In rural areas of developing countries, rapid aging and reduced life expectancy have been observed, and it has been hypothesized that excess oxidative stress is one cause of rapid aging. Oral disease may contribute to one of the risk factors in the production of oxidative stress. The purpose of this study was to examine the influence of oral disease on oxidative stress in the rural Cambodian population. Eighty-seven subjects living in the rural area in Mondulkiri Province, Cambodia were examined as a target group, and data were obtained regarding caries experience, probing pocket depth (PD), and bleeding on probing (BOP). The level of oxidative stress was evaluated by the diacron reactive oxygen metabolites (d-ROMs) test. The results revealed that the level of d-ROMs correlated with their age, the number of healthy teeth (HT), the number of missing teeth (MT), the decayed, missing and filled teeth (DMFT) index, the number of present teeth (PT), the rate of≥4mm PD, and the BOP rate. In stepwise multiple regression analysis, the BOP rate was the most influential parameter linking to the production of oxidative stress as an independent variable. HT was secondary, followed by the number of filled teeth (FT). A control group, 30 residents of Phnom Penh City within an urban environment, was compared with the target group. The target group had significantly higher levels of oxidative stress, caries experience,periodontal status, and diastolic blood pressure (BP). The findings of this study indicate that periodontal disease may increase the production of oxidative stress, and the data obtained suggest that HT and FT contribute to the reduction of the level of oxidative stress.

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Basaloid squamous cell carcinoma(BSCC)of the gingiva other than the tongue or floor of the mouth is uncommon. We reported a case of an 85-year-old man who was diagnosed with stage IV BSCC in the gingiva. An excision of partial resection mandible was performed and a functional elective neck dissection was carried out. The patientʼs recovery was uneventful until contralateral local regional lymph node metastasis was revealed by PET-CT. Histopathologically, the tumor consisted of cords and nests of basaloid cells with a cribriform growth pattern. Large nests frequently exhibited central comedonecrosis. The proliferated atypical basal cells were arranged in a gland-like space and extended to the mandible bone. Additional findings included hyaline material deposition in the stromal tissue, and keratin pearls or squamous cell components were observed. Immunohistochemically, CK17 showed great positive expression in all layers of the tumor cells. The basal cell marker of p63 revealed a high immunopositive rate with more than 90%. Strong positive expression of Ki-67 and p53 suggested high proliferative and malignant activities, and laminin5γ2 showed a moderate to strong positive expression. Our results indicated that BSCC was an aggressive tumor and CK17 might be a useful marker in differential diagnosis.

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In this study, in order to clarify the host genetic factors that influence dental caries susceptibility, we examined the role of host genetic factors by comparing whole genome expression and salivary protein levels using C57BL/6 (B6) mice, which showed high dental caries susceptibility, and C3H and B6-Chr2^C3H mice, which show low dental caries susceptibility. We analyzed gene expression in the submandibular gland by genechip microarray using submandibular glands from B6, C3H and B6-Chr2^C3H mice. Two genes that showed the top expression in each category among the 3 strains were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and quantitative Real-Time PCR analyses. We also analyzed saliva protein concentration by the Bradford method. On microarray analysis, the Tmem87A and Capn3 genes showed the greatest differences in gene expression among the 3 strains. These genes were confirmed by RT-PCR and quantitative Real-Time PCR, and protein concentrations in C3H, B6-Chr2^C3H and B6 were 0.210μg/ml, 0.177μg/ml and 0.217μg/ml, respectively. Protein concentrations in B6-Chr2^C3H were significantly lower than in B6 and C3H. Thus, Tmem87A and Capn3 may be related to differences in caries susceptibility observed with the Substituted of chromosome 2 in mice. Moreover, protein levels in saliva do not affect caries susceptibility in 3 strains. This suggests that differences in caries sensitivity of B6, C3H and B6-Chr2^C3H are related to differences in water permeability in the salivary glands.

