• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.777-785
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• 2001

치주질환이 진행되는 동안이나 치주처치후 치유되는 과정에서 치조골의 변화가 야기되는데 방사선 사진은 치조골 변화를 감지하는 유일한 비외과적인 방법이다. 미묘한 치조골 변화의 진단은 치료시나 유지관리기 환자의 평가시 중요한 바, 최근에는 규격화시킨 디지털 영상을 이용하여 정량적인 골변화 측정이 가능하게 되었다. 본 연구의 목적은 중등도의 치주질환을 지닌 환자에서 국소마취하에 초기 치주처치를 시행한후 참조체와 함께 구내 방사선 사진을 촬영하고 디지털화 한 다음 참조체 당량치를 이용하여 치조골의 밀도변화를 평가하기 위한 것이다. 이 연구를 위하여 치주질환에 이환된 환자 5명(남자 3명, 여자 2명 : 평균 47.4세)에서 탐침깊이가 5㎜ 이상이고 골내낭이 있는 제 $1{\cdot}2$ 소구치, 제 $1{\cdot}2$ 대구치 40개(상악 24개, 하악 16개)를 대상으로 구강위생교육과 치석제거술, 치근면활택술을 시행하였다. 임상지수는 술전과 술후 8주째에 측정하였고, 방사선 사진은 술전, 술후 2주, 4주, 6주, 8주째에 촬영하였고, 구리 스텝웨지를 사용하여 규격화 하였다. 촬영된 영상은 NIH image program(U.S.A)에 의해 분석되어졌고 이들 자료를 통해 다음과 같은 결과를 얻었다. 1. 치조골의 밀도는 초기치료후 2주째 까지는 감소된 양상을 보이다가 4주 이후로는 점차적으로 증가하는 양상을 보였다. 2. 치조골의 밀도는 초기치료전과 비교시 초기치료수 6주째와 8주째에서 유의한 차이를 보였다.(p<0.01) 3. 상하악 간의 치조골 밀도는 유의한 차이를 보이지 않았다(p>0.05). 이상과 같은 결과를 통하여 볼때 초기 치주처치만으로도 치조골의 밀도가 증가됨을 확인할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.369-372
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• 2012

대사성 골 질환인 골다공증(Osteoporosis)의 조기 진단을 위한 골 밀도를 측정하는 방법이 최근 연구되고 있다. 골 밀도 영상은 이중 에너지 X 선 흡수법에 의해 측정되는데, 영상에 존재하는 잡음은 뼈 영역 추출과 골 밀도 계산에 어려움을 주고 있다. 따라서 본 논문에서는 최근 신호처리 분야에서 폭넓게 사용되고 있는 sparse 표현을 도입하여 X 선 영상의 잡음을 제거하는 방법을 제안한다. 실험을 통해 제안한 잡음 제거 방법의 결과가 기존의 방법에 비해 개선됨을 MSR(Mean to Standard deviation Ratio)과 CNR(Contrast to Noise Ratio)을 통해 확인하였다.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.109-123
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• 2009

The aim of the study was to assess the influence of insertion torque of bone quality and to compare axial force, moment and von Mises stress using finite element analysis of plastoelastic property for bone stress and strain by dividing bone quality to its thickness of cortical bone, density of trabecular bone and existence of lower cortical bone when implant inserted to mandibular premolar region. The $Br{\aa}nemark$ MKIII. RP implant and cylindrical bone finite model were designed as cortical bone at upper border and trabecular bone below the cortical bone. 7 models were made according to thickness of cortical bone, density of trabecular bone and bicortical anchorage and von Mises stress, axial force and moment were compared by running time. Dividing the insertion time, it seemed 300msec that inferior border of implant flange impinged the upper border of bone, 550msec that implant flange placed in middle of upper border and 800msec that superior border of implant flange was at the same level as bone surface. The maximum axial force peak was at about 500msec, and maximum moment peak was at about 800msec. The correlation of von Mises stress distribution was seen at both peak level. The following findings were appeared by the study which compared the axial force by its each area. The axial force was measured highest when $Br{\aa}nemark$ MKIII implant flange inserts the cortical bone. And maximal moment was measured highest after axial force suddenly decreased when the flange impinged at upper border and the concentration of von Mises stress distribution was at the same site. When implant was placed, the axial force and moment was measured high as the cortical bone got thicker and the force concentrated at the cortical bone site. The influence of density in trabecular bone to axial force was less when cortical bone was 1.5 mm thick but it might be more affected when the thickness was 0.5 mm. The total axial force with bicortical anchorage, was similar when upper border thickness was the same. But at the lower border the axial force of bicortical model was higher than that of monocortical model. Within the limitation of this FEA study, the insertion torque was most affected by the thickness of cortical bone when it was placed the $Br{\aa}nemark$ MKIII implant in premolar region of mandible.

