• 대한족부족관절학회지
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• 제11권1호
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• pp.111-114
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• 2007

Open calcaneal fracture with more than lateral half of bone loss and soft tissue defect occurred in 17 year-old male patient due to motor vehicle accident. Soft tissue defect included heel pad, peroneal tendon. Bone loss involved mainly most part of inferior tuberosity but not subtalar joint. Open dressing and debridement were done daily in operating room and antibiotics administration was started. After granulation tissue formed, femoral head allograft was performed and fixed with 6.0 mm screws to replace bone defect. Soft tissue defect was covered with latissimus dorsi musculocutaneous free flap. No sign of infection nor major osteolysis was observed in 15 months follow up period. Soft tissue defect was covered with latissimus dorsi musculocutaneous free flap.

• 대한치과의사협회지
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• 제45권9호통권460호
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• pp.562-570
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• 2007

Many dentists and patients expect that implant function and esthetics will not change over time. However, even the most successful implant restorations with ideal position, vertical height, and occlusion can be aesthetically pleasing, but may hide a common problem. Many dentists noticed that there can be some circumferential bone loss around the neck of the implants. To circumvent this bone loss, a "platform switching" concept was introduced recently. The basic concept of platform switching is by moving the fixture-abutment interface further away from the crestal bone to minimize crestal bone loss. Since crestal bone loss is a multifactor problem, it is important to consider microgap formation and micromotion between the implant and abutment because platform switching does not solve the problem on its own. In this article, we reviewed studies concerning platform switching and discussed the clinical application and the problems that may occur with its use.

• 한국산학기술학회논문지
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• 제15권6호
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• pp.3781-3788
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• 2014

국민건강영양조사 제 5기 1 2차년도에 참여한 남성을 대상으로 연령에 따른 부위별 골밀도 변화, 골 소실률에 대해서 알아보고자 시도 하였다. 연령에 따른 골밀도 변화를 가장 잘 보여 주기 위해 Cubic regression을 사용하였고, 척추, 대퇴경부, 대퇴골 전자부, Ward 부위 골밀도 차이는 분산분석을 이용하여 분석하였다. 연구결과, 요추, 대퇴골 전체, 대퇴경부, 대퇴골 전자부, Ward 부위의 최대 골밀도는 20-24세였으며, 75-79세에서 골 소실률이 가장 높았다. 따라서, 남성에서는 75세 이상에서 골다공증의 집중적인 관리가 필요할 것이며, 남성에서의 골다공증 진단기준은 국제 임상 골밀도 학회(The International Society for Clinical Densitometry; ISCD)의 지침을 따르는 방안을 고려해 봐야 할 것이다.

• BMB Reports
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• 제53권3호
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• pp.154-159
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• 2020

We investigated the effects of physalin A, B, D, and F on osteoclastogenesis induced by receptor activator of nuclear factor κB ligand (RANKL). The biological functions of different physalins were first predicted using an in silico bioinformatic tool (BATMAN-TCM). Afterwards, we tested cell viability and cell apoptosis rate to analyze the cytotoxicity of different physalins. We analyzed the inhibitory effects of physalins on RANKL-induced osteoclastogenesis from mouse bone-marrow macrophages (BMMs) using a tartrate-resistant acid phosphatase (TRAP) stain. We found that physalin D has the best selectivity index (SI) among all analyzed physalins. We then confirmed the inhibitory effects of physalin D on osteoclast maturation and function by immunostaining of F-actin and a pit-formation assay. On the molecular level, physalin D attenuated RANKL-evoked intracellular calcium ([Ca(2+)](i)) oscillation by inhibiting phosphorylation of phospholipase Cγ2 (PLCγ2) and thus blocked the downstream activation of Ca2+/calmodulin-dependent protein kinases (CaMK)IV and cAMP-responsive element-binding protein (CREB). An animal study showed that physalin D treatment rescues bone microarchitecture, prevents bone loss, and restores bone strength in a model of rapid bone loss induced by soluble RANKL. Taken together, these results suggest that physalin D inhibits RANKL-induced osteoclastogenesis and bone loss via suppressing the PLCγ2-CaMK-CREB pathway.

• Journal of Radiation Protection and Research
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• 제41권3호
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• pp.253-259
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• 2016

Background: This study investigated the effects of zoledronic acid (ZA) on radiation-induced bone loss in C3H/HeN mice. Materials and Methods: C3H/HeN mice were divided into sham control and three irradiated groups (3 Gy, gamma ray). The irradiated mice were treated for 12 weeks with vehicle, amifostine (intraperitoneal injection), or ZA (subcutaneous injection). Grip strength, uterus weight, and serum alkaline phosphatase (ALP), and tartrate-resistant acid phosphatase (TRAP) levels were measured. Tibiae were analyzed using micro-computed tomography. Results and Discussion: Treatment of ZA ($100{\mu}g{\cdot}kg^{-1}{\cdot}week^{-1}$) significantly preserved trabecular bone volume, trabecular thickness, trabecular number, trabecular separation, bone mineral density of proximal tibia metaphysic, and cortical bone volume, but did not alter the uterus weight of the mice. The administration of ZA for 12 weeks lowered serum ALP and TRAP levels in irradiated mice, suggesting that ZA can reduce the bone turnover rate in mice. No differences were apparent between the amifostine-treated group and the irradiation control group. Conclusion: The results indicate that ZA can prevent radiation-induced bone loss in mice.

