• Archives of Pharmacal Research
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• v.26 no.11
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• pp.917-924
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• 2003

This research aims to test a new drug candidate based on a traditional medicinal herb, F1, an herbal extract obtained from Astragalus membranaceus and its main ingredient, 1-monolinolein that may have fewer side effects and less uterine hypertrophy. In vitro experiments, human osteoblast-like cell lines, MG-63 and Saos-2, were analyzed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and an alkaline phosphatase (ALP) assays. Mouse osteoclasts were induced through a calcium-deficient diet and inhibition effects were measured. In vivo experiments were done using ovariectomized (OVX) rats for 9 weeks. At necropsy, uterus weights were measured, trabecular bone area (TBA) of tibia and lumbar vertebra were measured bone histomorphology. In results, cell proliferation and ALP activity in Saos-2 by ether F1 or 1-monolinolein did not increased significantly compared to the control. The F1 inhibited osteoclast development ($IC_{25}=3.37{\times}10^{-5}$mg/mL) less than 17$\beta$-estradiol. The OVX rats administered F1 (2 mg/kg/day and 10 mg/kg/day) showed an increase in TBA of the tibia significantly (136.3${\pm}4.2% and 138.5{\pm}$10.3% of control). In conclusions, the herbal extract, F1 inhibited tibia and lumbar bone loss and did not cause uterine hypertrophy. However, 1-monolinolein, the main ingredient of the herbal extract, did not inhibit bone loss.

• Journal of Korean Neurosurgical Society
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• v.54 no.5
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• pp.384-389
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• 2013

Objective : Use of quantitative computed tomography (CT) to evaluate bone mineral density was suggested in the 1970s. Despite its reliability and accuracy, technical shortcomings restricted its usage, and dual-energy X-ray absorptiometry (DXA) became the gold standard evaluation method. Advances in CT technology have reduced its previous limitations, and CT evaluation of bone quality may now be applicable in clinical practice. The aim of this study was to determine if the Hounsfield unit (HU) values obtained from CT correlate with patient age and bone mineral density. Methods : A total of 128 female patients who underwent lumbar CT for back pain were enrolled in the study. Their mean age was 66.4 years. Among them, 70 patients also underwent DXA. The patients were stratified by decade of life, forming five age groups. Lumbar vertebrae L1-4 were analyzed. The HU value of each vertebra was determined by averaging three measurements of the vertebra's trabecular portion, as shown in consecutive axial CT images. The HU values were compared between age groups, and correlations of HU value with bone mineral density and T-scores were determined. Results : The HU values consistently decreased with increasing age with significant differences between age groups (p<0.001). There were significant positive correlations (p<0.001) of HU value with bone mineral density and T-score. Conclusion : The trabecular area HU value consistently decreases with age. Based on the strong positive correlation between HU value and bone mineral density, CT-based HU values might be useful in detecting bone mineral diseases, such as osteoporosis.

• Journal of Korean Neurosurgical Society
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• v.52 no.5
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• pp.435-440
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• 2012

Objective : The purpose of this study is to find the optimal stiffness and volume of bone cement and their biomechanical effects on the adjacent vertebrae to determine a better strategy for conducting vertebroplasty. Methods : A three-dimensional finite-element model of a functional spinal unit was developed using computed tomography scans of a normal motion segment, comprising the T11, T12 and L1 vertebrae. Volumes of bone cement, with appropriate mechanical properties, were inserted into the trabecular core of the T12 vertebra. Parametric studies were done by varying the volume and stiffness of the bone cement. Results : When the bone cement filling volume reached 30% of the volume of a vertebral body, the level of stiffness was restored to that of normal bone, and when higher bone cement exceeded 30% of the volume, the result was stiffness in excess of that of normal bone. When the bone cement volume was varied, local stress in the bony structures (cortical shell, trabecular bone and endplate) of each vertebra monotonically increased. Low-modulus bone cement has the effect of reducing strain in the augmented body, but only in cases of relatively high volumes of bone cement (>50%). Furthermore, varying the stiffness of bone cement has a negligible effect on the stress distribution of vertebral bodies. Conclusion : The volume of cement was considered to be the most important determinant in endplate fracture. Changing the stiffness of bone cement has a negligible effect on the stress distribution of vertebral bodies.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.150-155
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• 2006

