• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.511-522
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• 2007

Introduction : The purpose of this study was to evaluate the possibility of the acellular dermal matrix (ADM) as a barrier membrane for bone regeneration, and to evaluate the osteogenic effect of ADM as a carrier system for rhBMP-2 in the rat calvarial defect model. Materials and Methods: An 8-mm, calvarial, critical-size osteotomy defect was created in each of 60 male Spraque-Dawley rats(weight $250{\sim}300g$). Three groups of 20 animals, each received either rhBMP-2(0.025mg/ml) in an ADM carrier, ADM only, or negative surgical control. And each group was divided into 2- and 8-weeks healing intervals. The groups were evaluated by histologic and histomorphometric parameters(10 animals/group/healing intervals). Data were expressed as $means{\pm}standard$ deviations($m{\pm}SD$). Comparisons between experimental and control groups were made using two-way ANOVA and post hoc t-test. Comparisons between 2 weeks and 8 weeks were made using paired t-test. The level of statistical difference was defined as P< 0.05. Results : The ADM group and rhBMP-2/ADM group results in enhanced local bone formation in the rat calvarial defect at both 2 and 8 weeks. The amount of defect closure and new bone formation were significantly greater in the rhBMP-2/ADM group relative to ADM group(P<0.05). At 8 weeks, the majority of ADM in the defect was contracted, and integrated with surrounding host tissues. In addition, host cell infiltration and neovascularization of the ADM in the absence of an inflammatory response were observed, and the newly formed bone around ADM showed a continuous remodeling and consolidation. Conclusion : The results of the present study indicated that ADM may be used as a barrier membrane for bone regeneration and that may be employed as a delivery system for BMPs.

• Journal of Periodontal and Implant Science
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• 제25권3호
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• pp.703-719
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• 1995

The purpose of this study was to observe the effects of the periodontal ligament on the healing and the formation of alveolar bone in the extraction socket, when this ligament had artificially remained in the socket during the tooth removal. Twenty rats aged 4 weeks were used and devided into the control groups (10) and the experimental groups (10) in this study. The maxillary right and left first molars were extracted in both groups. In the experimental groups the periodontal ligament was remained in the extraction sockets using 0.4% ${\beta}-aminopropionitrile$, and in the control the periodontal ligament was completely removed by curettage. At 1, 3, 5, 7 and 14 days after the tooth extraction, rats in both groups were serially sacrificed. And the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows ; 1. On 1 day, the periodontal ligament was only found in the extraction socket walls of the experimental groups, and there was not the distinguishable difference between the control and the experimental groups. 2. On 3 days, there were more collagen fibers and the appearance of higher cellular density in the experimental groups than in the control. And the cells and collagen of the periodontal ligament were so actively proliferated and synthesized that invaded into the connective tissue of the extraction sockets in the experimental groups. 3. In the experimental groups, the trabecular bone was formed on the basal and lateral bone surface on 5 days. However, there was not the new bone forming appearance in the control groups at this time. 4. On 7 days, the trabecular bone was formed in the control groups. 5. On 14 days, the extraction sockets were almost entirely filled with the bony trabeculae in both groups. But, compared to the control group, the experimental groups showed the prominent differences in the amount & the density of the new bone formed. In conclusion, it was suggested that the residual periodontal ligament tissue in the extraction socket will play a major role as the important cell source in the healing and the new bone formation of the extraction socket.

• 대한치과교정학회지
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• 제33권4호
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• pp.279-291
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• 2003

