• 동의생리병리학회지
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• 제20권5호
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• pp.1226-1232
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• 2006

This study was carried out to investigate the effects of Cervi Pontotrichum cornu and Carthami semen on the serum osteocalcin level, bone mineral density, bone trabecular area and cortical thickness index in ovariectomized rats. Femal Sprague-Dawley rats were divided into 5 groups. Non-ovariectomized groups were divided into commertial diet fed(normal group) and calcium free basal diet fed(sham operation group). Ovariectomized groups were divided into 3groups, calcium free basal diet fed group(control group or ovariectomized group), 10% Cervi Pontotrichum cornu supplemented diet fed group and 10% Carthami semen supplemented diet fed group. After 4 weeks diet fed, serum osteocalcin level, bone mineral density, bone trabecular areas and cortical thickness index were analyzed. The bone mineral density and bone trabeculae area were significantly increased by Cervi Pontotrichum cornu and Carthami semen supplemented diet fed groups. The osteocalcin level was significantly decreased by Cervi Pontotrichum cornu and Carthami semen supplemented diet fed groups. The trabecular area(%) in epiphysis of tibia was significantly increased by Cervi Pontotrichum cornu and Carthami semen supplemented diet fed groups. The cortical thickness index in distal diaphysis of tibia was significantly increased by Cervi Pontotrichum cornu and Carthami semen supplemented diet fed groups. the alkaline phosphatase level was significantly decreased by Cervi Pontotrichum cornu and Carthami semen supplemented diet fed groups. These results suggest that Cervi Pontotrichum cornu and Carthami semen might have inhibitory effects on osteoporosis by increasing bone mineral density and accerelating bone formation in ovariectomized rats.

• Animal cells and systems
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• 제16권5호
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• pp.357-365
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• 2012

We have examined the effect of circadian disturbances induced by night shifts (NSs) on the phenotypes of the tibiae and abdominal adipose tissues (ADTs) in a mouse model by using in vivo micro-computed tomography (micro-CT). We found that the volumes of total and visceral ADTs in the night-shifted group of mice were significantly larger (69 and 92%, respectively) than those in the control. The mean polar moment of inertia, cross-sectional thickness, and bone mineral density of the cortical bone in the night-shifted group of mice were less (13, 5, and 3%, respectively) than those in the control. Moreover, the volume and the thickness of growth plates (GPs) of the tibiae in the night-shifted mice were significantly smaller (22 and 20%, respectively) than those in the control. Taken together, our results indicate that disturbances in the mouse circadian rhythms induced by NSs affect the morphological characteristics of cortical bone, the volume and the thickness of GPs, and the volume of ADTs.

• 비파괴검사학회지
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• 제35권2호
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• pp.103-111
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• 2015

본 연구에서는 골절 위험도가 높은 대퇴골의 두꺼운 피질골판이 해면질골의 초음파 특성에 미치는 영향을 조사하였다. 이를 위해 소의 대퇴골을 이용하여 12개의 해면질골을 제작하였으며, 피질골과 유사한 밀도 및 음속을 갖는 아크릴을 이용하여 피질골판을 모사하는 1.25, 1.80, 및 2.75 mm의 두께를 갖는 아크릴판을 제작하였다. 해면질골 양면에 부착된 아크릴판의 두께가 증가하더라도 음속과 해면질골의 겉보기 골밀도 사이에 Pearson 상관계수는 0.80-0.86의 값을 가지며, 높은 상관관계가 존재하는 것으로 나타났다. 또한 0.5 MHz에서 측정된 감쇠계수와 해면질골의 겉보기 골밀도 사이에 Pearson 상관계수는 0.84-0.91의 값을 가지며, 높은 상관관계가 존재하는 것으로 나타났다. 이와 같은 결과로부터 종골에 비해 상대적으로 더 두꺼운 피질골판을 갖는 대퇴골에서 측정된 음속 및 특정 주파수에서의 감쇠계수는 대퇴골의 골밀도를 예측하기 위한 지표로서 이용될 수 있음을 알 수 있다.

