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Background More than 10 years have passed since the first nationwide study on the reasons for tooth extraction in Japan. In the present study, we conducted the second nationwide survey to update the previous data. Methods This was a descriptive study. A sample population consisting of 5,250 dentists was selected by systematic random sampling using the 2018 membership directory of the Japan Dental Association. The reason for each permanent tooth extraction was documented by each dentist during a period of 1 week from June 4 to June 10, 2018. A questionnaire was provided for documentation. Reasons for tooth extraction were categorised into 6 groups as follows: caries, periodontal disease, fracture, orthodontics, impacted teeth, and others. Results A total of 2345 identified dentists responded to the questionnaire (recovery rate: 44.8%). Information on 7809 extracted teeth from 6398 patients was obtained. Periodontal disease was the main reason for tooth extraction for both sexes (men: 40.4%, women: 34.9%). Caries accounted for 30.2% of tooth extractions among men and 29.0% among women. Periodontal disease was predominant in the groups older than 55 years of age. Dental fracture accounted for 16.8% of tooth extractions among men and 19.2% among women. Conclusions Caries and periodontal disease are still the main reasons for tooth extraction in Japan. Moreover, dentists should note that fractures accounted for approximately one-fifth of permanent tooth extractions after the age of 45 years.

Due to its large bond energy, precisely controllable C–F bond activation is a significant challenge in organic synthesis. A single C(sp3)–F bond transformation of perfluoroalkyl groups is particularly desirable to supply functionalized perfluoroalkyl compounds offering properties that are potentially useful in pharmaceutical and materials chemistry. Recently, the single defluorinative transformation of perfluoroalkyl compounds has been developed via visible-light photocatalysis. Herein, we summarize this field via two main topics. Topic 1 covers the transformations of C(sp3)–F bonds in either perfluoroalkylarenes or perfluoroalkane carbonyl compounds via a defluorinative spin-center shift in the radical anion intermediates. Topic 2 addresses the defluorinative transformations of α-trifluoromethyl alkenes to give gem-difluoroalkenes via a radical/polar crossover process.1 Introduction2 C(sp3)–F Transformations via Defluorinative Spin-Center Shifts3 C(sp3)–F Transformations via a Radical/Polar Crossover Process4 Conclusions

Fixed partial dentures (FPDs) made of 12% Au-Pd alloy are covered under Japan's national health insurance system. The survival rate of such 3-unit fixed FPDs remains unknown, however. The purpose of this retrospective study was to assess their survival rate in the replacement of first molars. A total of 140 FPDs were included, and the endpoint was removal of an FPD. During the observation period, 43 FPDs were removed. The FPD survival rate was 70.2% at 10 yr, 58.2% at 15 yr, and 42.1% at 20 yr according to the Kaplan-Meier method. The estimated mean survival period was 19.4 yr. The main reasons for FPD loss were dental caries (27.9%), separation from the abutment tooth (18.6%), and pulpitis (18.6%). Single factor analysis using the log-rank test showed that two factors influenced FPD survival: a smaller gonial angle and deep pockets around the abutment teeth. This effect was not statistically significant in either case, however (p0.05). The present results suggest that the prevention of caries and of the separation of the dentures from the abutment teeth are important factors in the long-term survival of FPDs.

In this study, we attempted to develop a dental caries prevention method using a bioapatite (BioHap), an eggshell-derived apatite with nanoparticle size and biocompatibility, with a high-concentration fluoride tooth surface application method. The enamel acid resistance after the application of the proposed method was compared with that of a conventional topical application of fluoride using bovine tooth enamel as an example. The tooth samples were divided into three groups based on the preventive treatment applied, and an acid challenge was performed. The samples were evaluated for acid resistance using qualitative and quantitative analytical methods. The BioHap group demonstrated reduced enamel loss and improved micro-Vickers hardness, along with a thick coating layer, decreased reaction area depth, and decreased mineral loss value and lesion depth. The combination of BioHap with high-concentration fluoride led to the formation of a thick coating layer on the enamel surface and better suppression of demineralization than the conventional method, both qualitatively and quantitatively. The proposed biocompatible nano-hydroxyapatite coating method is expected to become a new standard for providing professional care to prevent dental caries.

