We did a follow-up investigation that examined changes over time in the oral environment of low caries risk patients after initial placement of removable prostheses. Denture and Dentate groups of aged subjects were followed up over time to track changes in their oral environment. Seven oral environment factors were selected that strongly correlate with caries risk, including unstimulated and stimulated salivary flow rate, unstimulated and stimulated salivary buffering capacity, and oral bacteria (mutans streptococci, lactobacilli and Candida). Wilcoxon's signed rank test revealed that there were significant changes, and that the number of lactobacilli increased one year after placement of the dentures in the Denture group. No changes were noted in any of the factors in the Dentate group. We concluded that placement of removable dentures changed low caries risk to high for the number of lactobacilli. Future investigations should be done on preventive measures against the caries-inducing effect of denture placement.

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Highly volatile organic compounds, such as volatile inhalation anesthetics, are commonly used in the operating room. This study investigated the absorption function of the organic gas absorption canister. An organic gas absorption canister was inserted between a ventilator and an artificial lung, sevoflurane or isoflurane was supplied from the ventilator, and the concentration of inhalation anesthetic that moved to the artificial lung side was measured. The breakthrough time became longer when the concentration of the anesthetic gases decreased : 1,234 min for sevoflurane and 1,325 min for isoflurane when the concentration was 103 ppm (0.103%). Comparison of the estimated weights of sevoflurane and isoflurane absorbed in the absorption canisters indicated that the absorption weight increased as the concentration decreased.

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Cone-beam computed tomography (CBCT) is not well equipped to provide readouts in CT number (CTN). We examined the correlation between the pixel density of CBCT images from two machines and CTN of multi-detector row computed tomography (MDCT) from one machine. A quality assurance phantom was used to evaluate the stability of the images. The contrast medium lopamidol (lopamiron 300^®; Bayer Health, Osaka, Japan) at 6 different concentrations (0,1, 2.5, 5, 10 and 20%) were placed in 5 mL syringes. Test objects were positioned in several patterns and both CBCT and MDCT images were obtained. The pixel density was measured and analyzed with an image workstation. We found that the CBCT image became less dense closer to the edge of the imaging area, while the density of the MDCT image was stable throughout. A strong correlation was observed between the pixel density of CBCT and the CTN of MDCT in the same materials. Placing materials around the object resulted in smaller values. We concluded that the density near the center of the field of view (FOV) is accurate in CBCT images. A high correlation and linear relationship between the CTN and pixel density were observed for each parameter.

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Autologous blood injection (ABI) in the temporomandibular joint (TMJ) as a treatment for habitual TMJ dislocation is a simple technique that can be performed on an outpatient basis. We investigated the MRI findings one hour after ABI around the TMJ capsule for habitual TMJ dislocation. The subjects were 6 patients seen at the First Department of Oral and Maxillofacial Surgery, Osaka Dental University, who had been diagnosed with habitual TMJ dislocation. All were female, between the ages of 17 and 87 years, with an average age of 66 years. After all of the patients underwent one hour of ABI to their TMJ as treatment for habitual TMJ dislocation, we investigated the MRI findings. There were two significant findings. The first was similar to hematoma and/or joint effusion in the TMJ capsule (6/6 ; 100%). The second was a sporadic and diffuse T2 signal found around the TMJ capsule (3/6 ; 50%).

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We examined changes in the pharyngeal airway space of prognathic patients undergoing sagittal split ramus osteotomy (SSRO) surgery. The subjects were selected from skeletal Class III patients who had received orthognathic surgery. To compare jaw relationships, the position of the hyoid bone and pharyngeal airway space were examined for each case using sets of two lateral cephalometric radiographs that were taken before surgery (T0) and one or more years after surgery (T1).
We found that the jaw relationships improved significantly in all cases after the surgery because the ANB angle increased 4.9 degrees from T0 to T1. In addition, there was no significant post-operative difference on the palatal pharyngeal airway space. On the contrary, the superior, middle and epiglottic pharyngeal airway space decreased significantly. These results suggest that the pharyngeal airway space decreased after SSRO surgery of skeletal Class III patients, although narrowing of this space did not cause breathing disorders

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Dexmedetomidine hydrochloride (Dex) was administered to rabbits to investigate its effect on mean arterial pressure (MAP), regional cerebral blood flow (r-CBF), and intracranial pressure (ICP). Cerebral autoregulation after the discontinuation of Dex infusion at 30 min was also examined. After hemodynamic parameters were stabilized, each animal received infusions of saline at 1 mL/kg/hr, Dex at 10 μg/kg/hr (Dex 10), and Dex at 30 μg/kg/hr (Dex 30) for 30 minutes each in sequence. The animals were exsanguinated immediately after the Dex 30 infusion to observe changes in MAP and r-CBF. MAP decreased significantly from baseline 15 min after infusion of Dex 10, and 10 min after infusion of Dex 30. r-CBF decreased from baseline significantly at 30 min with Dex 10 and after 10 min with Dex 30. No substantial changes in ICP were observed during Dex infusion. During the decrease in MAP caused by exsanguination, r-CBF decreased only slightly up to the point where MAP decreased to around 45 mmHg. These findings indicate that autoregulation is maintained during treatment with Dex 10 and Dex 30 even when blood pressure decreases, and ICP is not affected by Dex at the doses investigated.