• 치과방사선
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• 제29권1호
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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.

• 대한치과보철학회지
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• 제34권1호
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• pp.187-200
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• 1996

After loss of tooth, initial healing process is critical to preserve residual alveolar process. This study was conducted to compare the effect of hydroxylapatite particle synthetic graft and guided tissue regeneration procedure on healing of extraction wounds in 5 mongrel dogs. To investigate the maturity of bone and velocity of bone heating, bone-labeled tracers were used. After 16 weeks healing period, dogs were sacrificed. The specimens were treated with Villanueva bone stain. Fluorescence microscopy and polarized microscopy were performed to exam the pattern of bone formation in the extraction socket. The results were following ; 1. Pattern of bone regeneration in the group of hydroxylapatie graft and the group of membrane protection after hydroxylapatite graft was following ; bone regeneration was slow, regenerated bone was immature, and thickness of cortical layer was thin compare to that of untreated control group. 2. Cortical layers in membrane protected group were somewhat thicker but less condense to that of untreated control group. 3. Infiltration of inflammation cells were found in the groups using hydroxylapatite graft and membrane. We concluded that grafting of replamineform hydroxylapatite particles into the extraction socket delayed healing of the wound and disturbed the formation of cortical bone at the roof of extraction socket. The placement of expanded polytetrafluoroethylene membranes on the extraction socket promotes the bone regeneration. But newly formed bone in cortical layer consists of the cortico-cancellous bone in comparison with the cortical bone of the control group.

• 대한치과교정학회지
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• 제33권1호
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• pp.11-20
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• 2003

본 연구는 교정치료 시 고정원 보강을 위해 사용되는 교정용 미니스크류의 길이, 직경 및 피질골 두께에 따른 응력 분포 양상을 알아보기 위하여 시행되었다. 미니스크류의 길이와 직경 변화에 따른 응력 분포 양상을 관찰하기 위하여 식립되는 피질골의 두께를 1.0mm로 고정하고 미니스크류의 길이를 6.0mm, 8.0mm, 10.0mm, 12.0mm로, 직경을 1.2mm, 1.6mm, 2.0mm인 3차원 유한요소 모델을 제작하였다. 또한, 피질골의 두께 변화에 따른 응력 분포 양상을 관찰하기 위하여 미니 스크류의 길이를 8.0mm로 고정하고 직경은 1.2mm, 1.6mm, 2.0mm로, 피 질골의 두께는 1.0mm, 1.5mm, 2.0mm, 2.5mm인 3차원 유한요소 모델을 제작하였다. 각각의 유한요소 모델의 미니스크류 head중심에 200gm의 수평력을 가하여 응력 분포 양상과 크기를 3차원 유한요소 해석 프로그램인 ANSYS를 이용하여 비교한 결과 다음과 같은 결론을 얻었다. 1. 미니스크류 내부에서 나타나는 최대 응력값을 비교한 결과, 미니스크류의 직경이 1.2mm에서 2.0mm로 증가할수록 응력이 감소하였으며 같은 직경에서는 길이 증가에 상관없이 일정한 값을 유지하였다. 2. 피질골 및 해면골에 작용되는 최대 응력값을 비교한 결과, 미니스크류의 직경이 1.2mm에서 2.0mm로 증가할수록 응력이 감소하였으며 같은 직경에서는 길이 증가에 상관없이 일정한 값을 유지하였다. 3. 피질골 및 해면골에 작용되는 응력 분포를 관찰한 결과, 대부분의 응력이 피질골에서 흡수되었으며 ,해면골에 전달되는 응력값은 미미하였다. 4. 피질골 두께에 따른 최대 응력값을 비교한 결과, 같은 미니스크류의 직경에서는 피질골의 두께 증가에 상관없이 일정한 값을 유지하였다. 이상의 결과는 교정용 미니스크류의 유지에 길이보다는 직경이 더 크게 관여하는 것으로 나타나 미니스크류의 식립시 이에 대한 고려가 필요함을 시사하였다.

