"The present study aimed to verify the effects of DFO on PDL cells, with particular emphasis on focusing on osteoblastic differentiation. Its mechanisms related to heme oxygenase-1 (HO-1) pathway were also analyzed. DFO increased the expression of HO-1 and early osteoblastic differentiation markers, such as alkaline phosphatase (ALP) and bone sialoprotein (BSP). DFO upregulated heme oxygenase-1. Treatment with HO-1 siRNA blocked the DFO-stimulated osteoblastic differentiation and HO-1 expression. The NF-kB inhibitor pyrrolidine dithiocarbamate, phosphatidylinositol 3-kinase inhibitor Wortmannin, and p38 MAPK inhibitor U0126 blocked the effects of DFO on HO-1 expression and osteoblastic differentiation in PDL cells. Collectively, these data suggest that DFO promotes osteoblastic differentiation and induces the expression of defense protein HO-1 probably via PI3K, p38 MAPK, and NF-kB signalling pathways in PDL cells."

"Photodynamic therapy(PDT) is recently developed as an effective treatment for malignant disease. Carboplatin, a less nephrotoxic analog of cisplatin, has been widely used for the treatment of multiple malignancies. In this study, we investigated the cytotoxic and apoptotic effect of combined modality of photofrin mediated PDT with cisplatin and carboplatin on KB cell human oral cancer cell line in vitro. The attached KB cells were incubated with cisplatin(0.04mg/ml) and carboplatin(0.02mg/ml) for 24h at 37℃ and followed by photosensitization with photofrin for 6h and laser irradiation with 630nm LED at an intensity of 2.0 J/cm2 for activating photofrin for 15min. Then MTT assay and SYTO 16 green & Propidium iodide (PI) double staining were used respectively to measure the cytotoxicity and nuclear morphology at 24h after PDT.This study demonstrates that the combined modality with carbopaltin resulted in enhanced apoptotic cell death as well as cytotoxic effect on KB cells in vitro, which suggests the feasibility of combined modality and the possibility of reducing the effective dosage of photofrin and carboplatin and lowering the side effects on normal cells."

"Currently, dental implants are generally used for reconstruction of oromaxillofacial defects. Implants are widely used in dental and medical fields. The materials of implants are variable such as metals and ceramics. The materials of implants must be have not toxicity and biocompatibility to host and mechanical(physical) strength. Bones must be attached to titanium surface without any other tissues. many researcher's had studied for raising the osseointegration through various method which are including implants designs and materials. It was reported over 95% success ratio. many researcher's study the methods which are enhancing the speed of bone remodelling and osseointegration. Thermo dynamic therapy is one of the method to accelerlate the speed of bone remodelling and osseointegration. Thus it raise stability of implants. The purpose of this study was to evaluate the effect of diode laser irradiation for ossoeintegration in implant interface and between the implants threads. 24 New Zealand white rabbits which were about 3kg weight, used for experiment. 2 implant's were implanted every rabbit's tibia. 2 weeks, 4 weeks, 8 weeks after implantation, tissue sample were removed from sacrificed rabbit's tibia. 8 rabbit's were sacrificed every 2, 4, 8 weeks and undecalcified sample were made from tissue sample. We have investigated the undecalcified samples by back scattered electron microscope. We have analysied the length rate and area rate in implant interface and inside the threads. The results were as follows. 2 weeks, 4 weeks, 8 weeks experimental groups which were irradiated low level laser therapy showed rapid bone remodelling than control groups. It was suggested that Initial bone remodelling may be effected by LLLT because of implant bone contact ratio between 4th weeks and 8th weeks had no siginifant difference. Initial bone remodelling may be more influenced than later bone remodelling by LLLT because of new bone formation area ratio between implant threads had no significant differences during 4th to 8th weeks. According to above results, low level laser irradiation accerlate the new bone formation in implant interface and inside the implants threads at initial stage. there were many factors which are increasing the bone remodelling, because there were many differences between experimental and control groups. Low level laser irradiation were helpful for increasing the initial stage of bone remodelling because of above results."

"The incidence of multidrug-resistant strains of Staphylococcus aureus continues to increase in hospitals and the community all over the world. As the importance of miner surgery in dentistry gets greater recently, the frequency in use of antibiotics has been increasing. Although several cases of acquired infection in oral cavity in dental hospital has been reported, the research on isolation of S. aureus and evaluation of its antibiotic resistance from outpatients in the dental clinic has not been found yet. The aim of this study was to evaluate the antimicrobial resistance of S. aureus isolates. The isolation rate of S. aureus were 41.7% in dental hospital personnel, 60.4% in outpatients and 62% in dental hygiene students. S. aureus which showed resistance to penicillin were 88.6%, ampicillin 88.6%, erythromycin 8.6%, tetracycline 4.3%, oxacillin 4.3%, cefoteten 4.3%. Six strains of S. aureus showed the susceptible to all antibiotics tested. Sixty-four(91.4%) strains were multiple antibiotic resistance. Fifty-two strains(72.8%) resisted to AM-P. and Seven strains(10.0%) resisted to AM-P-E, AM-P-GM, AM-P-TE."

