Journal of the Korean Association of Oral and Maxillofacial Surgeons
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- P-ISSN2234-7550
- E-ISSN2234-5930
- SCOPUS, KCI, ESCI
ISSN : 2234-7550
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e-SubmissionVol.35 No.2
Abstract
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.
Abstract
Tumor angiogenesis is a process leading to formation of blood vessels within tumors and is crucial for maintaining a supply of oxygen and nutrients to support tumor growth and metastasis. Vascular endothelial growth factor( VEGF) plays a key role in tumor angiogenesis including induction of endothelial cell proliferation, migration, survival and capillary tube formation. VEGF binds to two distinct receptors on endothelial cells. VEGFR-2 is considered to be the dominant signaling receptor for endothelial cell permeability, proliferation, and differentiation. Bevacizumab(Avastin, Genetech, USA) is a monoclonal antibody against vascular endothelial growth factor. It is used in the treatment of cancer, where it inhibits tumor growth by blocking the formation of new blood vessels. The goal of this study is to identify the anti-tumor effect of Bevacizumab(Avastin) for oral squamous cell carcinoma cell lines. Human squamous cell carcinoma cell line(HN4) was used in this study. We examined the sensitivity of HN4 cell line to Bevacizumab(Avastin) by using in vitro proliferation assays. The results were as follows. 1. In the result of MTT assay according to concentration of Bevacizumab(Avastin), antiproliferative effect for oral squamous cell carcinoma cell lines was observed. 2. The growth curve of cell line showed the gradual growth inhibition of oral squamous cell carcinoma cell lines after exposure of Bevacizumab(Avastin). 3. In the apoptotic index, groups inoculated Bevacizumab(Avastin) were higher than control groups. 4. In condition of serum starvation, VEGFR-2 did not show any detectable autophosphorylation, whereas the addition of VEGF activated the receptor. Suppression of phosphorylated VEGFR-2 and phosphorylated MAPK was observed following treatment with Bevacizumab(Avastin) in a dose-dependent manner. 5. In TEM view, dispersed nuclear membrane, scattered many cytoplasmic vacuoles and localized chromosomal margination after Bevacizumab(Avastin) treatment were observed. These findings suggest that Bevacizumab(Avastin) has the potential to inhibit MAPK pathway in proliferation of oral squamous cell carcinoma cell lines via inhibition of VEGF-dependent tumor growth.
Abstract
In order to make successful oral cancer treatment, we need to understand about tumor biology and effective chemotherapeutic agents. To achieve these studies, it is necessary to develope a proper in-vivo model. Therefore the author will make try to develop more improved animal model of more applicable in various method of cancer study. In this study, the author induced in-vivo tumorigenesis in nude mice by YD-10Bmod cell line used by YD-10B cell line originated from oral tongue squamous cell carcinoma and observed tumor formations and invasiveness of surrounding tissue, and found some results as follows : 1. The experimental group (YD-10Bmod, subcutaneous injection) produced tumors 13 out of 15 mice, while the control group produced none of 5 mice. 2. The inoculation of 1×106cells/mouse produced tumors 3 out of 5 mice and inoculation of 1×107cells/mouse, 2×107cells/mouse produced tumors in every 5 mice. 3. In the histopathologic studies, the inoculation of 1×106cells/mouse group showed the characteristic features of well-differentiated squamous cell carcinoma and demarcated expansile growth, while the inoculation of 1×107cells/mouse, 2×107cells/mouse group showed the expansile growth with partial central necrosis and invasive growth to surrounding fat & connective tissue. These findings suggest that atopic xenograft of YD-10Bmod cell line in nude mice has a improved productivity of tumors, produced tumors showed the characteristics feature of human tumor and invasive growth to surrounding tissue in histopathologic appearance. These atopic nude mouse model of tongue carcinoma might assist in studying oral cancer biology and effective choice of chemotherapeutic agents.
Abstract
The purpose of this epidemiologic study was to provide clinically useful information on the fundamentals for both the diagnosis and treatment planning of oral squamous cell carcinoma, which comprises 80~90% of all oral cancers. One hundred and forty two patients diagnosed with oral squamous cell carcinoma were selected from a total of 220 patients with oral malignancies. The patients’medical and follow-up records were reviewed and their survival was traced. The highest occurrence rate was observed in those aged between 60 and 69 years. The tongue was the most common primary site (31.7%) for oral squamous cell carcinoma. The survival rate was calculated using the Kaplan-Meier method. The overall five-year survival rate of oral squamous cell carcinoma patients was 66.90%. The 5-year survival rate according to stage was 85.82% for stage I, and 49.98% for stage IV. The five-year survival rate according to the originating site was 91.67% for the retromolar trigone, 75.30% for the tongue, and 62.41% for the maxillary gingiva. In terms of cell differentiation, the majority (58.5%) was the well-differentiated type, which had a 5-year survival rate of 70.62%.