Background/purpose Tea, coffee and alcohol beverages are called preference beverage and are drunk habitual and in large quantities. Therefore, there is a high possibility that a health risk is caused by the contained components, and risk assessment of intake is essential. However, the risk assessment of fluoride intake from preference beverages has not been sufficiently performed. Materials and methods This study estimated the daily fluoride intake from preference beverages by measuring the fluoride concentration of infusion liquid and measuring the total fluoride content by the microdiffusion method. In addition, Hazard Quotient (HQ) was calculated for children and adults to assess the risk of fluoride intake. Results As a result of this study, tea was the highest in all sample species, the infusion of tea was 1.06–6.68 mg/L and the total fluoride content of tea was 47.05–291.98 mg/kg. Green tea showed the next highest value, 0.26–4.09 mg/L, 21.91–83.68 mg/kg. Herbal tea fluoride levels were 0.07–0.17 mg/L and 0.05–1.90 mg/kg, Unique tea was 0.03–0.60 mg/L and 0.03–32.37 mg/kg, Coffee was 0.03–0.15 mg/L and 0.04–0.64 mg/kg. Conclusion The HQ values calculated from the average daily fluoride intake (DFI) of preference beverages were all within the safe range. Some products made from Camellia sinensis, such as tea and green tea, had 1.66 mg/day as DFI at maximum, and the Child's HQ exceeded 1. These results suggest that habitual consumption of some products requires risk management of dental fluorosis.

This report describes a validation study of data in the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) obtained by nationwide surveys on tooth extractions. The following 3 data sources on tooth extractions in Japan were compared: (1) the Nationwide Survey of the Reasons for Permanent Tooth Extractions in Japan (a previous survey conducted by the present authors); (2) the Statistics on Medical Care Activities in Public Health Insurance; and (3) the 4th NDB Open Data Japan. Source 1 was a nationwide survey conducted in 2018; sources 2 and 3 comprised data that are freely available for use by the public. In Source 1, 2,345 of 5,250 dentists approached responded to the questionnaire (recovery rate: 44.8%). The number of extracted teeth among younger age groups (aged 25-50 years) reported in Source 1 was lower than that in the other two sources. In contrast, the number of extracted teeth among older age groups reported in Source 1 was higher than that reported in the other two sources. However, when stratified by age group, all differences across the 3 sources regarding the mean annual number of tooth extractions were

We have achieved the first anti-borylstannylation of alkynes by using (o-phenylenediaminato)borylstannanes. This reaction afforded 1-boryl-2-stannylalkenes with excellent regio- and stereoselectivity by a radical mechanism. This anti-addition manner is in sharp contrast to the syn-selectivity obtained during transition metal-catalyzed borylstannylation. The mild radical conditions enabled a broad substrate scope, and various types of aromatic and aliphatic alkynes were applicable. The origin of regio- and stereoselectivity was elucidated by DFT calculation of the reaction mechanism. The application of the borylstannylation products to cross- or homocoupling reactions provided ready access to either triarylethenes or bisborylbutadienes.

The purpose of this study was to clinically investigate double-crown-retained removable partial dentures (DRPDs) and abutment teeth at dental clinics. Only cases with complete arch reconstruction were included. Endpoints were replacement of denture and loss of abutment tooth. A total of 213 dentures with 1030 abutment teeth were analyzed. During the observation period, 32 dentures were replaced. The mean observation period was 12.7 (± 6.6) years (range 3 to 36). By the Kaplan-Meier method, survival rate at 10 years was 94.7% and at 20 years was 70.8%. Estimated mean survival period was 27.1 years. Cox regression analysis showed that risk factor for replacement was good occlusion as indicated by Eichner index groups A to B3 (HR 2.81). The main reason for denture replacement was loss of abutment teeth. Survival rate of abutment teeth at 10 years was 83.8% and at 20 years was 66.3%. The analysis revealed six risk factors: male gender (HR 1.76), age range 65–89 years (HR 1.51), posterior teeth (HR 1.60), higher number of present teeth in opposite jaw (HR 1.69), lower number of abutment teeth (HR 1.76), and short inner crown (HR 2.28). DRPDs last over 20 years, making them a durable investment in one’s oral health; their survival is influenced by loss of abutment teeth. In cases where there are few teeth remaining in a jaw, DRPDs represent a suitable treatment that makes use of the remaining teeth, even if the abutment teeth are non-vital.

