• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.500-514
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• 1996

The purpose of this study was to observe the tissue response in applying staples and various suture materials to both scalp and buccal mucosa in rabbits. 18 rabbits were divided into 6 groups. The incised wounds of both scalp and buccal mucosa were sutured with staples, polyglactin 910, chromic catgut, mer silk and nylon. The experimental animals were sacrificed after 1, 3, 5, 7, 10, 14 days posto peratively 3 animals at one time. The tissue was stained with Hematoxylin and eosin, and Masson's Trichrom. In light microscopic examinations, the sutured sites were examined histologi cally according to 6 degrees about inflammation and collagen deposit. The results were obtained as follows, 1. The chromic catgut, an absorbable suture material, was absorbed by 7 days, whereas polyglactin 910 and mersilk began to get absorbed after 7 days. 2. Mersilk manifested a broad range of inflammation in the scalp, and both staple and nylon showed a severe inflammatory reaction in the buccal mucosa. 3. With polyglactin 910, both tissue samples showed only minor foreign body reaction, however in the scalp, the process of fibrosis took place compara tively slowly, whereas in the buccal mucosa, it occurred promptly and manifested active fibrosis by 7 days. 4. Mersilk showed widespread a matrix formation in both scalp and buccal mucosa, and showed the most severe inflammatory reaction by 3 days, which did not seem to decrease even after 7 days. 5. Both staple and nylon showed relatively a severe inflammatory reaction, however fibrosis took place rather promptly compared to the other groups. 6. Generally, in the buccal mucosa fibrosis occurred more promptly than in the scalp in both control and experimental groups. 7. Retention of the suture material and stability of the knot were the best with the staple, and better stability was manifested by the multi-stranded poly glactin 910 and mersilk than singlestranded chromic catgut and nylon. From above results, in the buccal mucosa absorbable suture materials especially polyglactin 910 showed better response in the aspect of inflammatory reaction, while in the scalp monofilament suture materials such as staple and nylon manifested a early fibrosis and collagen formation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.3
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• pp.205-211
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• 2001

Cleft palate is one of the most serious congenital anomalies in human that causes a sucking problem in newborn babies and morphologic deformity that usually leads to death in newborn mouse offspring due to an insufficient ability to suck milk. Therefore cleft palate had been researched with epidemiologic and molecular methods, and many etiologic factors were examined closely. Among of the research methods, biologic molecule researches have been more important method for cleft palate formation study. The $TGF-{\beta}$ had an important role in the cell migration, epithelial-mesenchymal transdifferentiation, extracellular matrix synthesis and deposition. But there was a little research which was study about correlation cleft palate induced by beta-aminonitroproprionitrile(BAPN) with $TGF-{\beta}$ expression. A purpose of this presented study was examed how $TGF-{\beta}$ expression in cleft palate mice. At gestation days 13, BAPN-monofumarate salts($(C_3H_6N_2)_2$ ${\cdot}$ $C_4H_4O_4$, Sigma Co.) was single oral administered to 4 pregnant rats according to 1g/kg body weight. And pregnant rats were sacrificed on day 20 post coitus(p.c.), The $TGF-{\beta}$ expression patterns of cleft formed fetus mice was followed that; 1.Osteoblast, mesenchymal cell and epithelial cell of cleft mice were low expression compare to control mice. 2.There was no $TGF-{\beta}$ difference expression pattern of osteocyte of cleft mice compare to control mice. 3. In western blot analysis, thickness of band of $TGF-{\beta}$ in cleft mice was thin and dilute compare to control mice.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.4
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• pp.350-364
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• 1995