Abstract
Purpose: The purpose of this study is to investigate the clinical and histological features of odontogenic keratocyst Patients and Methods: A retrosective review of 100 patients who were diagnosed as odontogenic keratocyst by hitological findings during the period of January 2000 and December 2005 in the Dept. of Oral and Maxillofacial surgery Pusan National University was consecuted. For each patient, age, sex, location of lesion, initial diagnosis by radiographic features, treatment procedure, hitologic findings and recurrance rate were evaluated. Results: In this study, OKC has male prevalance to female by 1.38:1, and most likely occurs during third decade. The most common site of lesion was mandibular ramus region(34.6%) and the most common symptom was swelling(50%). The most common initial diagnosis by radiographic findings was OKC and cyst enucleation was the most common treatment method. The recurrance rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. Conclusion: In this study, total recurrence rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. But, since 97% of patients were treated by enucleation and adjuntive excision, further styudy is need about concordance of recurrence rate with surgical method.
Abstract
Purpose: As the interest and demand for esthetics grow up with medical development, the number of patients who want to correct dentofacial deformities by orthognathic surgery has increased. And the success of orthognathic surgery is dependent upon satisfaction of patients in great measure. Therefore the purpose of this study is to examine functional disability, sensory disturbance and esthetic satisfaction of the patients after orthognathic surgery. Material and methods: Among 89 patients who orthognathic surgery was performed at Seoul National University Bundang Hospital during the period from July 2003 to July 2008, 46 patients were considered in the study. Patients were surveyed with questionnaires and visual analogue scale(VAS) which author has designed. The analysis and comparison were performed according to gender, follow up span, and type of surgery based on answer of questionnaires. Results and conclusions: Total satisfaction rate was 76%. And there was statistical significant difference between subjective evaluation of facial esthetics before the surgery and that of after surgery(p<0.05). Differences in occurrence of functional disability, sensory disturbance between groups were not observed. In conclusion, the operator should understand the postoperative self-satisfaction of the patients and complications. If we can communicate with the patients before operation. patients’satisfaction rate will increase after operation.
Abstract
Background: The vascularity of the peri-implant tissue is a very important parameter in establishment and maintenance of a healthy tissue after dental implant insertion. Objective: The purpose of this study was to compare the vascularity of the peri-implant mucosa between flap and flapless implant surgeries by using a canine mandible model. Study Design: In six mongrel dogs, bilateral, edentulated, flat alveolar ridges were created in the mandible. After 3 months of healing, two implants were placed in each side by either the flap or flapless procedures. After another healing period of 3 months, biopsies were obtained, prepared for light microscopy and exposed to morphometric measurements. Results: The supracrestal connective tissue lateral to the implant was found to be more richly vascularized in the flapless group than in the flap group. Conclusion: These results suggest that the flapless procedure may have an effect on increasing the vascularity of the peri-implant mucosa.
Abstract
and osteoporosis. Although, underlying pathophysiological mechanisms remain unclear, it seems that bisphosphonates inhibit osteoclast precursor cells, modulate migratory and adhesive characteristics and induce apoptosis of osteoclasts. Furthermore impacts on angiogenesis, microenvironment and signal transduction between osteoclasts and osteoblasts. In this report, we present a case of oral bisphosphonates induced osteonecrosis of the mandible in a 84-year-old patient who received for two years. Two tapered screw vent implants(Zimmer, USA) were placed in the area of first and second molar. Two weeks later after crowns restored, some inflammatory signs and symptoms were observed on the second molar area. Sequestrum was formed and the sequestrum was removed with the implant. Frequent follow-up checks and oral hygiene maintenances were done and the first molar implant was restored. There is insufficient evidence suggests that duration of oral bisphosphonate therapy correlates with the development and severity of osteonecrosis. Therefore, dentists should not overlook the possibility of development of bisphosphonate induced osteonecrosis in patients who have taken oral forms of medication for less than three years.
