• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권3호
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• pp.238-246
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• 2007

This study is aimed to elucidate the abnormal growth pattern of human fetal maxilla with cleft lip and palate (CLP). Total 71 fetal maxillae with CLP were obtained from aborted human fetuses. They were examined radiologically for the dimensional changes of maxillary trapezoid (MT) formed by maxillary primary growth centers (MxPGC)(Lee et al., 1992). In palatal radiogram of the CLP maxilla, the MT was traced by the anterior and posterior MxPGCs, and the dimensions of anterior and posterior maxillary widths, maxillary length, and MT length (MTL), and MT area were measured for evaluation of the basic growth pattern of the developing maxilla. The growth of anterior and posterior MxPGCs was severely retarded in the prenatal maxillae with CLPs, showing abnormal shape of MT. Cleft lip subjects without cleft palate also showed arrested growth of MT. Unilateral cleft lipalveolar cleft or cleft palate (UCL-AC/CP) and bilateral cleft lip-alveolar cleft or cleft palate (BCL-AC/CP) showed enhanced abnormal MT pattern. The abnormality of MT was most marked in BCL-AC/CP. It was also observed that the craniofacial malformations other than CLPs produced abnormal MT. In conclusion, the MT growth of prenatal CLP maxilla was severely arrested and resulting in abnormal MT shape on the palatal radiogram. BCL-AC/CP showed more protruded nasal septum than other types of CLPs, while UCL-AC/CP showed severe deviation of the protruded nasal septum towards the non-cleft side. Cleft lip only subjects also showed the abnormal growth of MT. These data suggest that the MT is primarily involved in CLPs, and MT shape could be utilized as a sensitive indicator for the analysis of maxillary malformation in different types of CLPs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권4호
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• pp.330-336
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• 2001

Angiogenesis is an essential process for the growth, invasion and metastasis of cancer. However, it is uncertain that antiangiogenic effects can be a major treatment strategy of oral cancer. The aim of this study was to investigate whether thalidomide, which is known to be a potent inhibitor of angiogenesis, have inhibitory effect on the growth and antiangiogenic effects of oral squamous cell carcinoma(OSCC) xenografted in nude mice and whether antiangiogenesis of thalidomide can be included as a major treatment strategy of oral cancer. After human oral squamous cell carcinoma strain KB was subcutaneously implanted in 20 nude mice, the volume of tumor was measured every three days. When the tumor mass reached $75{\sim}100mm^3$, thalidomide(200mg/kg/d) was administered into 10 experimental nude mice and the same volume of distilled water was administered into 10 control nude mice and the tumor volume was measured every three days. The excised tumor masses on the 30th day after administration were frozen and processed for immunohistochemistry using vascular endothelial growth factor(VEGF) and CD31. We evaluated microvessel density and VEGF expression. The results were as follows ; 1. Thalidomide retarded the growth of human OSCC as compared with the control group, but it was not statistically significant. 2. A statistically significant lower microvessel density was observed in the thalidomide-treated group than in the control group(p<0.01) and thalidomide significantly reduced VEGF expression (p<0.01). Thalidomide exhibited significantly antiangiogenic effect, but did not inhibit the growth of human OSCC effectively. Antiangiogenic therapy of thalidomide alone is not likely to be effective in the treatment of human OSCC, but might be regarded as adjuvant chemotherapeutic strategy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권2호
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• pp.147-154
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• 2002

Genistein that is a component of soy has been reported to have a protective effect on the carcinogenesis of various tumors and to inhibit the growth of a wide variety of tumor cell in vitro. Angiogenesis is an essential process for the carcinogenesis, growth, invasion and metastasis of cancer and genistein has been suggested to act as natural anti-angiogenic agent. The purpose of this study was to evaluate the effects of genistein on the vascular endothelial growth factor (VEGF) expression in hamster buccal pouch oral carcinogenesis model induced by 9, 10-dimethyl 1,2-benzanthracene (DMBA). Experimental group that were supplied with 0.1mg/day genistein were sacrificed by time schedules and routinely processed for immunohistochemical examination of VEGF. In genistein treated group, carcinogenesis was retarded with respect to the acanthosis, hyperkeratosis, and epithelial dysplasia. Immunohistochemical study showed that the VEGF protein of genistein group was less expressed than that of the control group. (p<0.05) Thus, it is postulated that genistein has chemopreventive effect on the oral carcinogenesis, and this chemopreventive effect, at least partly, is originated from the anti-angiogenic effect of genistein

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.5.1-5.8
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• 2018

Background: The objective of this study was to evaluate the influence of masticatory muscle injection of botulinum toxin type A (BTX-A) on the growth of the mandibular bone in vivo. Methods: Eleven Sprague-Dawley rats were used, and BTX-A (n = 6) or saline (n = 5) was injected at 13 days of age. All injections were given to the right masseter muscle, and the BTX-A dose was 0.5 units. All of the rats were euthanized at 60 days of age. The skulls of the rats were separated and fixed with 10% formalin for micro-computed tomography (micro-CT) analysis. Results: The anthropometric analysis found that the ramus heights and bigonial widths of the BTX-A-injected group were significantly smaller than those of the saline-injected group (P < 0.05), and the mandibular plane angle of the BTX-A-injected group was significantly greater than in the saline-injected group (P < 0.001). In the BTX-A-injected group, the ramus heights II and III and the mandibular plane angles I and II showed significant differences between the injected and non-injected sides (P < 0.05). The BTX-A-injected side of the mandible in the masseter group showed significantly lower mandibular bone growth compared with the non-injected side. Conclusion: BTX-A injection into the masseter muscle influences mandibular bone growth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권2호
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• pp.97-108
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• 2011

Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권1호
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• pp.1-7
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• 2009

Purpose: The purpose of this study is to investigate the therapeutic use of Hepatocyte growth factor(Adv.CMV.HGF) in temporomandibular joint disc defect. Materials and methods: Twelve New Zealand white rabbits, weighing 2.5 - 3.0 kg, were used in this experiment. Defects(2 mm in diameter) were created in their TMJ discs. Recombinant Adv.CMV.HGF with gelatin sponge($Gelfoam^{(R)}$) as carrier was implanted in the defects. We divided the rabbits into four batches according to the duration of the implantation - of 1, 4, 8, 12 weeks - and both left and right TMJ of each rabbit in all groups were used in the research : left joints were used as experiment group and right were control group. Each batch of rabbits was killed one, four, eight and twelve weeks after the experimentation respectively, and called Group A, B, C, and D. (Group A = 1 wk, B = 4 wks, C = 8 wks, and D = 12 wks) Results: The experimental group showed a significant increase in the number of chondroblasts and active cell differentiation at the margin of the defects. Compared to the control group, in the experiment group chondroblasts increased and chondrocytes showed a columnar arrangement, which is witnessed at the time of cell differentiation. Conclusion: This study supports the case that Avd.CMV.HGF may be useful in the repair of articular disc of the rabbit TMJ.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권1호
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• pp.27-34
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• 2009

Angiogenesis is essential for solid tumor growth and progression. Among the pro-angiogenetic factors, vascular endothelial growth factor(VEGF), also known as vascular permeability factor, is the most important as a mitogen for vascular endothelium. The VEGF family of molecules currently consists of six growth factors, VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-E, and placenta growth factor(PlGF). Over-expression of PlGF is associated with angiogenesis under pathological conditions such as ischemia, inflammation, and cancer. Hence, the goal of this study is to identify the correlation of clinicopathlogical factors and the up-regulation of PlGF expression in oral squamous cell carcinoma. We studied the immunohistochemical staining of PlGF, PlGF gene expression and a real time quantitative RT-PCR in 20 specimens of 20 patients with oral squamous cell carcinoma. The results were as follows. 1. In the immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, the high level staining of PlGF was observed. And the correlation between immunohistopathological PlGF expression and histological differentiation of specimens was significant (Pearson correlation analysis, significance [r] >0.6, P < .05). 2. In the PlGF gene RT-PCR analysis, PlGF expression was more in tumor tissue than in adjacent normal tissue. Paired-samples analysis determined the difference of PlGF mRNA expression level between the cancer tissue and the normal tissue (Student's t - test, P < .05) These findings suggest that up-regulation of the PlGF gene may play a role in progression and local metastasis in invasive oral squamous cell carcinoma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권2호
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• pp.55-65
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• 2009

Purpose: We determined the therapeutic effects of blockade of epidermal growth factor(EGF) and vascular endothelial growth factor(VEGF) receptor tyrosine kinases on the growth of oral squamous cell carcinoma(OSCC) xenografted in athymic nude mice. Experimental Design: We investigated the in vivo antitumor effects of a tyrosine kinase inhibitor for EGFR and VEGFR-2, AEE788 in a mouth floor(orthotopic) tumor model. Nude mice with orthotopic tumors were randomized to receive AEE788, paclitaxel, a combination of AEE788 and paclitaxel, or control. Antitumor mechanisms of AEE788 were determined by immunohistochemical/immunofluorescent and apoptosis assays. Results: Tumors of mice treated with AEE788 demonstrated down-regulation of phosphorylated EGFR, phosphorylated VEGFR and their downstream mediators(pMAPK and pAkt), decreased proliferative index, decreased microvessel density(MVD). As a result, growth of the primary tumor and nodal metastatic potentials were inhibited by AEE788. Conclusion: These data show that EGFR and VEGFR can be molecular targets for the treatment of OSCC.

• 대한치과의사협회지
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• 제53권1호
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• pp.28-35
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• 2015

To overcome shortcoming of autogeneous, allogenic, xenogenic and alloplastic bone grafts, various growth factors related to bone regeneration have been identified and developed. Among them, rhBMP-2 is regarded as the most potent osteoinductive growth factor and it can trigger the differentiation of mesenchymal stem cells to osteogenic cells for accelerated new bone formation And several commercial products of rhBMP-2 are available in Korea. It is applied to maxillary sinus augmentation, guided bone regeneration and preservation of extraction socket. In this review, the development, action mechanism and clinical applications of rhBMP-2 will be described.

• 대한구순구개열학회지
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• 제14권1_2호
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• pp.37-44
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• 2011

Amniotic fluid is a complex and biological reservoir that provides mechanical cushioning and has many nutrients required for fetal growth and development. During our main research works about the fetal surgery of congenital facial defects, we reviewed several recent articles about the effectiveness and composition of amniotic fluid. Among these review processes, amniotic fluid, as the convenient medium to store sking grafts, was focused especially for its growth factors and rich nutrients, and we summarized some experimental investigations of skin grafts stored in amniotic fluid in rats. We reviewed mainly the article, "Turhan-haktanir N. et al. Histological assessment of skin grafts in amniotic fluid and saline. J Plast Surg Hand Surg 2010;44:226-30."