As early as 1889, treatment of ostemyelitis was reported using xenogeneic demineralized bone. In 1965, Urist discovered that demineralized long bone fragment, even when implanted in nonskeletal tissue, would stimulate osteogenesis. The clinical use of demineralized bone of Oral and Maxillofacial surgery is not new. The demineralized bone implants were used for 1) interposition within osteotomy gaps, cystic detects, alveolar clefts ; 2) augmentation, over intact bone surfaces ; 3) construction of new bone within soft tissue. Demineralized bone grafts invokes a induced osteogenesis which is the transformation of host cells into osteoblasts. Demineralized bone has identified several factors that modulate the osteogeneic response : sterilization method, recipient age, particle size etc. Especially, pulverization of bone matrix may enhance its osteoinductive properties, to allow rapid, efficient bridging of large defects. the purpose of the present report was to describe the potential efficacy of demineralized allogeneic bone powder of skull of rabbits as a particle size ; 212 ${\mu}m$, 710 ${\mu}m$, 1 mm each other. Microscopic finding in our experimental studies shown that 710 ${\mu}m$ demineralized bone powder is the most potent osteogenic response, and then 212 ${\mu}m$, 1 mm size. Densitometric analysis shown that density of all group was continue to increase until 4 weeks after operation, and then continue to decrease.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.28.1-28.7
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• 2015

Background: The aim of this study was to present three-dimensional (3D) structural characteristics of the mandible in the hemifacial microsomia. The mandible has six distinct functional units, and its architecture is the sum of balanced growth of each functional unit and surrounding matrix. Methods: In order to characterize the mandibular 3D architecture of hemifacial microsomia, we analyzed the mandibular functional units of four hemifacial microsomia patients using the 3D reconstructed computed tomography (CT) images. And we compared the functional unit size between affected and non-affected side. Results: The length of condyle and angle showed significant differences between affected and non-affected sides. However, the length of mandibular body showed insignificant differences. The size differences between affected and non-affected side were observed at the condyle, angle, and body in descending order. Conclusions: This preliminary study suggests that the main etiopathogenic units are condyle and angle in the hemifacial microsomia mandible. Further investigation with the increased number of subjects will be helpful to establish treatment modality by etiopathogenic targeting of hemifacial microsomia.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.2
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• pp.73-81
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• 2013

Purpose: Smad4 is a central mediator for transforming growth factor-${\beta}$/bone morphogenetic protein ($TGF-{\beta}/BMP$) signals, which are involved in regulating cranial neural crest cell formation, migration, proliferation, and fate determination. Accumulated evidences indicate that $TGF-{\beta}/BMP$ signaling plays key roles in the early tooth morphogenesis. However, their roles in the late tooth formation, such as cellular differentiation and matrix formation are not clearly understood. The objective of this study is to understand the roles of Smad4 in vivo during enamel and dentin formation through tissue-specific inactivation of Smad4. Methods: We generated and analyzed mice with dental epithelium-specific inactivation of the Smad4 gene (K14-Cre:$Smad4^{fl/fl}$) and dental mesenchyme-specific inactivation of Smad4 gene (Osr2Ires-Cre:$Smad4^{fl/fl}$). Results: In the tooth germs of K14-Cre:$Smad4^{fl/fl}$, ameloblast differentiation was not detectable in inner enamel epithelial cells, however, dentin-like structure was formed in dental mesenchymal cells. In the tooth germs of Osr2Ires-Cre:$Smad4^{fl/fl}$ mice, ameloblasts were normally differentiated from inner enamel epithelial cells. Interestingly, we found that bone-like structures, with cellular inclusion, were formed in the dentin region of Osr2Ires-Cre:$Smad4^{fl/fl}$ mice. Conclusion: Taken together, our study demonstrates that Smad4 plays a crucial role in regulating ameloblast and odontoblast differentiation, as well as in regulating epithelial-mesenchymal interactions during tooth development.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.2
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• pp.91-99
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• 2012

Purpose: The purpose of this study was to evaluate the expression of osteogenic genes associated with bone regeneration on anodizing titanium surface. Methods: $20{\times}20{\times}1$ (mm) commercially pure titanium plate was made, one group was pure titanium, second group was punched, and last group was punched and anodized by electrochemical method. Through the osteogenic cell culture model, the expression of extracellular matrix proteins, such as bone morphogenetic protein-2, bone sialoprotein, aggrecan, osteocalcin, Alkaline phosphatase, collagen I had been evaluated by Real-time polymerase chain reaction, and the morphology of growing cells was evaluated by scanning electron microscopy. Results: The attachment of mesenchymal stem cell was even and well-oriented on all Ti surfaces. The osteogene expression was increased on punching groups but, decreased on anodizing surfaces in 3 week samples. Conclusion: Punched anodizing Ti has possibility be using as a dental implant material, but further in vivo study would be needed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.6
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• pp.499-508
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• 2007

