• International Journal of Oral Biology
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• 제30권4호
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• pp.143-148
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• 2005

Osteoclasts are multinucleated cells with bone resorbing activity and differentiated from hematopoietic cell lineages of monocyte/macrophages in the presence of receptor activator of NF-${\kappa}B$ ligand (RANKL) and M-CSF. However, the exact molecular mechanisms through which RANKL stimulates osteoclastogenesis remain to be elucidated. Here we report that activation of cAMP-response elementbinding protein (CREB) is not involved in osteoclastogenesis from osteoclast precursors in response to RANKL. RANKL induced CREB activation in osteoclast precursors. Using pharmacological inhibitors, we found that RANKL-induced CREB activation is dependent on p38 MAPK pathways. We also found that ectopic expressions of wild type and dominant negative forms of CREB in osteoclast precursors did not affect RANKL-induced osteoclast formation and bone resorbing activity. Furthermore, dominant negative forms of CREB did not alter the expression levels of osteoclast-specific marker genes. Taken together, these data suggest that CREB is dispensable for differentiation and resorbing activity of osteoclasts.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.389-402
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• 2002

BMP can induce ectopic bone formation when implanted into sites such as rat muscle and can greatly enhance healing of bony defects when applied exogenously. In addition, BMP stimulated osteoblastic differentiation in vitro in various types of cells. The aim of this study was to investigate the effect of recombinant human bone morphogenetic protein(rhBMP-2) on the proliferation and osteoblastic differentiation of human periodontal ligament cells and gingival fibroblasts. The cell number and alkaline phosphatase activity were measured in 3 experimental groups of human periodontal ligament cells and gingival fibroblasts (control group, rhBMP-2 50ng/ml group, and rhBMP-2 100ng/ml group) at 1 and 2 weeks after culture. At the same time, total RNA of cultured cells were extracted and reverse trascription polymerase chain reaction(RT-PCR) was performed to determine the expression of mRNA of bone matrix protein. RhBMP-2 had no effect on the cell proliferation of human periodontal ligament cells and gingival fibroblasts. Alkaline phosphatase activity was elevated significantly by rhBMP-2 in both cells. And periodontal ligament cells showed significantly higher alkaline phosphatase activity than gingival fibroblasts. ${\beta}$-actin, type I collagen, alkaline phosphatase, BMP-2 mRNA were expressed in all of the samples. Osteopontin, osteocalcin mRNA were expressed in all periodontal ligament cell groups, and rhBMP-2 50ng/ml group, rhBMP-2 100ng/ml group of 2 week culture period of gingival fibroblasts. Bone sialoprotein mRNA was only expressed in rhBMP-2 50ng/ml group and rhBMP-2 100ng/ml group of 2-week culture period. These results suggest that rhBMP-2 stimulates osteoblastic differentiation in human periodontal ligament cells and gingival fibroblasts in vitro.

• 동의생리병리학회지
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• 제26권3호
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• pp.320-324
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• 2012

Osteoporosis is an important public health issue in postmenopausal women. It is a major public health concern and is widely believed that osteoporosis results from imbalance between bone resorption and bone formation. Recently natural products from plants have been extensively studied as therapeutic drugs to treat and prevent various diseases. Hoelen (scientific name, Poria cocos) is a mushroom that is used in traditional Chinese medicine. Hoelen exhibits anti-inflammatory activity and has a protective effect on tumor progression. However, the effect of hoelen in osteoclast differentiation remains unknown. Thus, we examined the effect of hoelen in receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. Hoelen significantly inhibited RANKL-induced osteoclast differentiation in bone marrow-derived macrophages (BMMs) in dose dependent manner without toxicity. Also, we showed that hoelen significantly inhibited the mRNA expression of tartrate-resistant acid phophatase (TRAP) and nuclear factor of activated T cells 1 (NFATc1) in BMMs treated with RANKL. In Particular, hoelen greatly inhibited the protein expression of NFATc1. Ectopic expression of NFATc1 partially reverses hoelen-mediated inhibition of osteoclast differentiation. Taken together, our results demonstrated that hoelen may be useful treatment option of bone-related disease such as osteoporosis, reumatoid arthritis, and periodontitis.