• Journal of Ginseng Research
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• 제37권4호
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• pp.435-441
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• 2013

This study investigated the effects of Korean Red Ginseng (KRG) on radiation-induced bone loss in C3H/HeN mice. C3H/HeN mice were divided into sham and irradiation (3 Gy, gamma-ray) groups. The irradiated mice were treated for 12 wk with vehicle, KRG (per os, p.o.) or KRG (intraperitoneal). Serum alkaline phosphatase (ALP), tartrate-resistant acid phosphatase, estradiol level, and biomechanical properties were measured. Tibiae were analyzed using micro-computed tomography. Treatment of KRG (p.o., 250 mg/kg of body weight/d) significantly preserved trabecular bone volume, trabecular number, structure model index, and bone mineral density of proximal tibia metaphysic, but did not alter the uterus weight of the mice. Serum ALP level was slightly reduced by KRG treatment. However, grip strength, mechanical property, and cortical bone architecture did not differ among the experimental groups. The results indicate that KRG can prevent radiation-induced bone loss in mice.

• 대한치과보철학회지
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• 제35권4호
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• pp.674-696
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• 1997

There're many cases that should be reconstructed with post and core when clinical crown is destructed. But this post and core restoration may cause damaging stress on the teeth. Previous finite element study was restricted to normal bone model relatively close to cemen-toenamel junction. Moreover, the test of a model with diminished bone support was rare. The purpose of this study is to test the effects of alveolar bone loss on the magnitude, stress distribution and displacement of post reconstructed teeth. In this study, it was assumed that the coronal portion of upper incisor was severely destructed. After conventional endodontic treatment, it was restored with post and core. The PFM restoration was made on it. This crown was cemented with ZPC. Alveolar bone was classified by 4 types of bone, such as normal, 2 mm, 4 mm, 6 mm bone, according to the bone loss. Meanwhile, the material of post are divided into 2 types of materials, such as gold, co-cr. Force was applied to two directions. One was fuctional maximum bite force (300 N) applied to the spot just lingual to the incisal edge with the angle of 45 degree to the long axis of the tooth, and the other one was horizontal force (300 N) applied to the labial surface. The results analyzed with three dimensional finite element method were as follows : 1. Stress was concentrated on the adjacent dentin of the post apex, one third portion of the post apex and the labial & lingual mid-portion of the root in all case. The stress of middle third of the root was apparently concentrated on the labial aspect. 2. The stress on adjacent dentin of the post apex and one third of the post apex increased as alveolar bone height moved apically. This increase was dramatic beyond 4 mm bone loss model. 3. The stress of the post apex was spreaded to the middle third of the post and greater than gold post in the case of metal post. 4. The displacement of the neck of post was the greatest in one of the post-cement interface and this increased as alveolar bone height moved apically. Besides the displacement of the metal post is slightly lower than one of the gold post.

• 한국전문물리치료학회지
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• 제8권1호
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• pp.51-58
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• 2001

In children with cerebral palsy, bone density is decreased by disturbance of bone remodelling due to lack of normal weight bearing and muscle contraction through physical activity. Loss of bone density cause fracture, delays treatment with immobilization, and leads to functional limitation. The purpose of this study was to investigate bone mineral density of lumbar spine in children with spastic quadriplegia and diplegia. Six spastic quadriplegia and 14 spastic diplegia were evaluated in this study. QDR 4500 X-ray densitometer was used to measure bone density at lumbar spine (L1~L4). Children with cerebral palsy showed lower bone density than that of normal children. Bone density in children with spastic quadriplegia and diplegia was $-1.812{\pm}.962$, $-1.519{\pm}.935$, respectively. However, there was no significant differences in bone density between children with spastic quadriplegia and diplegia. There was no significant difference in bone density relation to motor development level, height, and weight. Further study is needed to find the appropriate interventions for preventing loss of bone density in children with cerebral palsy.

• Toxicological Research
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• 제22권3호
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• pp.253-266
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• 2006

Bone is a dynamic tissue that is constantly being remodelled. Resolution of bone and formation of new bone are closely linked, so that bone mass remains constant. With age, this process becomes unlinked with an imbalance in bore resorption and formation that results in a net loss of bone. Especially, osteoporosis is a disease characterized by low bone mass with age. One form of aging-related primary osteoporosis is postulated with the reduction of circulating estrogen, rapid bone loss occurs as a result of enhanced bore remodelling with an excess of resorption over bore formation. The oxidative stress is also involved in the pathogenesis of osteoporosis. Oxidative stress by cytokines, such as IL-a and TNF-${\alpha}$, inhibits osteoblast function in vitro and stimulates osteoblast apoptosis resulting in an imbalance in bore remodelling. The present article reviews the current perspectives on the interaction between bone remodelling and factors such as estrogen and oxidative stress, providing an interpretation of bone diseases in a view of molecular mechanisms.

• Advances in biomechanics and applications
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• 제1권3호
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• pp.211-225
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• 2014

The usual assumption that the increase of fractures in aging bone is due entirely to lower bone density is taken back with respect to the possibility that aging bone fractures result from a loss of stability, or buckling, in the structure of the bone lattice. Buckling is an instability mode that becomes likely in end-loaded structures when they become too slender and lose lateral support. The relative importance of bone density and architecture in etiology bone fractures are poorly understood and the need for improved mechanistic understanding of bone failure is at the core of important clinical problems such as osteoporosis, as well as basic biological issues such as bone formation and adaptation. These observations motivated the present work in which simplified adaptive-beam buckling model is formulated within the context of the adaptive elasticity (Cowin and Hegedus 1976, Hegedus and Cowin 1976). Our results indicate that bone loss activation process leads systematically to the apparition of new elastic instabilities that can conduct to bone-buckling mechanism of fracture.