Purpose: The purpose of this study is to assess the results of the autologous osteochondral grafting harvested from medial side of talus for relatively large osteochondral lesion of the medial talar dome. Materials and Methods: From October 2004 to September 2005, 12 patients with osteochondral lesion measured more than 10 mm in axial MRI who were followed up more than 1 year after operation were analyzed. We evaluated postoperative symptoms by Mann and Reynolds scale, morbidity of donor site, and compared the range of both ankle motion. We also evaluated the union at the medial malleolar osteotomy site, trabecular connection between the grafted osteochondral mass and talus, irregularity of the articular surface in lesion. Results: Clinical results were rated as excellent in 4, good in 7, fair in 1. The mean angle of the total range of motion in affected ankle was decreased by 3 degrees compared to that in unaffected ankle. We did not observe abnormal findings at donor site. The osteotomized bone was united at mean 9 weeks (range, 8-12 weeks). We observed trabecular connection between grafted osteochondral mass and talus at mean 14 weeks (range, 12-16 weeks). We also observed irregular articular surface in osteochondral lesions in 6, smooth articular surface in 6. Conclusion: The local autologous osteochondral graft for relatively large osteochondral lesion of the medial talar dome is useful operative method with advantages of wide operative field, low morbidity of donor site, and high satisfaction rate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.183-184
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• 2006

Some researchers proposed positive effects of whole body vibration (WBV) on osteoporotic trabecular bones of animals. In the present study, the correlation between the improvement of morphological characteristics and the effect of WBV was investigated and analyzed in OVX rats. The rats were randomly assigned to 5 groups: control, sham, WBV 17Hz, WBV 30Hz and WBV 45Hz. The WBV groups were exercised on a vibration platform (magnitude : $1mm_{peak-peak}$, frequency : 17Hz, 30Hz and 45Hz, 30 minutes/day for 5 days/week). The 4th lumbar on rats was scanned by In-vivo Micro-CT at the week 0(just before WBV) and the week 8(after WBV). Structural parameters of the 4th lumbar, based on two dimensional (2D) scan image data, were investigated and analyzed. The quantitative decrement rate of trabecular bone on WBV groups with 30Hz and 45Hz were lower than control and sham groups. The results showed the positive effect of WBV on osteoporotic bones of OVX rats.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.649-650
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• 2006

Some researchers proposed positive effects of whole body vibration (WBV) on osteoporotic trabecular bones of animals. In the present study, the correlation between the improvement of morphological characteristics and the effect of WBV was investigated and analyzed in OVX rats. The rats were randomly assigned to 5 groups: control, sham, WBV 17Hz, WBV 30Hz and WBV 45Hz. The WBV groups were exercised on a vibration platform (magnitude $1mm_{peak-peak}$, frequency : 17Hz, 30Hz and 45Hz, 30 minutes/day for 5 days/week). The 4th lumbar on rats was scanned by In-vivo Micro-CT at the week 0(iust before WBV) and the week 8(after WBV). Structural parameters of the 4th lumbar, based on two dimensional (2D) scan image data, were investigated and analyzed. The quantitative decrement rate of trabecular bone on WBV groups with 30Hz and 45Hz were lower than control and sham groups. The results showed the positive effect of WBV on osteoporotic bones of OVX rats.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.21-32
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• 1999

Purpose: To evaluate the effect of variable scanning protocols of computed tomography for evaluation of pre-implant site of the mandible through the comparison of the reformatted cross-sectional images of helical CT scans obtained with various imaging parameters versus those of conventional CT scans. Materials and Methods: A dry mandible was imaged using conventional nonoverlapped CT scans with 1 mm slice thickness and helical CT scans with 1 mm slice thickness and pitches of 1.0, 1.5. 2.0, 2.5 and 3.0. All helical images were reconstructed at reconstruction interval of 1 mm. DentaScan reformatted images were obtained to allow standardized visualization of cross-sectional images of the mandible. The reformatted images were reviewed and measured separately by 4 dental radiologists. The image qualities of continuity of cortical outline. trabecular bone structure and visibility of the mandibular canal were evaluated and the distance between anatomic structures were measured by 4 dental radiologists. Results: On image qualities of continuity of cortical outline. trabecular bone structure and visibility of the mandibular canal and in horizontal measurement. there was no statistically significant difference among conventional and helical scans with pitches of 1.0. 1.5 and 2.0. In vertical measurement. there was no statistically significant difference among the conventional and all imaging parameters of helical CT scans with pitches of 1.0, 1.5, 2.0, 2.5 and 3.0. Conclusion: The images of helical CT scans with 1 mm slice thickness and pitches of 1.0, 1.5 and 2.0 are as good as those of conventional CT scans with 1 mm slice thickness for evaluation of predental implant site of the mandible. Considering the radiation dose and patient comfort, helical CT scans with 1 mm slice thickness and pitch of 2.0 is recommended for evaluation of pre-implant site of the mandible.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.1
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• pp.75-87
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• 2006

