were studied. Preoperative MRI images including T1, T2, and stir images were taken and cases were classified according to modification of the Anderson's classification. There were 5 cases of MRI group 1, 6 cases of group 2, 7 cases of group 3 and 2 cases of group 4. A full thickness osteochondral plug including the osteochondral lesion of the talus was harvested from each patient and reviewed histopathologic changes of osteochondral fragment using H-E staining. Mean diameter of specimens was 8.5 mm and mean depth was 10.3 mm. Pathologic changes of articular cartilage and subchondral bone were observed. Subchondral bone was divided into superficial, middle and deep zones according to depth. Cartilage formation, trabecular thickening and marrow fibrosis were observed in each zone. Results: There were detachment of the joint cartilage at the tidemark in 16 cases of 20 cases and the separated cartilages were almost necrotic on the histopathologic findings. Cartilage formation within subchondral bone was discovered beneath the tidemark in 12 cases. Trabeculae were increased and thickened in 17 cases. These pathologic changes were similar to fracture healing process and these findings were more conspicuous near the tidemark and showed transition to normal bone marrow tissue with depth. No correlation between the pathological progression and MRI stages was found. A large cyst shown on MRI's was microscopically turned out to be multiple micro-cysts accompanied by fibrovascular structure and newly formed cartilage tissue. Conclusion: The histopathologic findings of osteochondral lesions are detachment of overlying cartilage at the tidemark and subsequent changes of subchondral bone. Subchondral bone changes are summarized as cartilage formation, marrow fibrosis and trabecular thickening that mean healing process following repeated micro fractures of trabecular. These osteochondral lesions should have differed from osteochondral fractures.

• Imaging Science in Dentistry
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• v.50 no.3
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• pp.199-208
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• 2020

Purpose: This study was performed to introduce an in vivo hybrid multimodality technique involving the coregistration of micro-computed tomography (micro-CT) and high-resolution magnetic resonance imaging (HR-MRI) to concomitantly visualize and quantify mineralization and vascularization at follow-up in a rat model. Materials and Methods: Three adult female rats were randomly assigned as test subjects, with 1 rat serving as a control subject. For 20 weeks, the test rats received a weekly intravenous injection of 30 ㎍/kg zoledronic acid, and the control rat was administered a similar dose of normal saline. Bilateral extraction of the lower first and second molars was performed after 10 weeks. All rats were scanned once every 4 weeks with both micro-CT and HR-MRI. Micro-CT and HR-MRI images were registered and fused in the same 3-dimensional region to quantify blood flow velocity and trabecular bone thickness at T0 (baseline), T4 (4 weeks), T8 (8 weeks), T12 (12 weeks), T16 (16 weeks), and T20 (20 weeks). Histological assessment was the gold standard with which the findings were compared. Results: The histomorphometric images at T20 aligned with the HR-MRI findings, with both test and control rats demonstrating reduced trabecular bone vasculature and blood vessel density. The micro-CT findings were also consistent with the histomorphometric changes, which revealed that the test rats had thicker trabecular bone and smaller marrow spaces than the control rat. Conclusion: The combination of micro-CT and HR-MRI may be considered a powerful non-invasive novel technique for the longitudinal quantification of localized mineralization and vascularization.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.502-508
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• 2012

Quantitative ultrasound technologies for osteoporosis diagnosis measure ultrasonic parameters such as speed of sound(SOS) and normalized broadband ultrasound attenuation(nBUA) in the calcaneus (heel bone). In the present study, the dependences of SOS and nBUA on bone mineral density in the proximal femur with high risk of fracture were investigated by using 20 trabecular bone samples extracted from bovine femurs. SOS and nBUA in the femoral trabecular bone samples were measured by using a transverse transmission method with one matched pair of ultrasonic transducers with a center frequency of 1.0 MHz. SOS and nBUA measured in the 20 trabecular bone samples exhibited high Pearson's correlation coefficients (r) of r = 0.83 and 0.72 with apparent bone density, respectively. The multiple regression analysis with SOS and nBUA as independent variables and apparent bone density as a dependent variable showed that the correlation coefficient r = 0.85 of the multiple linear regression model was higher than those of the simple linear regression model with either parameter SOS or nBUA as an independent variable. These high linear correlations between the ultrasonic parameters and the bone density suggest that the ultrasonic parameters measured in the femur can be useful for predicting the femoral bone mineral density.