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Orthodontically induced inflammatory root resorption is a common complication associated with orthodontic tooth movement. The aim of this study was to investigate how T-helper (Th) 17 cells and interleukin (IL)-17 contribute to root resorption during orthodontic tooth movement. Fifteen male 8-week-old SKG/Jcl mice (rheumatoid arthritis (RA) group) and 15 male 8-week-old BALB/cAJcL mice (wild type group) were subjected to an excessive orthodontic force of 25 g to induce a mesially tipping movement of the upper first molars for nine days. The expression levels of the cathepsin K, IL-17, IL-17 receptor (IL-17R), receptor activator of nuclear factor kappa B (RANK) ligand (RANKL), and RANK proteins were determined in the resorbed lacunae of the mouse periodontal ligament (PDL) by an immunohistochemical analysis. Following the experimental tooth movement in vivo,resorption lacunae with multinucleated cells were observed in both groups. The immunoreactivities for cathepsin K, IL-17, IL-17R, RANKL, and RANK in the RA group were found to be significantly increased in the PDL tissue subjected to the orthodontic force on day 9 compared with the control group. The double-immunofluorescence analysis for IL-17/CD4 detected immunoreactivity in the PDL. The results of this study suggest that the Th17 cell response to excessive orthodontic force may lead to the progression of root resorption by increasing the expression of IL-17, RANKL, and RANK.

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Periodontal disease is one of the most prevalent chronic inflammation of oral cavity, and has been reported to be associated with atherosclerosis. In this study, we assessed the potential of orally or nasally administered recombinant HSP60 from Porphyromonas gingivalis (rGroEL) for prevention of atherosclerosis accelerated by P.gingivalis. Apolipoprotein E deficient spontaneously hyperlipidemic (Apoe^shl) mice were orally or nasally immunized with GroEL and then challenged intravenously with P.gingivalis 381. Atherosclerotic lesions in the proximal aorta of each animal were analyzed histomorphometrically, and the serum concentrations of rGroEL-specific antibodies and cytokines were determined. Although antibody titer sufficient for taking oral or nasal immunity of GroEL under adjuvant-free condition was not obtained, the antibody titers significantly rose by booster effect of P.gingivalis infection. Furthermore, mice given rGroEL orally or nasally followed by P.gingivalis-challenge possessed significant reduction of atherosclerotic plaque accumulation in aortic sinus and lowered the serum MCP-1 and ox-LDL levels compared to nonimmunized, P.gingivalis-challenged mice. These results suggest that oral or nasal immunization with rGroEL could be an effective vaccine for prevention of atherosclerosis accelerated by P.gingivalis.

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When dental pulp is subjected to chronic decay or mild external irritation such as dental attrition or abrasion, hard tissue formation is promoted and reparative dentin is formed. It has been reported that prostaglandin E2 (PGE₂) is able to enhance or inhibit this process,depending on its concentration, but the precise mechanisms are uncertain. Thus, in the present study, we simulated dental pulpitis by PGE₂ stimulation in human dental pulp cells (HDPC), and investigated the effects on Smad dynamics, as well as heat shock protein 70 (HSP70)and Matrix Gla Protein (MGP). HDPC were obtained from unerupted teeth extracted in the course of orthodontic treatment. HDPC were cultured and stimulated with various concentrations of PGE₂, after which totalRNA was extracted and stored at −80℃. Subsequently, mRNA was amplified by PCR and cDNA was synthesized by real-time PCR. Protein levels in lysates from cultured HDPC were assessed by SDS-PAGE and Western blotting. PGE₂ was found to increase HSP70 mRNA levels and decrease MGP mRNA levels in a concentration-dependent manner. Furthermore, phosphorylated-Smad 1/5/8 and Smad 6 levels were higher after PGE₂ treatment. These results indicate that PGE₂ enhances HSP70 mRNA expression in dentalpulp and decreases MGP mRNA expression. PGE₂ stimulation at 1μM also promotes the expression of Smad6, an Anti-Smad, thereby inhibiting Smad1/5/8 phosphorylation, blocking BMP signaling and inhibiting hard tissue formation.