낮은 강도의 전류는 골세포의 활성화 대사를 증가시키는 것으로 알려져 왔다. 이 연구는 초소형 전기 장치에 의한 전기 자극이 교정적 치아 이동에 미치는 영향을 규명하기 위하여, 체중 3kg내외의 고양이 6마리를 대상으로 가철성 교정장치와 NiTi coil spring(75gm)을 사용하여 상악 견치를 이동시켰다. 실험군측 견치에는 교정력과 간헐적인 $20{\mu}A$의 전기 자극을 가하였고, 대조군측에는 같은 크기의 교정력만을 가한 후 4주 동안의 치아 이동량을 측정하여 비교하였으며, 치아를 중심으로 조직을 절취하여 탈회하고 조직 처리 후 광학 현미경으로 치주조직의 변화를 비교하여 다음과 같은 결론을 얻었다. 1. 28일간의 실험 기간 동안 실험측의 치아 이동량은 대조군에 비하여 현저히 증가하여, 4주후에 실험측의 치아는 대조군에 비하여 37% 증가된 이동량을 기록하였다. 2. 전기 자극을 받은 치아의 치근 견인측에서 대조군에 비하여 조직학적으로 증가된 골형성 양상이 관찰되었다. 3. 28일간의 전기 자극과 교정력으로 실험측 치아의 압박측에서 대조군에 비하여 증가된 골 흡수 양상이 관찰되었다. 4. 실험군 견치 치근 주위 조직에서는 전반적으로 더 많은 수의 조골 및 파골 세포들과 모세 혈관, 골양 조직들이 관찰됨으로써 증가된 조직 세포 활성을 반영하였다. 5. 1일 5시간 동안의 간헐적 전류 자극은 치아 이동량을 증가시키고 조직 개조를 활성화시키는 효과가 있었다. 이상의 결과는 외부에서 가한 낮은 강도의 간헐적 전기 자극으로 교정적 치아 이동량이 많아지고 치주 조직의 개조 활성이 증가됨을 보이므로 초소형 전기 장치에 의한 자극은 치아 이동과 주위 조직 개조를 촉진시킬 가능성이 있을 것으로 평가되었다.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.345-359
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• 2006

Loss of maxillary molar teeth leads to rapid loss of crestal bone and inferior expansion of the maxillary sinus floor (secondary pneumatization). Rehabilitation of the site with osseointegrated dental implants often represents a clinical challenge because of the insufficient bone volume resulted from this phenomenon. Boyne & James proposed the classic procedure for maxillary sinus floor elevation entails preparation of a trap door including the Schneiderian membrane in the lateral sinus wall. Summers proposed another non-invasive method using a set of osteotome and the osteotome sinus floor elevation (OSFE) was proposed for implant sites with at least 5-6mm of bone between the alveolar crest and the maxillary sinus floor. The change of grafted material in maxillary sinus is important for implant survival and the evaluation of graft height after maxillary sinus floor elevation is composed of histologic evaluation and radiomorphometric evaluation. The aim of the present study was radiographically evaluate the graft height change after maxillary sinus floor elevation and the influence of the graft material type in height change and the bone remodeling of grafts in sinus. A total of 59 patients (28 in lateral approach and 31 in crestal approach) who underwent maxillary sinus floor elevation composed of lateral approach and crestal approach were radiographically followed for up to about 48 months. Change in sinusgraft height were calculated with respect to implant length (IL) and grafted sinus height(BL). It was evaluated the change of the graft height according to time, the influence of the approach technique (staged approach and simultaneous approach) in lateral approach to change of the graft height, and the influence of the type of graft materials to change of the graft height. Patients were divided into three class based on the height of the grafted sinus floor relative to the implant apex and evaluated the proportion change of that class (Class I, in which the grafted sinus floor was above the implant apex; Class II, in which the implant apex was level with the grafted sinus floor; and Class III, in which the grafted sinus floor was below the implant apex). And it was evaluated th bone remodeling in sinus during 12 months using SGRl(by $Br\ddot{a}gger$ et al). The result was like that; Sinus graft height decreased significantly in both lateral approach and crestal approach in first 12 months (p$MBCP^{TM}$ had minimum height loss. Class III and Class II was increased by time in both lateral and crestal approach and Class I was decreased by time. SGRI was increased statistically significantly from baseline to 3 months and 3 months(p<0.05) to 12 months(p$ICB^{(R)}$ single use, more reduction of sinusgraft height was appeared. Therefore we speculated that the mixture of graft materials is preferable as a reduction of graft materials. Increasing of the SGRI as time goes by explains the stability of implant, but additional histologic or computed tomographic study will be needed for accurate conclusion. From the radiographic evaluation, we come to know that placement of dental implant with sinus floor elevation is an effective procedure in atrophic maxillary reconstruction.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.417-424
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• 2009

