• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.155-163
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• 2000

Osteoporosis is the consequence of an imbalance between osteoclastic and osteoblastic activity, coupled with an increased rate of bone turnover observed with menopause. Estrogen is generally considered to maintain bone mass through suppression of bone resorption. The purpose of this study was to evaluate the rat femoral trabecular change not only in the deficiency of estrogen but also in the administration of estrogen following ovariectomy(OVX). 30 female Sprague-Dawley rats were subjected to bilateral OVX or sham surgery(control). Groups of OVX were divided into 4 groups. The first group was injected daily with vehicle alone for 20 days after 20 weeks following OVX. The additional groups of OVX was injected daily with low, medium, or high doses of $17{\beta}-estradiol$(10, 25 or $50{\mu}g/kg$ BW, respectively). All rats were sacrified 23 weeks after OVX, and their femur were processed for H&E, MT stain and histomorphometry. The results were as follows; 1. In the histomorphometric analysis, the trabecular bone volume/tissue volume, trabecular thickness and trabecular seperation were respectively $31.2{\pm}8.3%$, $54.3{\pm}4.8{\mu}m$ and $280.7{\pm}16.4{\mu}m$ in vehicle treated OVX group and $48.6{\pm}7.3%$, $90.4{\pm}4.5{\mu}m$ and $126.3{\pm}5{\mu}m$ in sham operation group, and they showed statistical significance compare to control group. 2. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $44.4{\pm}4.3%$, $109.5{\pm}12.3{\mu}m$ and $94.9{\pm}8.5{\mu}m$ in low doses of $17{\beta}-estradiol$ injected group and they showed statistical significance compare to OVX group. 3. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $44.4{\pm}4.3%$, $109.5{\pm}12.3{\mu}m$ and $94.9{\pm}8.5{\mu}m$ in medium doses of $17{\beta}-estradiol$ injected group and they showed statistical significance compare to OVX group, but they didn't show statistical significance compare to low doses of $17{\beta}-estradiol$ injected group. 4. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $46.4{\pm}4.5%$, $154.4{\pm}13.2{\mu}m$ and $113.7{\pm}12.8{\mu}m$ in high doses of $17{\beta}-estradiol$ injected group and they also showed statistical significance compare to OVX group, but they didn't show statistical significance compare to other experimental groups. From the above results, metaphyseal bone formation was markedly reduced in OVX rate but treatment of OVX rats with $17{\beta}-estradiol$ resulted in normalization of femur trabecular bone volume. But they didn't show statistical significance the effect of bone formation according to the dose dependency.

• Food Science and Biotechnology
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• 제17권3호
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• pp.553-557
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• 2008

The effects of cheonggukjang and doenjang on bone mineral density, trabecular area and cortical thickness of the tibia, and serum osteocalcin level in ovariectomized rats were investigated. After 4 weeks, bone mineral density, bone trabecular area, the cortical thickness index, and serum osteocalcin level were analyzed. The cheonggukjang and doenjang diet groups showed significant prevention of ovariectomized (OVX)-related body weight gain. Whole body bone mineral density of the OVX group was significantly lower than that of the sham group, whereas the cheonggulgang and doenjang diets resulted in complete restoration of bone mineral density. Trabecular area in the proximal diaphysis and cortical thickness in the distal diaphysis of the tibia were increased significantly in the cheonggukjang and doenjang diet fed groups. The cheonggukjang and doenjang diets significantly reduced serum osteocalcin level in the OVX rats. These results suggest that cheonggukjang and doenjang might have inhibitory effects on osteoporosis, by showing accelerated bone formation in OVX rats.

• 대한소아치과학회지
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• 제31권2호
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• pp.228-235
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• 2004

