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Get PDFObstructive sleep apnea syndrome (OSAS) is a group of disorders in which breathing stops intermittently and repeatedly for 10 seconds or more during sleep. The causal site of the disorders is thought to be in the upper airway above the glottis. In order to understand the three-dimensional features of the oral and peripharyngeal structures involved in the disorders, we calculated the tongue volume/oral cavity volume ratio (TV/OCVratio) in the oral cavity using magnetic resonance imaging (MRI) for both OSAS patients and normal controls. The study subjects comprised 20 male patients with OSAS (apnea—hypopnea index [AHI]≧5.0, with a diagnosis of OSAS) and 20 normal male adults (AHI<5.0, with no history of OSAS) as the controls. We performed MRI to acquire T1- and T2-weighted images. We estimated tongue volumes on the basis of the cross-sectional area of each image, then using the tongue volume data, we calculated TV/OCV ratios. In the normal control group, mean (±SD) body mass index (BMI) was 21.68±1.73 and the mean TV/OCV ratio was 86.98± 3.16%, whereas these values were 25.0±15.94 and 90.56±2.15%, respectively, in the OSAS patient group. The TV/OCV ratio of the OSAS patient group was significantly higher than that of the normal control group (p<0.01).departmental bulletin pape
Get PDFTo investigate the origin and postnatal changes of mouse mandibular angular cartilage, in situ hybridization for cartilaginous marker proteins, histochemistry for alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP), and bromodeoxyuridine (BrDU) analyses were performed. Chondrocytes of the mandibular angular cartilage were derived from ALP-positive progenitor cells and first detected at embryonic day (E) 15.5. Newly formed chondrocytes rapidly differentiated into hypertrophic chondrocytes and hypertrophic cell zone rapidly extended in subsequent a few days. During this period, bone sialoprotein mRNA was more widely expressed than osteopontin mRNA in cartilage. Endochondral bone formation started at E 17.5 with the resorption of the bone collar by osteoclasts. These characteristics were consistent with those of the condylar cartilage, although developmental process was 0.5-1.5 day delayed relative to the condylar cartilage. During the postnatal period, contrast to the condylar cartilage, the angular cartilage constantly decreased in volume with advancing age. Reduction of proliferating activity estimated by BrDU incorporation accounts for this phenomenon. We demonstrate new structural features of the mandibular angular cartilage that may contribute to a coming research for the secondary cartilage.departmental bulletin pape
Get PDFHypersensitivity pneumonitis (HP) is an immunologically-mediated lung disease caused by repeated inhalation of dispersed antigen. Various cytokines have been reported to be involved in the immunopathogenesis of HP. Recently, some reports suggested an association between the genetic control of cytokine production and disease susceptibility. To evaluate whether cytokine gene polymorphisms are associated with HP, we performed a case-control association study involving 61 patients with HP, consisting of summer-type HP (SHP) and bird fancier's lung (BFL, also named bird fancier's disease), as well as 101 healthy controls. Polymorphisms of the genes for tumor necrosis factor (TNF)-α (－ 308G/A, －857C/T, －863C/A, －1031T/C), interleukin (IL)-10 (－592C/A, －819C/T, －1082G/A), transforming growth factor (TGF)-β1 (－509C/T, ＋869T/C), and IL-6 (－634C/G) were examined by restriction fragment length polymorphism analysis. There were no significant differences in allele frequency and genotype distribution among control, SHP, and BFL group. When HP group was divided into acute or chronic, no significant differences were detected between any groups. LPS-stimulated IL-6 secretion by whole blood cells was similar between subjects with GG genotype and non-GG genotype in IL-6－634C/G polymorphism.In conclusion, the association between HP susceptibilityand cytokine polymorphisms studiedwas not demonstrated.departmental bulletin pape
Get PDFMany different factors are known to cause and perpetuate the symptoms of temporomandibular disorders (TMD). However, the roles of parafunctional factors have not been clearly elucidated. We found one of these habits in the clinical setting. This parafunctional habit involves daily light touching of the upper and lower teeth, when the mouth is closed. We named this habit Teeth Contacting Habit (TCH). [Objectives] To investigate the following hypotheses: 1) TCH is associated with perpetuation of chronic pain of TMD patients; 2) TCH is associated with other behavioral factors. [Methods] Two hundred and twenty-nine TMD outpatients with chronic pain were analyzed with multivariate logistic regression models. [Results] TCH was found in 52.4% of patients. Patients with TCH and pain lasting for more than four months were less likely to experience improvements in pain at the first visit (OR = 1.944, p = 0.043). Other factors associated with TCH were as follows: unilateral chewing (OR = 2.802) and involvement in a precision job (OR = 2.195). [Conclusion] TCH can prolong TMD pain and is associated with other behavioral factors.departmental bulletin pape
Get PDFThe importance of masticatory muscle function on the growth and differentiation of condyle was examined. The aim of this study was to investigate how reduced masticatory muscle function influences intrinsic regulatory factors which govern growth and differentiation of condylar cartilage. Masseter muscles of 3-week-old Wistar rats were resected bilaterally. Masseteric resected animals and corresponding control animals were sacrifice dat 3, 6, 12 and 21 days post-resection. The condyles were then processed for histological and immunohistochemical analysis. The expression patterns of an inhibitory regulator (IL-1β) and a master regulator (Sox9) of chondrogenesis in condylar cartilage of growing rats were investigated. Quantitative analysis shows that masseteric resection significantly increased the number of IL-1β positive cells in proliferative layer. In contrast ,the number of Sox9 positive cells was significantly decreased compared to the control animals. It can be concluded that the reduced articular function due to masseteric resection decreased condylar cartilage cell differentiation which led to the decrease in the thickness of condylar cartilage.departmental bulletin pape