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Propofol is an intravenous anesthetic agent widely used to introduce and maintain anesthesia during surgical procedures, and it has often been used in recent years as a sedative in patients with acute lung injury (ALI). A common cause of ALI is sepsis, and apoptosis in vascular endothelium and alveolar epithelial cells (AECs) during sepsis plays an important role in the pathologic formation of ALI. Propofol has drawn greater attention due to its anti-inflammatory effect and anti-apoptosis capability. It was already found that propofol inhibited MCP-1 mRNA expression and secretion, as well as the phosphorylation of p38 MAPK, SAPK/JNK, ATF-2, and c-Jun induced by lipopolysaccharide (LPS) in AECs. The present study investigated the effect and mechanism of propofol on apoptosis induced by hydrogen peroxide (H₂O₂) in AECs. AECs were treated with 0.1 or 1μMH₂O₂ for 1, 12,or 24h following pretreatment with 25μM propofol for 1h. The cell proliferation assay was performed using the TetraColor ONE. The percentage of apoptotic cells was measured by flow cytometry analysis. The phosphorylation of c-Jun and expression of Bim, Bcl-2, and Bcl-xL were measured by a Western blot analysis. Propofol down-regulated c-Jun phosphorylation and Bim (as a known c-Jun-mediated induction of pro-apoptotic and antiapoptotic target genes) expression and up-regulated the reduction of Bcl-2 and Bcl-xl expression induced by H₂O₂ in AECs. These results suggest that the application of propofol has potential to reduce apoptosis through the JNK pathway and Bim down-regulation.

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Its goals are to treat abnormalities of dentition and occlusion that develop during the growth period and to predict and thus prevent abnormalities in the permanent teeth of the adult phase by imparting dynamic occlusal guidance force in an early stage to establish healthy permanent occlusion. For this study, the authors sought to obtain a detailed picture of tooth movement when a superelastic Nickel-Titanium coil spring was applied. To achieve this, we conducted mechanical tests on Nickel-Titanium coil springs and Cobalt-Chromium coil springs with different coil wire diameters and coil outer diameters. Four kinds of coil spring were attached the space which formed by extraction of maxillary first premolar in dog. Root resorption accompanying molar tooth movement was compared Nickel-Titanium coil and Cobalt- Chromium coil based on micro-CT finding and histopathological findings in beagle dogs. In Nickel-Titanium spring, no permanent deformation was observed when compression was sufficient to bring the coils into contact. In contrast, with the Cobalt-Chromium spring,permanent deformation was recognized when compression was sufficient to bring the coils into contact. In the animal experiments at 80-g load, which is considered the optimum orthodontic force,bone resorption was seen on the pressure side and findings of new bone like tissue observed on the tension side. At occlusal guidance force of 240-g load, remarkable bone resorption and root resorption were seen in all of springs. Nickel-Titanium spring exhibited significantly greater root resorption than the Cobalt-Chromium spring. As these results show, when a Cobalt-Chromium spring is applied to 80-g load, the load decreased as the tooth moves, in the contrast no load decreased in Nickel-Titanium spring. Slight root resortion was seen in the case of 80-g load in Nickel-Titanium spring and CobaltChromium spring. In clinical practice, a great care is needed in the case of using Nickel-Titanium spring for dynamic occlusal guidance.

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Periodontitis is associated with an increased risk of atherosclerosis, and accumulating evidence suggests a positive association between anti-heat shock protein 60 autoantibodies and atherosclerosis in humans. Heat shock proteins of the GroEL or HSP60 class are highly conserved proteins essential to all living organisms. In this study, we examined the effects of immunization with recombinant HSP60 from Porphyromonas gingivalis on antibody responses and the development of atherosclerosis. Atherosclerosis was examined in BALB/c mice fed a high-fat diet or a regular chow diet following subcutaneous immunization with GroEL or intravenous injection with P. gingivalis. The proximal aorta lesion area, serum levels of anti-GroEL antibodies, CRP and MCP-1 levels, expression of HSPs, and inflammatory mediator expression in aorta were measured. Early atherosclerotic lesion area was substantially lower in HFD-fed mice immunized with GroEL compared to P.gingivalis-challenged mice, although significant atherosclerotic lesions, serum immunoglobulin G responses to GroEL, and HSP60 were detected in GroEL-immunized mice. Immunohistochemical staining confirmed strong HSP60 expression in the vascular wall of HFD-fed mice compared to RD-fed mice. Although immunization of the HFD-fed mice with GroEL slightly enhanced serum MCP-1 secretion as well as CD40/40L and LOX-1 expression in the aorta, it did not affect serum CRP levels. These results suggest that immune response cross-reactivity to bacterial HSPs, including periodontal pathogens, with arterial endothelial cells expressing HSP60 are not associated with atherosclerosis severity caused by P.gingivalis challenge. This may explain why antibody responses to bacterial HSPs are an unlikely major risk factor for coronary artery disease.