"Diabetic patients tend to exhibit delayed bone formation and osteoblast differentiation, which results in osteopenia. Recently, numerous clinical reports suggest that 635-nm light irradiation improves bone regeneration and wound healing, and reduces pain in patients suffering from diabetes.The purpose of the present study was to test the hypothesis that 635-nm irradiation can influence bone formation by MC3T3-E1 osteoblasts cultured on high concentrations of glucose(25mmol/L D-glucose) in the presence or absence of phorbol 12-myristate 13-acetate(PMA), and to establish an in vitro pathological model of bone formation.The effect of 635-nm irradiation on bone formation was investigated using Alizarin Red S staining, and alkaline phosphatase enzyme activity and calcium deposition assays. In addition, gene expression of the osteogenic markers BMP-2, osterix and osteocalcin were assayed by RT-PCR.Calcium deposition by MC3T3-E1 cells was reduced in the presence of high concentrations of glucose or by PMA supplementation. However, 635-nm irradiation led to an increase in calcium deposition by MC3T3 cells, followed by increased bone mineralization. mRNA expression of BMP-2 and osterix at an early stage and of osteocalcin at a late stage was significantly upregulated by 635-nm irradiation in MC3T3-E1 cells supplemented with high concentrations of glucose. Irradiation at 635 nm increases bone mineralization in MC3T3-E1 cells cultured in vitro on high concentrations of glucose and alters osteogenic gene expression, which accelerates bone formation in hyperglycemic conditions."

"Cyclosporin A(CsA) as immunosuppressive drug is used to prevent immune reactions after organ transplant. And also It is reported that the effect of CsA on osteoblast differentiation has been controversial according to dosage. The purpose of this study was to examine the effect of various CsA concentrations on osteoblast differentiation. According to different concentration of CsA, growth curve, apoptosis index MTT assay, ALP activation and osteocalcin secretion, in cultured NHost were analyzed. Treating osteoblasts with low concentrations of CsA increased growth rate, MTT assay activity, ALP activation and osteocalcin protein levels in a dose-dependent manner, while high concentration showed opposite results. Therefore, these results showed that low concentrations of CsA increased osteoblast differentiation, while high concentrations elicited an opposite response, showing inhibition of CsA on osteoblast differentiation. It suggested that different CsA concentrations might play in regulating NHost differentiation, and its specific activation of lower concentration will represent a viable anabolic therapy for bone resorption disease in future."

"Emodin is a bioactive compound isolated from the root and rhizomes of Rheum plamatum L. (polygenaceae), which is known as a traditional Chinese and Japanese medicine. In the present study, the effect of emodin on YD-15 mucoepidermoid carcinoma cells and its molecular mechanism were investigated. This study shows that emodin significantly inhibits the growth of YD-15 cells. Activation of caspase-3 and PARP is triggered by emodin and it increases sub-G1 population and the number of YD-15 cells with nuclear condensation and fragmentation. In addition, we found that emodin significantly decreases myeloid cell leukemia 1(MCL-1). These results suggest that MCl-1 is an important molecule for emodin-induced apoptosis. Taken together, emodin inhibits cell viability and induces apoptosis via down-regulation of MCL-1 and it can be a new potent anticancer drug candidate for the treatment of mucoepidermoid carcinoma."

"Malignant tumor cells outgrow new blood vessel formation and tend to be in hypoxic state. Hypoxic cancer cells adapt to hypoxic conditions by transforming its characteristics. On the other hand, one of the most important features of cancer cells is that carcinoma cells loses its inherent epithelial phenotype and acquires mesenchymal characteristics, called as epithelial-mesenchymal transition(EMT). It has been already well known that EMT contributes to tumor invasion and metastasis.The present study investigated whether hypoxia play a major role in induction of phenotypic changes of oral squamous cell carcinoma(OSCC). Furthermore, the mechanism of EMT in oral squamous cell carcinoma cells by hypoxia has been clarified.To mimic hypoxic condition, cobalt chloride and desferoxamine, well-known hypoxic mimetic agents, were used. This study shows that hypoxia suppresses the expression of E-cadherin(epithelial marker) and increases vimentin and N-cadherin(mesenchymal markers) in OSCC. In addition, α5 integrin protein, which is a receptor for fibronectin and an important molecule for tumor invasion, is prominently induced by hypoxia."