It has been reported that people who brush their teeth frequently might be more health-conscious and maintain healthier lifestyle habits. The relationship between obesity and oral health behavior in childhood is unknown, however. The aim of the present study was to fill this gap by investigating obesity and factors associated with oral health behavior in Japanese primary and junior high school students. A total of 475 primary school students (fifth-grade, age 10-11 years) and 408 junior high school students (first-grade, age 12-13 years) were included. All the participants underwent a regular health check-up and completed a self-reported questionnaire. The data thus obtained were subjected to multiple logistic regression analyses to identify the relationship between obesity and factors associated with oral health behavior. In primary school students, a dislike of physical activity was the only factor showing a significant association with obesity (p

The purpose of this study was to investigate the relationship among the waist-to-height ratio (WHtR) and the body mass index (BMI) as obesity indicators and gingival inflammation as determined by bleeding on probing (BOP). The participants comprised employees of a milk products company based in Tokyo, Japan. A total of 159 non-diabetic men aged 40 to 59 yr and with a minimum of 28 teeth were included. Multiple logistic regression analysis controlling for age, smoking status, pocket depth, frequency of daily brushing, frequency of weekly interdental brushing, and regular dental attendance was performed to compare the relationships among the obesity indicators and BOP. Participants with good oral hygiene had significantly less BOP than those with poor oral hygiene (p

Purpose: To directly compare the utility for therapeutic outcome prediction of dynamic first-pass contrast-enhanced (CE)-perfusion area-detector computed tomography (ADCT), MR imaging assessed with the same mathematical method and 2-[fluorine-18]-fluoro-2-deoxy-d-glucose–positron emission tomography combined with CT (PET/CT) for non-small cell lung cancer (NSCLC) patients treated with chemoradiotherapy. Materials and Methods: Forty-three consecutive stage IIIB NSCLC patients, consisting of 25 males (mean age ± standard deviation: 66.6 ± 8.7 years) and 18 females (66.4 ± 8.2 years) underwent PET/CT, dynamic CE-perfusion ADCT and MR imaging, chemoradiotherapy, and follow-up examination. In each patient, total, pulmonary arterial, and systemic arterial perfusions were calculated from both perfusion data and SUVmax on PET/CT, assessed for each targeted lesion, and averaged to determine final values. Receiver operating characteristics analyses were performed to compare the utility for distinguishing responders from non-responders using Response Evaluation Criteria in Solid Tumor (RECIST) 1.1 criteria. Overall survival (OS) assessed with each index were compared between two groups by means of the Kaplan–Meier method followed by the log-rank test. Results: Area under the curve (Az) for total perfusion on ADCT was significantly larger than that of pulmonary arterial perfusion (P < 0.05). Az of total perfusion on MR imaging was significantly larger than that of pulmonary arterial perfusion (P < 0.05). Mean OS of responder and non-responder groups were significantly different for total and systemic arterial (P < 0.05) perfusion. Conclusion: Dynamic first-pass CE-perfusion ADCT and MR imaging as well as PET/CT are useful for early prediction of treatment response by NSCLC patients treated with chemoradiotherapy.

This study clarified the existence of seasonal variations of Fluoride concentrations in multiple wells with different depths, and determined the appropriate time to assess chronic Fluoride toxicity considering these variations. There was up to 3.6 times more seasonal variation in F concentration at the same point. The mean F ion concentration was the lowest at 0.0766 ± 0.0197 mg/L in March, and highest at 0.2412 ± 0.0345 mg/L in December. The hazard quotients (HQ) were all < 1 at all points, and the risk of chronic Fluoride toxicity in children was low. It is necessary to carry out multiple measurements, including in periods with low rainfall, due to seasonal variations.

Guidelines for using toothpaste during tooth-brushing in public places during the coronavirus epidemic are lacking. In addition, the advantages and disadvantages of using toothpaste in terms of droplet generation during brushing, the number of droplets generated, and their scatter range are unknown; therefore, we investigated the relationships between diluted toothpaste viscosity, the number of droplets generated, and the droplets’ flight distance. We developed a system to quantitate droplet generation during tooth-brushing. Brushing with water generated 5965 ± 266 droplets; 10.0× diluted toothpaste generated 538 ± 56, 4.00× diluted toothpaste generated 349 ± 15, and 2.00× diluted toothpaste generated 69 ± 27 droplets. Undiluted toothpaste generated no droplets. Droplet number tended to increase with increased toothpaste dilution ratio and decreased viscosity (r = −0.993). The maximum flight distances were 429 ± 11, 445 ± 65, 316 ± 38, and 231 ± 21 mm for water, 10.0×, 4.00×, and 2.00× diluted toothpaste, respectively. The maximum flight distance and toothpaste viscosity correlated negatively (r = −0.999). Thus, the less diluted the toothpaste, the fewer the droplets generated during brushing, and the shorter their flight distance. The use of an appropriate amount of toothpaste is recommended to prevent droplet infection during tooth-brushing.