The purpose of this study was to investigate the effects of prostheses misfit, cantilever on the stress distribution in the implant components and surrounding bone using three dimensional finite element analysis. Two standard 3-dimensional finite element models were constructed: (1) 3 ITI implant supported, 3-unit fixed partial denture and (2) 3 ITI implant supported, 3-unit fixed partial denture with a distal cantilever. variations of the standard finite element models were made by placing a $100{\mu}m$ or $200{\mu}m$ gap between the fixture, the abutment and the crown on the second premolar and first molar. Total 14 models were constructed. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the distal marginal ridge of the distal molar. von Mises stresses were recorded and compared in the crowns, abutments, crestal compact bones, and trabecular bones. The results were obtained as follows: 1. In the ITI implant system, cement-retained prostheses showed comparatively low stress distributions on all the implant components and fixtures regardless of the misfit sizes under vertical loading. The stresses were increased twice under oblique loading especially in the prostheses with cantilever, but neither showed the effects of misfit size. 2. Under the oblique loading and posterior cantilever, the stresses were highly increased in the crestal bones around ITI implants, but effects of misfit were not shown. Although higher stresses were shown on the apical portion of trabecular bones, the effects by misfit were little and the stresses were increased by the posterior cantilever. 3. When the cement loss happened in the ITI implant supported FPD with misfit, the stresses were increased in the implant componets and supporting structures.

• The Journal of Korean Medicine
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• v.19 no.1
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• pp.5-18
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• 1998

The purpose of this study was to determine the effects of aqua-acupuncture of Laennec N HO (Hominis placenta Cervi pontotrichum cornu Carthami semen). on trabecular area and physiological change in ovariectomized osteoporotic rats. This experiment was performed to .investigate an antiosteoporosis. effects of Laennec N HO(Hominis placenta Cervi pontotrichum cornu Carthmi semen) aqua-acupuncture on the osteoporosis induced by both ovariectomy in Rats. So rats were divided into Sham group and OVX group. OVX groups were divided into control group, Exp. I group, Exp II group and Exp III group). The Ratios of trabecular area seen in ephiphysis and diaphysis of tibia and lumbar vertebral body and physiological change were as follows. 1. In the proximal ephiphysis of tibia, Exp I II III groups were significantly increased compared to that in control group (p<0.05). 2. In the diaphysis of tibia, Exp III group were significantly increased compared to that in control group (p<0.05). 3. In the first lumbar vertebral body, Exp II group were significantly increased compared to that in control group. 4. In the cortical thickness index of tibia, Exp III III groups were significantly increased compared to that in control group. 5. Osteoca1cin was increased in the Exp II group than those of other Experiment groups and control group, and Phosphorus was decreased in the Exp I II group than that in control group, But a significant difference was not seen. GOT, GPT and Alkaline phosphatase were decreased in all Experiment groups than that in control group. But a significant difference was not seen. From the above results, it might be suggested that aqua-acupuncture Laennec N HO(Hominis placenta Cervi pontotrichum cornu Carthami semen) prevented the increase in bone turnover and the decrese in bone mass induced by OVX in rats.

• Imaging Science in Dentistry
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• v.40 no.3
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• pp.137-142
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• 2010

Purpose : This study was performed to evaluate the diagnostic ability of ultrasonography in detection of bone defects and new bone formation. Materials and Methods : Experimental bony defects were prepared on the parietal bone samples acquired from 3.5 kg New Zealand male rabbits. The defects were evaluated using ultrasonography and CBCT, and examined histologically at interval of 1, 3, 6, and 8 weeks. Results : Ultrasonograph demonstrated hyperechogenicity in the defect area at 3 weeks and broadened hyperechogenicity from the margin of bone defect at 6 and 8 weeks due to new bone formation. On the CBCT images, new bone formation was first observed at 3 weeks around the margin of the defect, and showed gradually increase at 6 and 8 weeks. Histologic findings revealed existence of the fibroblasts and fibrous connective tissue with abundant capillary vessels only at 1 week, but osteoid tissue and newly formed trabecular bone at 3 weeks. Bone remodeling in the defect area was observed at 6 weeks and increased calcification and dense trabecular bone formation was observed at 8 weeks. Conclusions : Ultrasonograph proved to be a very useful diagnostic tool in detecting the bony defect and new bone formation. Additionally, ultrasonography provided valuable information regarding the blood supply around the defect area.