 Osteogenic sarcoma is primary malignant bone tumor. It can arise de novo or from the benign precursors lesions, likePaget’s disease, giant cell tumor, chronic osteomyelitis, osteoblastoma, and fibrous dysplasia. Here, we present a case ofosteogenic sarcoma arising from florid osseous dysplasia appearing as a rapidly growing bony bulging mass in 44‐year‐oldKorean female who had at first been non‐symptomatic, but later suffered from the numbness of chin and lower lip. Theradiologic images revealed the mixed radiopaque‐ radiolucent intraosseous lesions throughout the mandible, which werediagnosed as florid osseous dysplasia pathologically. But only after 6 months, the lesions were substituted by the radiologicalill‐defined diffuse bony sclerotic lesion with bone destruction, accompanying the interrupted periosteal bone formation,which were pathologically diagnosed as osteogenic sarcomas. These serial clinicopathologic changes imply themalignant progression of florid osseous dysplasia rather than the collision of benign condition, florid osseous dysplasiaand malignant tumor, osteogenic sarcoma. The possibility for fibro‐osseous lesion of the jaw as premalignant lesionshould not be overlooked; therefore, periodic check‐ups for the lesions are necessary. Proper evaluation and interpretationfor clinical neural symptom and radiologic change of bone density may lead to the correct differential diagnosisand therapeutic intervention.

 This infection includes an allergic bronchial reaction, an aspergilloma, and an invasive aspergillosis, which is morecommon in immunosuppressed patients and presents as multiorgan disease. The maxillary sinus is a relatively commonsite for formation of an aspergilloma where it forms around a nexus of foreign body. It has been indicated that the foreignbody containing zinc extruded into the maxillary sinus has the potential to become infected and form anaspergilloma. The treatment of this disease is radical surgery and adjunctive systemic antifungal therapy. This is a casereport of solitary aspergillosis of the right maxillary sinus. We experienced a case of right maxillary sinus aspergillosisin a 37 years old male who has dull pain on right temporal and zygoma area. We reported a case with review of literature.

 Currently, Low-level laser therapy (LLLT) is widely used in medicine and dentistry. It has been suggested that LLLTmay be beneficial in management of many different medical conditions, including pain, wound healing and nerve injury.Stimulation with LLLT can enhance bone repair as reported in experimental studies on bone defects and fracture healingalso. As far as hard tissue is concerned, the biostimulating effect of laser has been demonstrated more rapid healing oftibial bone fracture in mice. This study was performed to compare new bone formation between with LLLT and withoutLLLT. Two cylinder implants(5mm diameter, 5mm length) were implanted on rabbit's tibia. LLLT was done to one implantwith 632mm diode laser. And than Rabbit's were sacrificed after 2nd, 4th, 6th, 8th weeks after implantation. Bone withimplant were removed and fixed with 10% formaline. Undecalfied sample were prepared after spurr low resin embedding.Sample were grind and polished to 100㎛. The results were as follows. The amount of trabeclue of experimental groupwere superior to that of control group from 2 weeks to 8 weeks. There were no difference in arrangement of trabeculebetween two groups. Bone implant contact were significantly increased at 4th weeks in experimental group. The numberof ostecytes in trabecule were different at 4th weeks experimental group. Osteone were appeared dominantly at 6thweeks experimental group, while at 8th weeks experimental group were superior than control group. LLLT group showedincreased amount of trabecule, bone implant contact, number of osteocytes & osteone. It suggested that LLLT might beincrease the bone formation rate and accelerate the bone formation time.

 The aim of this study is to find out histomorphologic change and cellular activity of condyle resulted from unilateralmastication by comparison of cell proliferation and apoptosis activity. 30 adult rats were dived to 15 experimental groupand 15 control group randomly. Right upper and l ower molars were gently extracted in experimental group, to makeunilateral mastication environment. All subjects were sacrificed at 1 week, 2 weeks and 4 weeks by chloroform, and theirtissues were prepare to observation. Streptovidin-biotin system for BrdU stanning, was used to determine cellular proliferativeactivity. TUNEL method was used to determine apoptotic activity. The result for cellular activity was recordedat both of anterior portion and posterior portion of condyle. Hematoxylin and Eosin stanning was used for histiomorphologicalchange. The results were as follows. There were more change in superficial layer than deep layer of condylein cellular activity. In anterior portion of condyle cartilage, cellular proliferative activity of experimental group was lowerthan control group and apoptotic activity of experimental group was higher than control group. And apoptotic activity ofextracted side in experimental group is the most. In posterior portion of condyle cartilage, cellular proliferative activity ofextracted side in experimental group was higher than non-extracted side and control group, And apoptotic activity of extractedside in experimental group was the low. As a result of histomorphological change, there was hyperplasia in posterior regiono f extracted side c ondyle i n experimental g roup, but t here was n o change i n unextracted side i n experimentalgroup. There was histomorphological hyperplasia in posterior condyle of experimental group as results of high cellularproliferative activity. There was mainly apoptotic change of anterior portion condyle in experimental group. But therewas no histomorphologic change. In other words, there was hyperplasia by increasing of cellular proliferative activity inposterior portion of nonfunctional side condyle. In functional side condyle, there was no histomorphological change infunctional condyle, but there was change in cellular activity.