The purpose of this study was to investigate the survival of removable partial dentures with a mandibular bilateral free end saddle (BFES) and abutment teeth in a clinical setting. Only mandibular dentures with a BFES were included (10 or fewer present teeth, and fewer than 4 occlusal units). The endpoints were replacement of denture and loss of abutment teeth. A total of 128 dentures and 595 abutment teeth were analyzed. Nineteen dentures had to be replaced during the observation period (mean duration: 11.4±6.9 years; range: 3 to 36 years). According to Kaplan-Meier analysis, the survival rate was 93.2% at 10 years and 68.6% at 20 years. The estimated mean survival period was 27.8 years. Single-factor analysis using the log-rank test showed that no factor investigated had a significant influence. The main reason for denture replacement was loss of abutment teeth (47.4%). The survival rate of the abutment teeth was 91.3% at 10 years and 77.3% at 20 years. The analysis revealed 4 significant risk factors: male sex (hazard ratio [HR]: 1.78); premolars (HR: 1.67); a lower number of abutment teeth (HR: 3.24); and history of endodontic treatment (HR: 2.79). The removable partial dentures with a mandibular BFES in this study lasted over 20 years, and their survival was influenced by loss of abutment teeth. Dentures are used continuously over long periods of time and should therefore be designed to allow easy adjustment when abutment teeth are lost.

Background The need for quantitative assessment of interstitial lung involvement on thin-section computed tomography (CT) has arisen in interstitial lung diseases including connective tissue disease (CTD). Purpose To evaluate the capability of machine learning (ML)-based CT texture analysis for disease severity and treatment response assessments in comparison with qualitatively assessed thin-section CT for patients with CTD. Material and Methods A total of 149 patients with CTD-related ILD (CTD-ILD) underwent initial and follow-up CT scans (total 364 paired serial CT examinations), pulmonary function tests, and serum KL-6 level tests. Based on all follow-up examination results, all paired serial CT examinations were assessed as “Stable” (n = 188), “Worse” (n = 98) and “Improved” (n = 78). Next, quantitative index changes were determined by software, and qualitative disease severity scores were assessed by consensus of two radiologists. To evaluate differences in each quantitative index as well as in disease severity score between paired serial CT examinations, Tukey's honestly significant difference (HSD) test was performed among the three statuses. Stepwise regression analyses were performed to determine changes in each pulmonary functional parameter and all quantitative indexes between paired serial CT scans. Results Δ% normal lung, Δ% consolidation, Δ% ground glass opacity, Δ% reticulation, and Δdisease severity score showed significant differences among the three statuses ( P 2 ≤0.42; P Conclusion ML-based CT texture analysis has better potential than qualitatively assessed thin-section CT for disease severity assessment and treatment response evaluation for CTD-ILD.

Sodium monofluorophosphate (MFP) is a component of fluoride-containing dentifrices and is more biosafe than the conventional sodium fluoride (NaF). MFP can respond not only on the tooth surface layer but also deep into the enamel. We aim to confirm that high concentrations of acid phosphate MFP (AP-MFP, 9000 ppmF), used in professional care, could lead to a highly biosafe fluoride application method that acts through the deep enamel layers. Sample groups were respectively treated in vitro with NaF, acidulated phosphate fluoride (APF), MFP, and AP-MFP, and the samples were compared against an untreated group. Characterizations after fluoride application confirmed that MFP and AP-MFP treatments improved the acid resistance of enamel compared to that of conventional methods. Furthermore, the acid resistance of highly concentrated MFPs improved by using phosphoric acid. Although the acid resistance from the AP-MFP method is not as good as that using APF, AP-MFP can act both on the surface layer and deep into the enamel. Moreover, AP-MFP retains fluoride ions as much as APF does on the tooth surface. The proposed fluoride application method using AP-MFP introduces a dental treatment for acid resistance that is highly biosafe and penetrates deep layers of the enamel.