Background and Purpose: Some subtypes of malignant salivary gland tumors such as adenoid cystic carcinoma (ACC) frequently result in distant metastasis of vascular origin, which are main causes of treatment failure. The reasons for the affinity for vascular metastatic potential are unclear. Therefore, molecular characteristics that influence the dissemination of metastatic tumor cells are important for the design of more effective treatment of salivary ACC. Tumor angiogenesis has been known to be essential for the distant metastasis of malignant cells. So, we determined expressions of vascular metastasis related factors in orthotopic (parotid) murine models of parotid ACC and compared with those in ectopic (subcutis) tumors of athymic mice. Experimental Design: Using specimens from murine parotid (orthotopic, experimental group) and subcutaneous (ectopic, control group) tumors, which have developed via transplantation of tumor cells, originated from human parotid ACC, we performed immunohistochemical assays with anti-vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF, FGF2), matrix metalloproteinase (MMP)-9, and interleukin (IL)-8 antibodies. We also performed immunohistochemical assays with VEGF receptor (VEGFR)-1, VEGFR-2, VEGFR-3, and phosphorylated VEGFR-2. Results: Transplantation of human ACC tumor cell $(5{\times}10^5)$ into the parotid and subcutis successfully resulted in orthotopic (parotid) and ectopic (subcutaneous) tumors in athymic mice. Immunohistochemical staining demonstrated higher expression of major angiogenic factors (VEGF, bFGF, MMP-9) in the orthotopic tumors than in ectopic tumors (P<0.05). But the expression level of angiogenic receptors were same in orthotopic and ectopic tumors of parotid ACC. Conclusion: VEGF, bFGF, and MMP-9 could be a good candidates for antiangiogenic therapy for the contol of vascular metastatic lesions of salivary ACC.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.1
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• pp.10-23
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• 2007

Hallmarks of clinical behaviors of adenoid cystic carcinoma(ACC) of salivary glands are the delayed onset of vascular metastasis and poor responses to classical chemotherapeutic agents. Poor prognoses from salivary ACC are caused by lung metastases that are resistant to conventional therapy. Therefore, cellular and molecular characteristics that influence the dissemination of metastatic cells are important for the design of more effective treatment of salivary ACC. Tumor angiogenesis has been known to be essential for the distant metastasis of malignant cells. So, we determined expressions of angiogenic proteins in benign (pleomorphic adenoma) and malignant (ACC, mucoepidermoid carcinoma) tumors of salivary glands and compared each other and to those in oral squamous cell carcinoma. Using surgical specimens, we performed immunohistochemical assays with anti-vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), phosphorylated VEGFR-2 (pVEGFR-2), matrix metalloproteinase (MMP)-9, and interleukin (IL)-8 antibodies. Most angiogenic factors were overexpressed in malignant salivary tumors than in pleomorphic adenoma which is benign nature. Moreover, ACC demonstrated more expression of VEGFR-2 than that of squamous cell carcinoma which used as control. Conclusively, these data show those angiogenic factors produced by salivary gland tumors may affect the propagation and metastasis of malignant cells of salivary tumors, and could be used as biomarkers for the malignant transformation of salivary gland tumors. Prospectively, although further studies will be needed, these biomarkers related to angiogenesis can be molecular targets for the therapy of salivary ACC, which has propensity for delayed vascular metastasis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.281-286
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• 2009