Osteoclasts, derived from multipotent myeloid progenitor cells, play homeostatic roles in skeletal modeling and remodeling, but may also destroy bone in pathological conditions such as osteoporosis and rheumatoid arthritis. Osteoclast development depends critically on a differentiation factor, the receptor activator of NF-${\kappa}B$ ligand (RANKL). In this study, we found that the hexane soluble fraction of the common fig Ficus carica (HF6-FC) is a potent inhibitor of osteoclastogenesis in RANKL-stimulated RAW264.7 cells and in bone marrow-derived macrophages (BMMs). HF6-FC exerts its inhibitory effects by suppression of p38 and NF-${\kappa}B$ but activation of ERK. In addition, HF6-FC significantly decreased the expression of NFATc1 and c-Fos, the master regulator of osteoclast differentiation. The data indicate that components of HF6-FC may have therapeutic effects on bone-destructive processes such as osteoporosis, rheumatoid arthritis, and periodontal bone resorption.

• 한국치위생학회지
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• 제23권4호
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• pp.219-226
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• 2023

연구목적: 이 연구는 대황 추출물이 골수 유래 대식세포(BMM)에서 파골세포 분화에 미치는 영향을 조사하는 것을 목적으로 한다. 파골 세포는 골 재흡수 및 재형성에 중요한 역할을 하며, 파골 세포의 조절 장애는 다양한 골 관련 질환을 유발할 수 있다. 잠재적인 항염증 특성을 가진 약용 식물인 대황은 뼈 대사를 조절하는 것으로 제안되었다. 연구방법: 생후 5주령의 C57BL/6 마우스의 대퇴골과 경골에서 BMM을 분리하고 M-CSF(mouse macrophage colony-stimulating factor) 존재하에 3일간 배양한 후 M-CSF와 파골 세포 분화를 유도하기 위한 핵 인자-κB 리간드(RANKL)의 활성화제를 처리하였다. 연구결과: 대황 추출물로 처리하면 BMM에서 파골 세포 분화가 현저하게 억제되었다. 또한 대황 추출물은 파골세포 형성에 필수적인 유전자인 TRAP(tartrate-resistant acid phosphatase) 및 CTSK(cathepsin K)의 mRNA 발현을 억제하였다. 또한 파골세포 분화에 중요한 전사 인자인 활성화된 T 세포 c1(NFATc1)의 핵 인자의 RANKL 유도 발현을 억제하였다. 결론: 이러한 결과는 대황 추출물이 BMMs에서 파골 세포 형성에 억제 효과가 있음을 나타낸다. 따라서 대황 추출물은 비정상적인 파골 세포 활동과 관련된 뼈 관련 질환의 치료를 위한 유망한 치료제이다. 잠재적인 임상 적용을 완전히 이해하기 위해서는 메커니즘에 대한 추가 연구와 탐색이 필요하다.

• 한국한의학연구원논문집
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• 제13권2호통권20호
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• pp.157-164
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• 2007

An imbalance in bone remodeling that is caused by increased bone resorption over bone formation leads to most adult skeletal diseases including osteoporosis. Since the development of anti-resorptive agents from natural substances has recently gained more interest in the treatment of osteoporosis, we evaluated the effects of 222 natural compounds on receptor activator of $NF-{\kappa}B$ ligand (RANKL)-induced of tartrate-resistance acid phosphatase (TRAP) activity in RAW264.7 murine macrophage cell, and found that berberine chloride is one of compounds inhibiting RANKL-induced TRAP activity. Berberine chloride significantly inhibited the RANKL-induced TRAP activity and the formation of multinucleated osteoclasts in a dose-dependent manner. In addition, berberine chloride prevented the RANKL-induced mRNA expression of TRAP, matrix metalloproteinase 9 and c-Src, which have been known to be highly expressed in the process of osteoclastogenesis. Interestingly, berberine chloride prevented the RANKL-induced activation of extracellular signal-regulated kinase (ERK) which is one of mitogen-activated protein (MAP) kinases. In conclusion, berberine chloride could inhibit the osteoclastogenesis via preventing the activation of ERK/MAP kinase signaling pathway.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.80-86
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• 2006