Purpose To prospectively compare the capability of dynamic first-pass contrast-enhanced (CE) perfusion MR imaging with ultra-short TE and area-detector CT (ADCT), analyzed with the same mathematical methods, and that of FDG-PET/CT for diagnosis and management of solitary pulmonary nodules (SPNs). Methods and materials Our institutional review board approved this study and written informed consent was obtained from all subjects. A total 57 consecutive patients with 71 nodules prospectively underwent dynamic CE-perfusion ADCT and MR imaging with ultra-short TE, FDG-PET/CT, as well as microbacterial and/or pathological examinations. The nodules were classified into malignant nodules (n = 45) and benign nodules (n = 26). Pulmonary arterial, systemic arterial and total perfusions were determined by means of dual-input maximum slope models on ADCT and MR imaging and maximum values of standard uptake values (SUVmax) on PET/CT. Receiver operating characteristic (ROC) analysis was performed for each index, and sensitivity, specificity and accuracy were compared by McNemar's test. Results Areas under the curve (Azs) of total perfusion on ADCT (Az = 0.89) and MR imaging (Az = 0.88) were significantly larger than those of systemic arterial perfusion and MR imaging (p Conclusion Dynamic CE-perfusion MR imaging with ultra-short TE and ADCT and have similar potential capabilities, and are superior to FDG-PET/CT in this setting.

Active oxygen and free radicals are involved in metabolism in cells and tissues. Immunohistological studies of related enzymes are few, and the morphological dynamics of these enzymes in dental pulp and odontoblasts remain to be elucidated. Nitric oxide synthase (NOS) has 3 isoforms: nNOS, iNOS, and eNOS. The aim of this study was to investigate the profiles of NOS isoforms in the absence of nNOS in dental pulp and odontoblasts. Five-week-old male C57BL/6 and nNOS knockout (KO) mice were sacrificed and expression of nNOS, iNOS, and eNOS determined immunohistochemically. Expression of nNOS was positive, whereas that of iNOS was negative and eNOS weakly positive in the dental pulp and odontoblasts of the control mice. In nNOS KO mice, expression of iNOS was positive in dental pulp and strongly positive in odontoblasts, whereas that of eNOS was stronger in fibroblasts, endothelial cells in the vicinity of blood vessels in the dental pulp, and odontoblasts. Expression of nNOS was negative in the nNOS KO mice. This suggests that iNOS and eNOS compensate for nNOS deficiency in vascular endothelial cells and fibroblasts in the dental pulp and odontoblasts.

Site-selective and direct C-F bond transformation of perfluoroalkylarenes was achieved with allylic stannanes via an iridium photoredox catalyst system. The present defluoroallylation proceeds exclusively at the benzylic position through perfluoroalkyl radicals generated by a single-electron transfer from an excited photoredox catalyst to perfluoroalkylarenes. A variety of perfluoroalkyl groups are applicable: linear perfluoroalkyl-substituted arenes such as Ar-nC4F9 and Ar-nC6F13 and heptafluoroisopropylarenes (Ar-CF(CF3)2) underwent site-selective defluoroallylation. DFT calculation studies revealed that the in situ generated Bu3SnF traps F- to prevent a retroreaction from the unstable perfluoroalkyl radical intermediate, and the radical intermediate favorably reacts with allylic stannanes. The synthesis of a bis(trifluoromethyl)methylene unit containing compound, which is an analog that is useful as a pharmaceutical agent for the prophylaxis or treatment of diabetes and inflammatory diseases, demonstrated the utility of this reaction.

The relationship between public health expenditure and number of teeth was investigated in patients with diabetes mellitus using data obtained from the Japanese National Database of Health Insurance Claims and Specific Health Checkups. Data on medical, dental, and pharmacy claims generated between April 2015 and March 2016 were analyzed in patients with diabetes mellitus aged 50-74 years who used outpatient services during this period. Patients initiating medical and pharmacy claims related to diabetes mellitus were defined as having diabetes mellitus. Number of teeth was defined as number of teeth in conjunction with periodontitis due to the nature of the data source. Descriptive statistics were used to investigate the association between number of teeth and public health expenditure. Data on a total of 1,017,758 patients with diabetes mellitus were analyzed. Patients with the fewest teeth incurred higher medical expenses. The largest mean difference in medical expenditure was observed between patients with 5-9 teeth and those with over 28 teeth. The results of this study suggest that public health expenditure on patients with diabetes mellitus differs based on number of teeth.