• Journal of Periodontal and Implant Science
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• 제31권1호
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• pp.21-41
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• 2001

The goal of Periodontal treatment is predictable periodontal regeneration. But until now, many products including GTR materials and growth factors are beyond of complete regeneration. BMP can induce ectopic bone formation when implanted into sites such as rat muscle and can greatly enhance healing of bony defects when applied exogenously. BMP can promote periodontal regeneration by their ability to stimulate new bone and new cementum formation. But little is known about optimal conditions required for the application. Root conditioning is used for bioacive root change so altered root surface provides a substrate that promotes chemotaxis, migration and attachment of peridontal cells encouraging connective attachment to the denuded root surface. The aim of this study is to investigate whether the acid conditioning change effect of rhBMP-2 on human periodontal ligament cell and osteoblast cell line. 288 periodontally involved root dentin slices are divided into 6 groups, each 48, 1)control, 2)treated with BMP, 3)treated with citric acid 4)treated with citric acid+BMP 5)treated with tetracycline 6)treated with TC+BMP. Each group was devided half, so 12 root dentin slices were seeded with periodontal ligament cells and 12 were seeded with osteoblasts. At day 2 and 7, cell number, protein assay, ALP activitiy was measured. To investigate morphology of cultured cells, SEM was employed. Statistical analysis was performed with SPSS 8.0 either t-test or ANOVA test. The results are ; Protein assay and cell number was slightly decreased in CA+BMP group compared to Ca group but it was not statistically significant and ALP activity was much more increased in CA+BMP group compared to CA group so there was no statistically significance between BMP and CA+BMP group and statistically significant compared to control group. Cell number and protein assay was slightly increased in TC group and ALP activity was much less the BMP group and CA group. Cell number and protein and ALP activity was not much increased in TC+BMP group. TC group and TC+BMP group showed cell morphology change in SEM. This results suggested that application of root surface with citric acid before BMP treatment might give better result in periodontal regeneration.

• 대한소아치과학회지
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• 제28권2호
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• pp.255-260
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• 2001

유치의 외상으로 인해 이환된 유치의 손상뿐만 아니라 형성 중인 계승 영구치의 발육과 맹출에도 영향을 줄 수 있다. 가장 흔한 합병증으로는 법랑질의 변색이나 법랑질 저형성증이며, 드물게 계승 영구치의 매복, 이소성 맹출, 치관 또는 치근 만곡, 치근 형성 정지를 유발할 수도 있다. 본 증례들에서는 유치열에 대한 외상성 손상으로 계승 영구치가 심각한 발육 및 맹출 장애를 보였다. 증례 1에서는 4세 7개월경의 외상으로 인해 상악 우측 유중절치와 상악 우측 유측절치가 측방 탈구되고 증례 2에서는 3세경의 외상으로 상악 우측 유중절치와 유측절치가 완전 탈구되었다. 그 결과 계승 영구치인 상악 우측 중절치와 측절치가 모두 동시에 매복되고 치근형성이 정지되었으며 이소성 맹출이 관찰되었다. 계승 영구치의 발육 장애를 조기에 진단하고 치료하기 위해서는 정기적인 임상 및 방사선학적 검사가 필요하다.

• 대한소아치과학회지
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• 제25권1호
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• pp.127-133
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• 1998

An impacted tooth is defined pathologically as a tooth that remains under the mucosa of inside bone without eruption of the crown after a specific period of eruption. Clinically, the term includes those teeth, even before eruption period, that are not expected to erupt due to shape, position and alignment of tooth and lack of space. Canine is prone to impaction more than other teeth because it has the longest time to develop and a complex route from the place of formation to the site of eruption. The impaction incidence of maxillary canine is repoted 0.92$\sim$3.3% (Ferguson, 1990). In 1995 Orton reported that the incidence was 0.92$\sim$2.2% and palatal impaction was more frequent than labial impaction(85%:15%). In 1969 Johnston presented it was more common to woman than to man(3:1). The etiology includes systemic disease such as endocrine disorder, cleidocranial dysostosis, irradiation, Crouzon syndrome, ricketts, facial hemihypertrophy and hereditary and local problems such as ectopic position of the tooth, distance of tooth from its place of eruption, malformation of the tooth, presence of supernumerary teeth, trauma of tooth germ, infection of tooth germ, displacement of tooth germ or tooth by a neoplasm, ankylosis, overretention of deciduous predecessor, lack of space for the tooth in the dental arch and mucosal barrier due to gingival fibrosis. The maxillary canine is especially important as it has the longest root, provides guidance for lateral movement of the mandible and masticatory function and assumes an important role esthetically as it is located at mouth angle. If left untreated, it may cause migration and external, internal resorption of adjacent teeth, loss of arch length, formation of dentigerous cyst or tumors, infection and referred pain as well as malposition of the tooth. Therefore, periodic examination of the development and eruption of the maxillary canine is especially important in a growing child. This case study presents the results of treatment of palatally impacted maxillary canine utilizing surgical exposure and orthodontic tooth movement on patients visiting SNUDH dept. of pediatric dentistry.