Cleidocranial dysplasia is rare inherited skeletal dysplasia. It was first reported by Martin in 1765. Subsequently, Marie and Sainton independently documented the criteria of the disease. Cleidocranial dysplasia is a bone disorder caused by a defect in the CBFA1 gene of chromosome 6p21. This gene guides osteoblastic differentiation and appropriate bone formation. Patient with cleidocranial dysplasia has maxillary deficiency, high and narrow palate, prolonged retention of primary teeth, unerupted permanent teeth and supernumerary teeth. Therapeutic options in these patients include of autotransplantation of selected impacted teeth, forced eruption of permanent teeth, full denture, overdenture and implant-supported prosthesis. We report a patient with cleidocranial dysplasia. This patient was treated with implant supported bar overdenture. Despite of gene defect that affects osteoblastic activity, bone remodeling and osseointegration occurred in our patient. So, we report this case with review of literature.

• International Journal of Oral Biology
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• 제34권2호
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• pp.53-59
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• 2009

Periodontal ligament (PDL) tissue is a connective tissue that is interposed between the roots of the teeth and the inner wall of the alveolar bone socket. PDL is always exposed to physiologic mechanical force such as masticatory force and PDL cells play important roles during orthodontic tooth movement by synthesizing and secreting different mediators involved in bone remodeling. The Wnt/${\beta}$-catenin signaling pathway was recently shown to play a significant role in the control of bone formation. In the present study, we applied cyclic tensile stress of 20% elongation to cultured human PDL cells and assessed its impact after six days upon components of the Wnt/${\beta}$-catenin signaling pathway. RTPCR analysis showed that Wnt1a, Wnt3a, Wnt10b and the Wnt receptor LRP5 were down-regulated, whereas the Wnt inhibitor DKK1 was up-regulated in response to these stress conditions. In contrast, little change was detected in the mRNA expression of Wnt5a, Wnt7b, Fz1, and LRP6. By western blotting we found decreased expression of the ${\beta}$-catenin and p-GSK-3${\beta}$ proteins. Our results thus show that mechanical stress suppresses the canonical Wnt/${\beta}$-catenin signaling pathway in PDL cells.

• Animal cells and systems
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• 제4권3호
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• pp.273-278
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• 2000

Transforming growth factor-$\beta$ (IGF-$\beta$)s are multifunctional small polypeptides synthesized in most cell types. TGF-$\beta$ exerts pivotal effects on both bone formation and resorption. In addition, increasing lines of evidence implicate TGF-$\beta$ as a potential coupling factor between these two processes during bone remodeling. In the present study, the expression form and the activation mechanism of latent-TGF-$\beta$ were investigated using specific antibodies for each isoform. TGF-$\beta$s were observed to be synthesized and accumulated in a large amount in cultured osteoblastic cells. The estimated molecular weights of intracellular TGF-$\beta$2 and -$\beta$3 were 49 and 55 kDa, respectively. Based on proteolytic digestion study and immunofluorescence observation, these precursor forms seemed to be accumulated in distinct intracellular compartments. To examine whether the internal pool of TGF-$\beta$ was possiblely regulated by external signals, their biological activites were examined in a conditioned media of this cell. Although the intact conditioned media did not contain detectable TGF-$\beta$ activity, heat-treatment or acid-activation of the conditioned media revealed significant TGF-$\beta$ activity. Furthermore, in the presence of estrogen, this activity was dramatically diminished. It is known that activation of latent TGF-$\beta$ can be achieved by different chemical and enzymatic treatments, or by incubation with certain cell types. This extracellular activation was suggested as a key step in the regulation of TGF-$\beta$ activity. In addition to these extracellular activation, this study suggests that the synthesis and intracellular processing are important regulation steps for TGF-$\beta$ action. In addition, this regulation Is specific for TGF-$\beta$ type 2, because the change was not observed in TGF-$\beta$3 in osteoblastic cell line.