• International Journal of Oral Biology
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• 제32권4호
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• pp.143-151
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• 2007

This study was conducted to investigate the preventing effects of OPB (Rehmannia glutinosa Libosch and Eleutherococcus senticosus Max extracts) and combined OPB/Calcium therapy on bone loss in ovariectomized rats. Sixty Sprague Dawley rats of 12-week-old were divided into eight groups: OVX (ovariectomized), OPBL (OPB 50 mg/kg), OPBM (OPB100 mg/kg), OPBH (OPB 200 mg/kg), OPBL/CAL(OPBL+CAL), OPBM/CAL (OPBM+CAL), OPBH/CAL (OPBH+CAL) and CAL (Calcium citrate 88.33 mg/kg+1$\alpha$, 25-dihydroxy-vitamin $D_3$ 33.33 IU/kg). Bone mineral density (BMD), bone mineral content (BMC), bone strength indices and cortical thickness were analyzed by peripheral quantitative computerized tomography (pQCT). pQCT scanning showed that OVX induced a significant decrease in trabecular bone mineral density and bone mineral content in the proximal tibia $(-36.4\pm2.4%,\;-21.8\pm12.7%)$. These decreases were significantly prevented by the administration of OPBM and OPBM/CAL. Cortical BMD and BMC of tibia were slightly enhanced by OPB and OPB/CAL. However there was no significant difference between OVX and OPB, OPB/CAL treated group. Bone strength indices and cortical thickness were not significantly different. Our results suggest that OPB and combined OPB/Calcium therapy are effective in preventing the development of bone loss induced by ovariectomy in rats.

• 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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• 제34권2호
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• pp.69-74
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• 2004

Purpose : This study was conducted to compare the radiomorphometric indices of the mandible on panoramic radiographs among three groups of normal, osteopenia and osteoporosis and to determine whether panoramic indices have validity in predicting osteoporotic risk. Materials and Methods: Ninty-four postmenupausal women aged 42-72 years (mean 62±7.5) were examined using dual energy X-ray absorptionmetry (DEXA) of the lumbar and classified into three groups by WHO classification. Panoramic mandibular index (PMI), mandibular cortical thickness (Mental index (MI), Antegonial index (AI), Gonial index (G!)) and the mandibular cortical index (MCI) were measured bilaterally on panoramic radiographs and analyzed. Results: There were signigicant differences among normal, osteopenic and osteoporoti groups in PMI (I), PMI (S), MI, AI, GI and MCI. The sensitivities of the MCI (93%) and the combination index of MCI and MI (90%) in diagnosing osteopenic/osteoporotic cases were high. Conclusion: The widths and shapes of the mandibular cortical bone on panoramic radiography may highly reflect the systemic osteopenic/osteoporotic conditions of the patients.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.777-788
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• 2005

The primary stability of implants is an important factor to predict the osseointegration. Recently, the resonance frequency analysis has been used to measure the primary stability. It is an objective method to monitor the stability of implants during healing phase. This study is to validate the differences in the effect of the osteotome method according to the bone quality as well the thickness of cortical bone. Two hundred seventy implants of 3.75mm in diameter(Neoplant, Neobiotech, Korea) were placed in 135 bovine ribs. The bone quality is classified into 3 classes according to the number of bone marrow spaces which implants would be placed, and then classified into 9 subclasses after the ribs were trimmed. Two implants were placed in 15 specimens of each class. The conclusion were as follows: 1. In case of less dense cancellous bone, the oseotome method is more effective in primary stability rather than the drilling method(p <0.05). 2. If there was cortical bone, it is more advantagous to get stronger primary stability. 3. If cancellous bone is more dense or if cortical bone exists, there is no statistical significance between drilling and osteotome method(p <0.05).