Purpose To evaluate the capability of inspiratory/expiratory Xe-enhanced ADCT for assessment of changes in pulmonary function and regional ventilation of surgically treated NSCLC patients. Method and materials Forty consecutive surgically treated NSCLC patients underwent pre- and postoperative inspiratory/expiratory Xe-enhanced ADCT and pulmonary function tests. For each patient, pre- and post-operative data were analyzed and pre- and post-operative wash-in (WI) and wash-out (WO) indexes and ventilation ratio (VR=[WI-WO]/WI) maps generated by means of pixel-by-pixel analyses. Differences between pre- and postoperative WI (ΔWI), WO (ΔWO) and VR (ΔVR) were also determined. To determine the relationship between all ventilation index changes and pulmonary functional loss, Pearson’s correlation was used to correlate each ventilation index change with the corresponding pulmonary functional parameter change. In addition, stepwise regression analysis was performed for all ventilation index changes and each corresponding pulmonary functional parameter change. Results FEV1/FVC% change showed fair or good and significant correlations with ΔWI (r = 0.39, p = 0.01) and ΔVR (r = 0.68, p = 0.001), %FEV1 change good or moderate and significant correlations with ΔWI (r = 0.56, p = 0.0001) and ΔVR (r = 0.76, p Conclusion Inspiratory/expiratory Xe-enhanced ADCT has the potential to demonstrate that pre- and postoperative ventilation status of surgically treated NSCLC patients correlates with pulmonary function.

Effect of silicon (Si) addition on the chemical corrosion resistance of hydrogenated amorphous carbon (a-C:H) was investigated. Hydrogenated amorphous carbon and Si-incorporated a-C:H (a-C:H:Si) films were deposited by plasma-enhanced chemical vapor deposition using C2H2 and tetramethylsilane as source materials. Etching rates of these films in HNO3 and NaOH solutions were evaluated using surface plasmon resonance. Evaluation of etching rate in the NaOH solution showed that no etching occurred on the a-C:H film, although the a-C:H:Si film was etched by NaOH solution. From these results, corrosion of a-C:H and a-C:H:Si films in nitric acid progresses by the oxidization of sp2-hybridized bonded carbon. Also, Si-incorporation to a-C:H films improved the corrosion resistance by decreasing the ratio of sp2-hybridized bonded carbon. Si-incorporation to a-C:H films improved their robustness against corrosion in HNO3 solution by the formation of SiOx structures, while it reduced the corrosion resistance against NaOH solution.

To directly compare the effect of a reconstruction algorithm on nodule detection capability of the computer-aided detection (CADe) system using standard-dose, reduced-dose and ultra-low dose chest CTs with and without adaptive iterative dose reduction 3D (AIDR 3D).Our institutional review board approved this study, and written informed consent was obtained from each patient. Standard-, reduced- and ultra-low-dose chest CTs (250 mA, 50 mA and 10 mA) were used to examine 40 patients, 21 males (mean age ± standard deviation: 63.1 ± 11.0 years) and 19 females (mean age, 65.1 ± 12.7 years), and reconstructed as 1 mm-thick sections. Detection of nodule equal to more than 4 mm in dimeter was automatically performed by our proprietary CADe software. The utility of iterative reconstruction method for improving nodule detection capability, sensitivity and false positive rate (/case) of the CADe system using all protocols were compared by means of McNemar's test or signed rank test.Sensitivity (SE: 0.43) and false-positive rate (FPR: 7.88) of ultra-low-dose CT without AIDR 3D was significantly inferior to those of standard-dose CTs (with AIDR 3D: SE, 0.78, p .0001, FPR, 3.05, p .0001; and without AIDR 3D: SE, 0.80, p .0001, FPR: 2.63, p .0001), reduced-dose CTs (with AIDR 3D: SE, 0.81, p .0001, FPR, 3.05, p .0001; and without AIDR 3D: SE, 0.62, p .0001, FPR: 2.95, p .0001) and ultra-low-dose CT with AIDR 3D (SE, 0.79, p .0001, FPR, 4.88, p = .0001).The AIDR 3D has a significant positive effect on nodule detection capability of the CADe system even when radiation dose is reduced.