Abstract
Extracellular matrix (ECM) is known to function as a reservoir of endogenous growth factors, can be an effective delivery system of growth factor that easily lost bioactivity in solution. Fibrillar collagens like type I collagen, are the major constituent of the ECM and structural protein of bone. Also, it can be a scaffold for osteoblast migration. The purpose of this study was to compare the effects of absorbable Atelo-collagen Sponge(Teruplug®) insertion in tooth extraction sites on periodontal healing of the mandibular second molar after the extraction of the impacted third molar. The study population comprised 31 cases who had been scheduled for surgical removal of impacted mandibular third molars. All patients were in good general health and were not using any medication that would influence wound healing after surgery. In 15 cases control group, none was inserted into the tooth extraction site. In 16 cases experimental groups, Teruplug® was inserted into the tooth extraction site. We evaluated tooth mobility, pocket depth, gingival margin level preoperatively and 1 week, 2 weeks, 4 weeks, and 3 months postoperatively. The change was compared with two groups using Mann-Whitney test. The results were as follows. 1. There was no significant change of tooth mobility on both groups. 2. There was tendency of decreasing of previous pocket depth causing tooth extraction on both groups. 3. On gingival margin level, there was various change according to initial swelling and loss of attachment on both groups. 4. There was tendency of decreasing of gingival margin level on both groups because of removal of inflammation and decreasing of previous pocket depth. 5. There was large change of pocket depth on buccal middle, distal, lingual distal area because of tooth extraction and bone reduction. Compared with the control group and experimental group, we observed significant difference during some periods. The results of this study suggest that absorbable atelo-collagen sponge (Teruplug®) is relatively favorable bone void filler with prevention of tissue collapse, food packing and enhance periodontal healing.
Abstract
The concept of biostimulation of wounds by low-level laser therapy (LLLT) is attracting considerable attention. Although its effect on whole tissues has been studied quite extensively, the biological and cellular mechanisms underlying LLLT have not been clarified. In an experimental radius fracture in rabbits, Tang and Chai reported that LLLT enhanced the activity of red blood cells, macrophages, fibroblasts, chondrocytes, and osteoclasts within the fracture area. The purpose of the present study was to evaluate the effect of LLLT with a GaAlAs diode laser device on bone healing in rabbit mandibular fractures. We use 12 rabbits for this study. All rabbits were fractured mandible angle area using saw in anesthetic condition. In control group(n=6), none treatment was performed at fracture site. In experimental group(n=6), LLLT with a GaAlAs diode laser was radiated at fracture site daily for 7 days. All rabbits were sacrificed at 6 weeks later from performed fracture day. We studied the immunohistochemical staining of CD34 and Vimentin and the histochemical analysis for calcium and phosphorus content. The results were as follows. 1. In the histological and immunohistological staining, after 6week, fibroblasts, osteogenic cells and collgen fibers were observed more in experimental group than in control group. 2. In the histochemical analysis, the amount of calcium and phosphorus contents of the experimental group were more than the control group. From the results obtained, we suggest that the bone healing is stimulated by low-level laser irradiation in bone fractures.
Abstract
For many years, intermaxillary fixation using arch bar has been operated in treatment of mandibular fracture patients. But it has many complications including injury of operators and assistants cause by wire, inflammation of periodontium. For that reasons alternatives are required; osteosynthesis technique using mini plate, intermaxillary fixation using IMF screws have been available. Treatment by arch bar fixation, however, is still valuable to treat craniomaxillary fracture patients. The purpose of this study is to know effect arch bar on periodontium and influence gingival gel on periodontium applied by arch bar. 40 mandibular fracture patients are monitored. 30 patients were applied by arch bar, 10 patients were not. And the former were classified by 3 categories; Nano vitamin and Mastic gel were applied to 10 patients respectively and any gingival gel was not used to 10 patients. Clinical attachment level, bleeding on probing and periodontal depth of each group were measured and compared before operation and on 2 weeks and 6 weeks after operation. Mann-Whitney U test was used to analyze result which leads to this conclusion. 1. Whether arch bar is applied or not, treatment of mandlbular fracture gave rise to gingivitis, but 6 weeks after operation, gingivitis is restored to the same level as the state before operation. 2. More severe gingivitis appeared when arch bar is applied to mandibular fracture than when it is not. 3. Both gingival gel used in this study can reduce gingivitis which can be caused by arch bar. 4. In this study, Mastic gel is more effective for prevent gingival inflammation cause by arch bar than nano vitamin. In regard to this result, gingivitis is considered to be available because it is reversible and does not induce periodontal disease. Gingival gel is regarded to be helpful for patients applied by arch bar to feel less discomfort.