• 대한소아치과학회지
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• 제35권2호
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• pp.333-338
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• 2008

과잉치란 정상에 비해 많은 수의 치아를 일컫는 것으로 유치열기와 혼합치열기에 발생하며, 여러 가지 임상적 문제를 일으킬 수 있다. 특히 상악 전치부의 과잉치는 상악 전치의 맹출 장애 및 전위, 정중부의 치간 이개, 치근 흡수, 함치성낭종 형성 등의 문제를 유발할 수 있으므로 조기에 진단하고, 과잉치의 위치 및 수, 형태에 따라 적절한 치료를 시행하는 것이 중요하다. 이 증례는 상악 전치부에 네 개의 과잉치가 영구치의 맹출을 방해하고 있는 경우로, 발거 시 합병증을 최소화하기 위하여 두 단계로 나누어 발거하였다. 컴퓨터 단층 촬영에서 네 개의 과잉치가 주위의 영구치 맹출을 방해하고 있었고, 그 중 두 개의 과잉치는 절치 치배에 매우 근접해 있었다. 네 개의 과잉치를 동시에 제거할 경우 영구 치배에 손상을 줄 위험이 있으므로 두 개의 역위 매복된 원추형의 과잉치만 먼저 발거하였다. 남은 두 개의 과잉치는 위치가 변화되기를 기다린 후 두 번째 발거 수술을 시행하여, 주위 절치 치배에 손상을 가하지 않고 치조골 삭제를 적게 하여 합병증 발생을 줄일 수 있었다.

• 대한소아치과학회지
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• 제28권2호
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• pp.238-246
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• 2001

본 실험은 탁월한 골유도능으로 관심의 대상이 되고 있는 BMP의 세포내 신호 전달자로 알려진 Smad 1과 Smad 5가 조골세포 초기 분화표지인자인 ALP 유전자의 발현에 미치는 영향 및 그 조절기전을 알아보고자 하였다. BMP 처리 없이도 Smad에 의해 ALP가 발현되는가를 알아보기 위해 Smad 1과 Smad 5가 각각 stably transfection된 C2C12 세포를 3일간 배양후 histochemical assay를 하였고, Smad 1과 Smad 5의 expression vector와 ALP promoter vector를 transient co-transfection한 후 ALP promoter activity를 측정하였다. Smad에 의한 BMP의 효과를 알아보기 위해서 100ng/ml의 BMP-2를 처리한 군과 처리하지 않은 군으로 나누어 세포를 배양한후 ALP 유전자의 발현을 northern blot analysis로 확인 하였다. Smad가 ALP 유전자의 발현을 직접적으로 조절하는가를 알아보기 위해서는 단백질 합성억제제인 cycloheximide를 전처리하여 ALP 유전자의 발현을 northern blot analysis하였다. 이상의 실험결과 다음과 같은 결론을 얻었다. $\cdot$ Smad 1과 Smad 5가 과발현된 세포에서는 BMP 처리없이도 ALP가 발현된다. $\cdot$ Smad 1과 Smad 5가 과발현된 세포에서 BMP 처리후 ALP 발현 증가율이 대조군 보다 현저히 높게 나타나 Smad가 BMP 효과를 증가시킨다는 것을 알 수 있다. $\cdot$ Smad는 새로운 단백질의 합성을 통해 ALP 유전자를 발현시킨다.