• Bulletin of Food Technology
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• v.15 no.1
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• pp.16-26
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• 2002

이 논문은 대두 이소플라본 섭취가 난소를 절제한 쥐의 골격 손실에 미치는 영향을 투여량에 따라 조사한 것이다. 실험 초기에 암컷의 Wistar rats(7개월령; n=55)을 절제 후 봉합시킨 군(SH; n=14)과 난소절제군(OVX; n=41)으로 각각 구분하여 사육하고 80일 후에 각 5마리씩을 해부하여 난소절제로 인한 골손실 진행여부를 확인하였다. 그 후 난소절제 쥐(OVX)를 9마리씩 4그룹으로 나누고 대두 이소플라본(IF, 대두단백질이 없는 실험식이에 혼합하여 공급)을 각각 0, 20, 40, 80mg/ (kg body.d)씩 84일간 공급하였다. 동시에 SH rats에게도 이소플라본이 없는 실험식이를 섭취시켰으며 164일 후에 해부하였다. 예상했던 대로 골 무기질 밀도(대퇴골, 골간부위와 골간단부위) 및 골 표면적에 대한 다공성 골 면적의 비(대퇴골 원위부 골간단에서)가 OVX군이 SH군보다 낮았다(P<0.05). OVX군은 SH군보다 혈장 osteocalcine 농도가 높았으며 소변으로의 deoxypyridinoline 배설량이 많았다(P<0.05). 164일째 osteocalcine 과 deoxypyridinoline 농도는 OVX군에서보다 IF40 및 IF80군에서 더 낮았다(P<0.05). 그럼에도 불구하고 골 무기질 밀도와 다공성 골 면적이 OVX군에서보다 IF군들에서 더 낮아지지는 않았다. 그러므로 난소를 절제한 성숙한 쥐에게 대두 이소플라본을 매일 섭취시키는 것은 골격조직의 재흡수를 감소시킬 수 있으나 이미 진행된 골감소증(osteophenia)을 회복시킬 수는 없는 것으로 나타났다.

• Food Engineering Progress
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• v.14 no.2
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• pp.106-111
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• 2010

In this study, we performed corrugation fluting experiments to examine the relationship between high-low corrugation of a corrugated medium and compressive strength of corrugated containers for food packaging. A low-grade corrugated medium was found to suffer from weak tensile resistance and to be prone to stealing, which tends to produce low corrugation. In contrast, a medium with a large corrugation deviation often caused slimming during fluting and produced irregular corrugations. Experiments of high-low corrugation distribution according to corrugated medium grades indicate that a high grade medium shows a smaller ratio of low corrugation. The thickness of corrugated fiberboard is weakly correlated to the basis weight of medium, yet positively correlated to the medium thickness (y=3.9732x+4.2712, $R^{2}=0.8142$) and inversely proportional to the medium density (y=-3.1213x+6.8736, $R^{2}=0.9919$). Compressive strength of a corrugated fiberboard box is low, if made of corrugated medium with large low corrugation distribution. Compressive strength showed 13% variation with respect to medium grades and 21% variation for various test samples. The corrugation fluting of a corrugated medium is related to physical properties such as basis thickness and density.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.29-40
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• 2011