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Periodontitis is a chronic inflammatory disease characterized by alveolar bone resorption. Inflammation-mediated bone loss is a major cause of various bone diseases, such as chronic periodontitis, and is due to an imbalance in bone remodeling that favors resorption. This imbalance is caused by increased inflammatory cytokines. Interleukin-17A (IL-17A) is a proinflammatory cytokine that is mainly secreted by activated T cells. IL-17A stimulates osteoclastic bone resorption via osteoblasts by inducing the expression of the receptor activator of NF-kB ligand (RANKL). However, little is known about the direct effects of IL-17A on the osteoclast precursors.
We confirmed that IL-17A suppresses the osteoclast differentiation of RAW264.7 cells in the presence of RANKL in a dose-dependent manner. We also found that treatment with SP 600125, a specific inhibitor of c-Jun N-terminal kinase (JNK), significantly inhibits the TRAP activity of RAW264.7 cells, which were stimulated by RANKL. In addition, we found that IL-17 A reduces the phosphorylation of JNK and expressions of c-Fos, which were increased by RANKL stimulation. These results suggest that IL-17A-induces inhibition of JNK phosphorylation and that expression of c-Fos may be one of the factors that suppresses the differentiation of osteoclast precursors into osteoclasts.

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We evaluated pixel density in the images of cone beam computed tomography (CBCT). The results are based on the CT number correlating to the images taken by multidetector computed tomography (MDCT). In this study, we examined the experimental images taken with three CBCT machines and a MDCT device. The data was analyzed for test tubes set in an agar phantom simulating the conditions of the oral cavity. We were able to find a linear correlation between the CT number/pixel density and concentration of the objects. Simulating the conditions of the human oral cavity, the CBCT pixel density of the test tube tended to decrease slightly. Furthermore, when we attached a model of the cervical vertebrae, the pixel density of CBCT decreased. The data graphs of each CBCT had an obvious linear correlation for CT numbers of MDCT between 500 and 1,300. Therefore, we concluded that the pixel density obtained from CBCT was almost as stable as the CT number under conditions similar to clinical practice in dentistry. By employing established formulas based on the correlation, we found that the pixel density of the CBCT could be converted to CT number using a range of predetermined restrictions.

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We evaluated the ability of titanium nanosheet-modified surfaces of titanium plates to affect cellular gene expression related to osteogenic differentiation. To create the nanostructures, titanium discs were incubated in 10 M NaOH solution at 30℃ for 24 h, and then washed and dried. Cell culture experiments were performed with Sprague-Dawley rat bone marrow cells, which were seeded into microplate wells and cultured in medium designed to induce osteogenic differentiation. We measured alkaline phosphatase (ALP), osterix (OSX), bone morphogenetic protein (BMP), and osteopontin (OPN) gene expression to assess the levels of bone differentiation. After 3 days, cellular ALP and OSX expression was significantly higher in the test group than in the controls. After 7 days, the cells in the test group showed significantly higher BMP and OPN gene expression than those in the controls. These data suggest that titanium implants modified by application of nanostructures promote osteogenic differentiation, and may improve the biointegration of these implants into alveolar bone.

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We attempted to establish a dynamic diagnostic system of transplanted cells using a biochemiluminescence reaction that is catalyzed by luciferase. The cells used for transplantation were distributed from an established cell line that was collected originally from Wistar rats whose genome had systemic expression of the luciferase gene. The cultured cells retained their capacity for chemiluminescence, allowing us to use them in experimental transplantation. Neither replicative senescence nor stress-induced senescence was observed during passage of the cells. As the cells that were transplanted into the rat brains with an immunosuppressive agent showed sufficient viability, it was possible for us to identify the pathophysiology of the transplanted cells semiquantitatively by measuring the amount of chemiluminescence in vivo. The results of this study suggest that the luciferase-induced biochemiluminescence would be applicable to the establishment of new diagnostic and treatment techniques, and contribute to the development of a new field of imaging diagnostics.

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We analyzed the relation between the number of missing teeth (MT) and the rate of market share of fluoride containing dentifrice (RMSF) by birth year cohort. The data analysis used the results of 10 Japanese National Surveys of Oral Health from 1952 to 2011. The data of MT for those born from 1926 to 1973 were divided into 8 groups every six years. The changes in MT and RMSF over time were analyzed for each group of birth year cohorts. In the older subjects, MT increased with age, and RMSF was low. In subsequent generations of subjects, MT was low and RMSF high. We found that the decrease in MT correlated with the increase in RMSF, suggesting that the 8020 goal (Japanese 80 years old should have 20 teeth) will be accomplished after 15 years.

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Dental treatment fees in Japan are regulated by the universal public health care system. However, differing family expenditures for dental care have been reported between high and low income groups. This study analyzed recent government data from a national survey to investigate the impact of family income level on household dental expenditures. We found that people with higher income tend to spend a greater percentage of their income for medical and dental care. The purpose of this study was to investigate how this gap can be reduced.

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