Get PDFCD83 has been known for a decade to be one of the best markers for mature dendritic cells (DCs). The recognition of CD83 was greatly changed since CD83 in thymus was unveiled to be essential for the generation of CD4+ T cells by the study using CD83-deficient mice. It was recently shown that both activated DCs and B cells release soluble form of CD83 and that low levels of soluble CD83 are present in normal human sera. Both in vivo and in vitro studies demonstrated that soluble CD83 has immunosuppressive roles such as the inhibition of DC-mediated T cell stimulation and the maturation of DCs. CD83 appears to have regulatory functions for immune response in light of observations that the soluble form of CD83 can inhibits immune reactions while being strongly up-regulated during DC maturation and activation. In addition, the fact that various cell types including thymic epithelial cells, activated T and B cells and activated DCs express CD83 suggests the universal role in immune function. Because of these immuno-regulatory functions, the therapeutic application of CD83 is highly anticipated in many pathological states including malignancy and autoimmune disease.departmental bulletin pape
Get PDFThe influence of number of autoclave treatment cycles (N) on rotational speed and total indicated run-out of commercially available air-turbine handpieces from five manufacturers was investigated at N=0, 50, 100, 150, 200, 250 and 300 cycles, and the significance in the test results was assessed by Dunnett's multiple comparison test. Some air-turbine handpieces showed the significant differences in rotational speed at N=300 cycles, however, the decreases of the rotational speeds were only 1 to 3.5 percent. Some air-turbine handpieces showed the significant differences in total indicated run-out, however, the respective values were smaller than that at N=0 cycle. Accordingly, it can be considered that the ball bearing in the air-turbine handpieces is not affected significantly by autoclave. To further evaluate rotational performance, this study focused on the rotational vibration of the ball bearing components of the air-turbine, as measured by Fast Fourier Transform (FFT) analysis; the power spectra of frequency of the ball's revolution, frequency of the cage's rotation and frequency of the ball's rotation were comparatively investigated at N=0, 150 and 300 cycles, and the influence of autoclave was evaluated qualitatively. No abnormalities in the ball bearings were recognized.departmental bulletin pape
Get PDFThe aim of the present study was to investigate the extent to which oral streptococci or lactic acid producing bacteria are able to regulate pH value, especially at low pH values associated with dentinal carious activity using a PCR method. One millimeter-thick sections were sliced from 24 extracted carious human molars. The pH values on the tooth sections were evaluated using a pH-imaging microscope. A dentin sample (1×1×1mm) was prepared from the areas with the lowest or highest pH and homogenized to extract bacterial genomic DNA. Specific primers were used for nested PCR to mutans streptococci (MS: Streptococcus mutans and Streptococcus sobrinus). Conserved primers were also used for PCR to lactobacilli and gram positive bacteria. The PCR products were separated by electrophoresis, and then oral bacteria were identified. There was no significant difference between carious and intact dentin in MS identification. However, the frequency of the product amplified by the conserved primers in carious dentin (16/24, 66.7%) was significantly higher than that in intact dentin (2/24, 8.3%), and PCR products demonstrated, by sequence analysis, various bacteria, including oral streptococci. It was concluded that oral streptococci may be associated with the development of "low pH-carious dentin".departmental bulletin pape
Get PDFObjectives: The aim of this study was to compare the oral health status of migrants to Japan with that of Japanese using the questionnaire and the Oral Health Status Index (OHSI). Methods: The questionnaire for collecting demographic and behavioral variables and the OHSI were applied in a mixed migrant/Japanese sample of patients from a dental clinic in Yokohama. A sample of 224 subjects, 52% of whom were migrants, was selected from new patients. Results: The mean OHSI scores were 78.56 for migrants and 83.16 for Japanese (p<0.01). Multiple regression analysis of OHSI showed that the statistically significant contributors were: age, status (migrants / Japanese), reason for initial visit, perceived oral health, and flossing behavior. Conclusion: The oral health status of migrants was worse than that of Japanese even though they were younger than Japanese. The present public support system for foreign patients and their self-care behavior were considered to be the factors for the inequity in oral health status.departmental bulletin pape
Get PDFIn the present study, water was circulated in a simulated dental unit water line with electrifying a small current. The morphology of the biofilm developed on inner surface of the water line and the number of heterotrophic bacteria were investigated to elucidate the effect of a low level electric current on the biofilms formation associated with bacteria reproduction. Destruction and malconformation of biofilms by electrification was observed using SEM, in addition to deformation and hypertrophy of the bacteria. By naked eye observation, small pieces, which were possibly exfoliated biofilms, were detected in electrified water. While an adherent, yellow gel was demonstrated on the inner surface of the water line without electrification. With electrification, the number of bacteria decreased during the first week, however the bacteria increased gradually after that. The number of bacteria without electrification was consistently greater than that with electrification and the difference was statistically significant (P<0.05). The predominant bacteria were identified as Sphingomonas paucimobilis. The excess chlorine levels decreased to a minimum value within one week. The small current appeared to have effects on biofilm formation of heterotrophic bacteria that resulted in enhanced chlorine sterilization of dental unit water. Thus, electrification has considerable potential for the extermination of bacterial biofilms in dental unit water lines.departmental bulletin pape