The purpose of this study was to examine the association among bone mineral density (BMD), biochemical bone markers, nutrients, and salt intake in premenopausal and postmenopausal women. We evaluated 431 subjects who visited a health promotion center of a university hospital between January 2008 and July 2009. We excluded those who were taking medications or who had an endocrine disorder affecting osteoporosis. The subjects were divided into premenopausal (n = 283) and postmenopausal (n = 143) women. We evaluated the correlation among BMD of the lumbar spine, femoral neck, and total femoral, as well as biochemical bone markers, hormone, serum profiles, general characteristics, nutrient intakes, and food intake frequencies. From a stepwise multiple regression analysis, lumbar spine BMD was positively correlated with weight (p < 0.001) and negatively correlated with osteocalcin (OC)(p < 0.001), Femoral neck BMD was positively correlated with weight (p < 0.001) and negatively correlated with C-telopeptide (CTx) and alkaline phosphatase (ALP)(p < 0.001, p < 0.05). In premenopausal women, femoral total BMD was positively correlated with BMI (p < 0.001) and negatively correlated with CTx (p < 0.001). In postmenopausal women, lumbar spine BMD was positively correlated with calcium intake (p < 0.01) and negatively correlated with sodium intake (p < 0.01). Femoral neck and femoral total BMD were both positively correlated with weight (p < 0.001), and femoral neck BMD was negatively correlated with age and ALP (p < 0.001, p < 0.05). Femoral total BMD was negatively correlated with age and OC (p < 0.001, p < 0.01). These results suggest that reducing sodium intake may play an important role delaying bone resorption and preventing a decrease in BMD.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.419-424
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• 2001

We intended to evaluate the Young's modulus of trabecular bone of a human distal femur by spherical Indentation test and CT images and to quantify relationships between the direction of load, density. and Young's modulus. The specimens were scanned at 1 mm intervals on CT scanner After scanning the bones were sectioned with diamond saw. producing 8mm cubes of trabecular bone. The tubes were mechanically tested in inferior-superior(IS), anterior-posterior(AP). and medial-lateral(ML) direction with custom-made device. After testing, the real apparent density of specimens were measured. The results of this study showed that the IS modulus was significant1y greater than both the AP and ML modulus and the AP modulus was also greater than ML modulus significantly(p〈0.01) A significant Power relationship between the apparent density and the modulus was also found.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.30-33
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• 2012

대사성 골 질환인 골다공증(Osteoporosis)의 조기 진단을 위해 X 선 영상에서 골 밀도를 측정하는 방법이 최근 연구되고 있다. 골 밀도는 X 선 영상에서 뼈가 분리되고, 분리된 영역에서의 픽셀에 의해 BMD가 측정되는데, 개선된 영상에서의 정밀한 뼈 추출이 주요한 요소이므로 X 선 영상의 개선은 골다공증의 조기 진단을 위해 필수적이다. 본 논문에서는 sparse 표현법을 도입하여 X 선 영상을 개선시키는 방법을 제안한다. 실험을 통해 제안한 방법의 결과가 기존의 방법인 웨이블릿 BayesShrink에 비해 개선됨을 CNR(Contrast to Noise Ratio)을 통해 확인하였다.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.233-238
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• 2014

Purpose: A method detecting change of jaw or alveolar bone density may be helpful in periodontal care, implant dentistry and evaluation of bone density of whole body. Materials and methods: In this study, bone density of intraoral periapical radiography using phantom-integrated XCP is compared with that of quantitative computed tomography (QCT). Results: Bone density of intraoral periapical radiography and the one measured by QCT showed high correlation (correlation coefficient = 0.92, P<.001) in alveolar bone, and relatively high correlation (0.73, P<.001) in cancellous bone. Conclusion: This study revealed possibility of scoring of bone density by intraoral periapical radiography.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.369-373
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• 2003

The compressed fracture of spine caused by osteoporosis is one of the most frequent diseases in bone fracture. Recently the vertebroplasty has drawn much attention as a medical treatment for the compressed fracture of spine, which strengthens the vertebral body and corrects deformity, and relieves pain in patients by injecting bone cement. But because there were no research about strengthening of mechanical properties of verbral body in bone cement injection, in this study, based on the properties of PMMA, we had measured the Young's modulus for different apparent densities of intact trabecular bone and PMMA injected one from a porcine and a cadaver. Young's modulus to apparent density had a form of a power series in intact trabecular bone and had a linear relation in PMMA injected bone.