하악 과두의 발달과 증식은 측두하악관절 부위의 생역학적 환경의 변화에 따라 변경될 수 있다. 이 부위에 전달되는 생역학적 하중은 섭취하는 음식물의 경도를 다르게 함으로써 변화시킬 수 있다. 이번 연구의 목적은 성장 중인 쥐에서 부드러운 음식물의 섭취에 의해 저작력을 변화시키는 것이 하악 과두의 해면골의 형태를 변화시킬 수 있는지 미세전산화 단층촬영을 이용하여 분석하는 것이었다. 생후 21일 된 C57BL/6 쥐 36마리를 무작위로 두 그룹으로 나누었다. 8주 동안 대조군의 쥐들은 일반적인 딱딱한 덩어리의 사료를, 실험군의 쥐들은 덩어리의 사료를 잘게 갈은 후 물과 섞어 부드럽게 만들어 먹였다. 또한 실험군의 쥐들의 하악 절치를 일주일에 두 번씩 잘라서 짧게 만들었다. 8주 후 모든 쥐들을 희생하여 우측 하악 과두를 준비하였다. 미세전산화 단층촬영과 삼차원 영상 분석프로그램을 이용하여 하악 과두 해면골의 bone volume(BV), bone surface(BS), total volume(TV) bone volume fraction(BV/TV), surface to volume ratio(BS/BV), trabecular thickness(Tb. Th.), structure model index(SMI)와 degree of anisotropy(DA)를 측정하고 이들 값으로부터 trabecular number(Tb. N.)와 trabecular separation (Tb. Sp.)을 계산하였다 미세전산화 단층영상을 얻은 후 하악 과두의 조직 표본을 만들었다. 연구 결과는 다음과 같았다. 1. Bone volume fraction(BV/TV), trabecular thickness(Tb. Th.)와 trabecular number(Tb. N.)가 대조군에 비해 부드러운 음식을 먹인 실험군에서 유의하게 감소되었다(p<0.05). 2. Trabecular separation(Tb. Sp.)은 부드러운 음식을 먹인 실험군에서 유의하게 증가하였다(p<0.05). 3. Surface to volume ratio(BS/BV), structure model index(SMI), degree of anisotropy (DA)는 두 군 사이에 유의한 차이를 보이지 않았다(p>0.05). 4. 조직 절편을 관찰한 결과, 부드러운 사료를 먹인 실험군에서 하악 과두의 연골층의 증식 층과 전체 두께가 상당히 감소하였다.

• Imaging Science in Dentistry
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• 제43권4호
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• pp.227-233
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• 2013

Purpose: This study was performed to analyze human maxillary and mandibular trabecular bone using the data acquired from micro-computed tomography (micro-CT), and to characterize the site-specific microstructures of trabeculae. Materials and Methods: Sixty-nine cylindrical bone specimens were prepared from the mandible and maxilla. They were divided into 5 groups by region: the anterior maxilla, posterior maxilla, anterior mandible, posterior mandible, and mandibular condyle. After the specimens were scanned using a micro-CT system, three-dimensional microstructural parameters such as the percent bone volume, bone specific surface, trabecular thickness, trabecular separation, trabecular number, structure model index, and degrees of anisotropy were analyzed. Results: Among the regions other than the condylar area, the anterior mandibular region showed the highest trabecular thickness and the lowest value for the bone specific surface. On the other hand, the posterior maxilla region showed the lowest trabecular thickness and the highest value for the bone specific surface. The degree of anisotropy was lowest at the anterior mandible. The condyle showed thinner trabeculae with a more anisotropic arrangement than the other mandibular regions. Conclusion: There were microstructural differences between the regions of the maxilla and mandible. These results suggested that different mechanisms of external force might exist at each site.

• 운동영양학회지
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• 제24권1호
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• pp.1-8
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• 2020

[Purpose] This study compared differences in trabecular bone architecture and strength caused by jump and running exercises in rats. [Methods] Ten-week-old male Wistar rats (n=45) were randomly assigned to three body weight-matched groups: a sedentary control group (CON, n=15); a treadmill running group (RUN, n=15); and a jump exercise group (JUM, n=15). Treadmill running was performed at 25 m/min without inclination, 1 h/day, 5 days/week for 8 weeks. The jump exercise protocol comprised 10 jumps/day, 5 days/week for 8 weeks, with a jump height of 40 cm. We used microcomputed tomography to assess microarchitecture, mineralization density, and fracture load as predicted by finite element analysis (FEA) at the distal femoral metaphysis. [Results] Both jump and running exercises produced significantly higher trabecular bone mass, thickness, number, and fracture load compared to the sedentary control group. The jump and running exercises, however, showed different results in terms of the structural characteristics of trabecular bone. Jump exercises enhanced trabecular bone mass by thickening the trabeculae, while running exercises did so by increasing the trabecular number. FEA-estimated fracture load did not differ significantly between the exercise groups. [Conclusion] This study elucidated the differential effects of jump and running exercise on trabecular bone architecture in rats. The different structural changes in the trabecular bone, however, had no significant impact on trabecular bone strength.

• 대한의용생체공학회:의공학회지
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• 제26권5호
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• pp.295-300
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• 2005

We introduce an x-ray micro tomography system capable of high resolution imaging of a local region inside a small animal. By combining two kinds of projection data, one from a full field-of-view (FOV) scan of the whole body and the other from a limited FOV scan of the region of interest, we have obtained zoomed-in images of the region of interest without any contrast a nomalies. We have integrated a micro tomography system using a micro-focus x-ray source, a $1248\times1248$ flat-panel x-ray detector, and a precision scan mechanism. Using the cross-sectional images taken with the zoom-in micro tomography system, we measured trabecular thicknesses of femur bones in postmortem rats. To compensate the limited spatial resolution in the zoom-in micro tomography images, we used the fuzzy distance transform for the calculation of the trabecular thickness. To validate the trabecular thickness measurement with the zoom-in micro tomography images, we compared the measurement results with the ones obtained from the conventional micro tomography images of the extracted bone samples.