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We have previously shown that Foxp3⁺ CD4⁺ regulatory T (Foxp3⁺ Treg) cells are elevated in inflamed gingival tissues of mice infected with Porphylomonas gingivalis (P. gingivalis), a major periopathologic bacteria. Foxp3⁺ Treg cells play a crucial role in maintaining immune tolerance and homeostasis. In this study, we elucidated the mechanisms ofFoxp3⁺ Treg cell induction at sites ofinflamed gingival tissue. A murine periodontal disease model with alveolar bone loss was established by oral infection with 10⁹ cfu of P. gingivalis suspended in 0.1ml ofPBS with 2% carboxymethylcellulose, 15times over three weeks. Gingival mononuclear cells were isolated from mouse gingival tissues for analysis by kinetic observation. Elevated numbers ofCD11c⁺ dendritic cells (DCs) but low expression ofco-stimulatory (CD40, 80, 86) and MHC-II were detected in inflamed gingival tissues. Interestingly, significantly induction of IL-6 and TGF-β transcripts was detected in early stages ofthe inflammation period. Furthermore, expression levels ofTGF-βtranscripts were maintained through the end ofexperiment. Importantly, diminished levels ofIL-6 transcripts but significant induction ofretinal dehydrogenase 2 (RALDH2) transcripts, a major enzyme for retinoic acid synthesis, were detected in later stages of the inflammation period. These results suggest that inflammation-derived CD11c⁺ DCs regulate inflammation and induce Foxp3⁺ Treg cells in the gingiva ofthe mouse model.

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We performed torsional resistance tests to examine the Protaper Retreatment D1, D2 and D3 and the NRT-GPR 3N and 4N, which are Ni-Ti files used to remove gutta-percha in root canal retreatment. On cyclic fatigue failure tests, the D1 was the quickest to break, and the 4N took the longest to break. Torsional bending tests showed the fracture angle to be largest for the 4N, which was significantly different from that of all the other files (p< 0.01). There were no significant differences among the D1, D2 and D3. Torsional torque tests showed that the superelastic D1, that has the largest diameter, had the largest fracture torque. Files with larger diameters had higher fracture torques. On bending torque test, the D1 differed significantly from all the other files (p<0.01). Significant differences were also seen between different versions of the same file type (p<0.01). All of the fracture surfaces of files used in torsional resistance tests in the present experiment showed SEM findings that appear to be instantaneous breakage. The results of this experiment indicated that torsional resistance test values varied according to differences in file properties and shape. It may be necessary to consider these results when using files in clinical practice.

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Salivary gland atrophy is an important problem in clinical dentistry since salivary glands produce and secrete saliva that creates and regulates the environment of the oral cavity. To clarify mechanisms of salivary gland dysfunction, we have established a system for primary culture of parotid acinar cells. We have found that the process of cell isolation induced the stress signal mediated by Src and p38 MAP kinases, which causes the alteration in expression patterns of various differentiation markers. Claudin-4 began to be expressed after the cell isolation and increased during the culture while the original acinar cells do not express claudin-4. In addition, the expression of salivary acinar markers such as amylase and aquaporin-5 were rapidly decreased during the culture, which implies the dedifferentiation of acinar cells. In this study, we examined the effects of [6]-gingerol,which is an ingredient of ginger, on the dedifferentiation of parotid acinar cells. We found that the increase of expression level of claudin-4 mRNA during the culture was suppressed by addition of [6]-gingerol. The effect was confirmed by immunoblot analysis. In addition,the decrease of amylase and aquaporin-5 during the culture was also suppressed by [6] -gingerol. These results suggest that [6]-gingerol has a protective effect against the cellular stresses that induce dysfunction of salivary glands.

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Lipomas are the most common soft tissue tumors of mesenchymal origin. These tumors constitute about 20% of cases involving the head and neck region and 1-4% of those affecting the oral cavity, predominantly affecting the buccal mucosa, floor of mouth and tongue. Fibrolipoma is a rare histological variant of lipoma with a much lower incidence in the oral cavity. We report herein a case with large sublingual fibrolipoma along with a review of the literature for this tumor.

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