Introduction: Enamel matrix derivative (EMD) is a protein which is secreted by Hertwig root sheath and plays a major role in the formation of cementum and attachment of peridontium. Several studies have shown that EMD promoted the proliferation and differentiation of preosteoblasts, osteoblasts and periodontal ligament cells in vitro: however, reports showing the inhibition of osteogenic differentiation by EMD also existed. This study was designed to simultaneously evaluate the effect of EMD on the two cell lines (human mesenchymal stem cells: hMSC, human periodontal ligament derived fibroblasts: hPDLCs) by means of quantitative analysis of some bone related matrices (Alkaline phosphatase : ALP, osteopontin ; OPN, osteocalcin ; OC). Materials and Methods: hMSCs and hPDLCs were expanded and cells in the 4${\sim}$6 passages were adopted to use. hMSc and hPDLCs were cultured during 1,2,7, and 14 days with 0, 50 and 100 ${\mu}g/ml$ of EMD, respectively. ALP activity was assessed by SensoLyte ALP kit and expressed as values of the relative optical density. Among the matrix proteins of the bony tissue, OC and OPN were assessed and quantification of these proteins was evaluated by means of human OC immunoassay kit and human OPN assay kit, respectively. Results: ALP activity maintained without EMD at $1,2^{nd}$ day. The activity increased at $7^{th}$ day but decreased at $14^{th}$ day. EMD increased the activity at $14^{th}$ day in the hPDLCs culture. In the hMSCs, rapid decrease was noted in $7^{th}$ and $14^{th}$ days without regard to EMD concentrations. Regarding the OPN synthesis in hPDLCs, marked decrease of OPN was noted after EMD application. Gradual decrease tendency of OPN was shown over time. In hMSCs, marked decrease of OPN was also noted after EMD application. Overall concentration of OPN was relatively consistent over time than that in hPDLCs. Regarding the OC synthesis, in both of hPDLCs and hMSCs, inhibition of OC formation was noted after EMD application in the early stages but EMD exerted minimal effect at the later stages. Conclusion: In this experimental condition, EMD seemed to play an inhibitory role during the differentiation of hMSCs and hPDLCs in the context of OC and OPN formation. In the periodontium, there are many kinds of cells contributing to the regeneration of oral tissue. EMD enhanced ALP activity in hPDLCs rather than in hMSCs and this may imply that EMD has a positive effect on the differentiation of cementoblasts compared with the effect on hMSCs. The result of our research was consistent with recent studies in which the authors showed the inhibitory effect of EMD in terms of the differentiation of mineral colony forming cells in vitro. This in vitro study may not stand for all the charateristics of EMD; thus, further studies involving many other bone matrices and cellular attachment will be necessary.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.1
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• pp.63-79
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• 1993

To repair bony defects with tansplanted bone in the body, fresh autogenous bone is undoubtly, the most effective bone graft for clinical applications. But the demineralized bone has the matrix-induced bone formation which was suggested by Urist in 1965. Many authors assisted that demineralized bone powder induces phenotypic conversion of mesenchymal cells into osteoblasts, with high-density bone formation. The process of inducing differentiated cells becomes osteogenic properties. The purpose of this study was to evaluate the osteoinductive capacity of allogenic freeze-dried demineralized bone block (FDD, $7{\times}7mm$) and to compare FDD with the same sue of deep-frozen allogenic bone(DF), fresh autogenous bone (A) after implantation. The histological and ultrastructural features of tissue responses were examined after 1, 2, 4, 6, 8 weeks implantation of each experimental groups in the operative site of the New Zealand white rabbits. The results were as follows : 1. Inflammatory cell infiltration generally has appeared at 1 week, but reduced at 4 weeks in each group, but most severe in DF group. 2. Osteoblastic activity has increased for 4 weeks, but decreased at 6 weeks in each group and there was no significant difference among experimental groups. 3. New bone formation has begun at 1week, least activations in A groups, and showed the revesal line of bone formation among each group at 6 to 8 weeks. 4. Bone resorption has appeared at 1 week, but disappeared at 4 weeks in both A and DF groups, but more severe in DF than A groups. 5. In ultrastructural changs, the DF group have showed the most remarkable osteoclastic activities among experimental groups. 6. Osteoid or tangled collagen fibrils near the implanted sites were replaced by more mature, lamellated bony trabeculae during bone remodeling. There was little difference among each experimental groups. 7. During the convertion osteoblasts to osteocytes which embedded within the bone matrix, there was organ-less-poor cytoplasm, increased nuclear chromatin, abundant rough endothelial reticulum (RER) in each groups. From the above the findings, the DF group shored more bone resorption and foreign body reaction than FDD and A groups, and FDD group showed more new bone formation or osteoblastic activity than DF and A groups in early stage. There was no significant difference of cellular activities among the FDD DF, and A groups according to the time.