• 한국음향학회지
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• 제32권2호
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• pp.181-189
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• 2013

본 연구의 목적은 생체 외 조건의 소 대퇴골에서 피질골이 해면질골의 음속(SOS) 및 광대역 초음파 감쇠(nBUA)와 같은 음향특성에 미치는 효과를 조사하는 것이다. 이를 위해 2개의 소 대퇴골을 이용하여 근위부로부터 12개의 해면질골 샘플 및 1.00, 1.47, 및 2.00 mm의 두께를 갖는 3개의 피질골 판을 제작하였다. 또한 해면질골 샘플에 피질골 판 부착 전후 측정된 음향특성과 해면질골 겉보기 골밀도 사이의 상관관계를 조사하였다. 해면질골 샘플의 초음파 입사면에 부착된 피질골 판의 두께가 증가함에 따라 SOS는 선형적으로 증가하는 반면에 nBUA는 피질골 판의 두께에 대해 비선형적인 의존성을 나타내는 것을 알 수 있었다. 또한 서로 다른 두께를 갖는 피질골 판이 부착되더라도 SOS(r = 0.95-0.97) 및 nBUA(r = 0.53-0.73)와 해면질골 겉보기 골밀도 사이의 높은 상관관계는 유지되는 것을 알 수 있었다. 이와 같은 결과는 생체 외 조건의 피질골이 제거되지 않은 대퇴골에서 측정된 음향특성이 해면질골의 골밀도를 예측하기에 충분한 지표라는 것을 의미한다.

• Journal of Periodontal and Implant Science
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• 제47권1호
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• pp.20-29
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• 2017

Purpose: The microstructural characteristics of trabecular bone were identified using micro-computed tomography (micro-CT), in order to develop a potential strategy for implant surface improvement to facilitate osseointegration. Methods: Alveolar bone specimens from the cadavers of 30 humans were scanned by high-resolution micro-CT and reconstructed. Volumes of interest chosen within the jaw were classified according to Hounsfield units into 4 bone quality categories. Several structural parameters were measured and statistically analyzed. Results: Alveolar bone specimens with D1 bone quality had significantly higher values for all structural parameters than the other bone quality categories, except for trabecular thickness (Tb.Th). The percentage of bone volume, trabecular separation (Tb.Sp), and trabecular number (Tb.N) varied significantly among bone quality categories. Tb.Sp varied markedly across the bone quality categories (D1: $0.59{\pm}0.22mm$, D4: $1.20{\pm}0.48mm$), whereas Tb.Th had similar values (D1: $0.30{\pm}0.08mm$, D4: $0.22{\pm}0.05mm$). Conclusions: Bone quality depended on Tb.Sp and number-that is, endosteal space architecture-rather than bone surface and Tb.Th. Regardless of bone quality, Tb.Th showed little variation. These factors should be taken into account when developing individualized implant surface topographies.

• 전기학회논문지
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• 제59권4호
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• pp.823-830
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• 2010

This study was designed to examine the morphological measurement and characteristics of trabecullae based on femoral radiographic image for prediction of osteoporosis. Study subjects were 34 females (average age of 62.1 years) and 6 males (average age of 60.1 years), they were categorized into normal group and osteoporosis group in accordance with the T-score value. Measurement of the bone density of femoral bone was measured with DEXA(Dual Energy X-ray absorptiometry). ROI(Region of interests) was selected on femoral neck and trochanter. Characteristics of trabecullae was analyzed by using the skeletonization analysis of trabecular image. Morphological measurement was analyzed through femoral radiographic image in order to examine the correlation with osteoporosis. The result demonstrated statistically significant correlation between neck cortical thickness, shaft width, shaft cortical thickness, periphery, mean gray level and trabeculae area with BMD average (T-score) of femoral part. The results show that morphological measurement and characteristics of trabecullae based on femoral radiographic images for osteoporosis prediction could be effective.

• Imaging Science in Dentistry
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• 제52권4호
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• pp.375-382
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• 2022

Purpose: The aim of this study was to analyze the relationships between bone density measurements obtained using cone-beam computed tomography (CBCT) and morphometric parameters of bone determined by histomorphometric analysis. Materials and Methods: In this in vivo study, 30 samples from the maxillary bones of 7 sheep were acquired using a trephine. The bone samples were returned to their original sites, and the sheep heads were imaged using CBCT. On the CBCT images, gray values were calculated. In the histomorphometric analysis, the total bone volume, the trabecular bone volume (referred to simply as bone volume), and the trabecular thickness were assessed. Results: Statistical testing showed significant correlations between CBCT gray values and total bone volume (r =0.537, P =0.002), bone volume (r =0.672, P<0.001), and trabecular thickness (r =0.692, P<0.001), as determined via the histomorphometric analysis. Conclusion: The results indicate a significant and acceptable association between CBCT gray values and bone volume, suggesting that CBCT may be used in bone densitometry.