The objective of this study was to compare the capability of xenon-enhanced area-detector CT (ADCT) performed with a subtraction technique and coregisteredForty-six consecutive smokers (32 men and 14 women; mean age, 67.0 years) underwent prospective unenhanced and xenon-enhanced ADCT,Multivariate logistic regression showed that %FEVXenon-enhanced ADCT is more effective than

The purpose of this study was to determine the distribution of healthy elderly individuals undergoing regular dental check-ups and identify any environmental or associated oral factors. A cross-sectional questionnaire survey was used to interview 216 individuals attending 2 welfare facilities for the elderly, of whom 160 were included in the final analysis. Items comprised age, sex, number of residual teeth, frequency of teeth/denture cleaning, subjective chewing ability, denture use, oral status, regular dental check-ups, visitation of the same dentist, number of dental visits in the past year, General Oral Health Assessment Index (GOHAI) (Japanese version) score, living situation, and use of routine medication. Individuals undergoing regular dental check-ups were defined as those with a primary dentist whom they saw for dental check-ups at least once a year. The rate of individuals undergoing regular dental check-ups was 75.0% in men aged 60-74 years, 58.8% in women aged 60-74 years, 70.0% in men aged 75 years or over, and 45.3% in women aged 75 years or over. Logistic regression analysis revealed a higher number of residual teeth (odds ratio [OR]=2.664 in comparison with those with fewer than 20 teeth, p=0.0427); cleaning teeth/dentures 3 or more times per day (OR=2.546 in comparison with cleaning them twice per day or less, p=0.0157); and a higher GOHAI score (OR=2.742 in comparison with those with a GOHAI score of less than 58, p=0.0263) as factors significantly correlated with undergoing regular dental check-ups. In conclusion, the results revealed that individuals undergoing regular dental check-ups had 20 or more residual teeth, cleaned their teeth/denture 3 or more times per day, and had a higher GOHAI score. This indicates that the best predictive factor for undergoing regular dental check-ups in healthy elderly individuals is their GOHAI score.

Diabetes mellitus is closely related to oral health. We aimed to determine the relationship between diabetes mellitus and tooth extraction due to periodontal disease and dental caries. Japan’s second nationwide survey data collected from 4 June to 10 June 2018 was used to identify reasons for tooth extraction among patients aged &gt, 40 years. General dentists collected information on patients who underwent tooth extraction procedures, and the presence of diabetes mellitus was determined through interviews. Multivariable logistic regression was performed to investigate the relationship between diabetes mellitus and the reasons for tooth extraction, including periodontal disease and dental caries. In total, 2345 dentists responded to the survey (response rate 44.8%). We analyzed data on 4625 extracted teeth from 3750 patients (1815 males and 1935 females). Among patients with self-reported diabetes mellitus, 55.4% had extractions due to periodontal disease compared to 46.7% of such extractions among those without self-reported diabetes mellitus. Self-reported diabetes mellitus was significantly associated with tooth extraction due to periodontal disease. No significant differences were observed in dental caries according to self-reported diabetes mellitus status. This study provides further evidence of a significant association between diabetes mellitus and tooth extraction due to periodontal disease.

The objective of our study was to directly compare the capability of dynamic first-pass contrast-enhanced (CE) perfusion area-detector CT (ADCT) and FDG PET/CT for differentiation of metastatic from nonmetastatic lymph nodes and assessment of N stage in patients with non-small cell lung carcinoma (NSCLC).Seventy-seven consecutive patients, 45 men (mean age ± SD, 70.4 ± 5.9 years) and 32 women (71.2 ± 7.7 years), underwent dynamic first-pass CE-perfusion ADCT at two or three different positions for covering the entire thorax, FDG PET/CT, surgical treatment, and pathologic examination. From all ADCT data for each of the subjects, a whole-chest perfusion map was computationally generated using the dual- and single-input maximum slope and Patlak plot methods. For quantitative N stage assessment, perfusion parameters and the maximum standardized uptake value (SUVThe area under the ROC curve (ADynamic first-pass CE-perfusion ADCT is as useful as FDG PET/CT for the differentiation of metastatic from nonmetastatic lymph nodes and assessment of N stage in patients with NSCLC.

We propose using a slide-ring (SR) gel electrolyte to achieve a gel polymer electrolyte with both sufficient mechanical strength and high ionic conductivity. The SR gel is made from polyrotaxane, which has a structure that consists of cyclic molecules, α-cyclodextrins (CDs), threaded by an axial polymer chain, polyethylene glycol (PEG), and cross-linked by divinyl sulfone. The SR gel electrolyte was made from SR gels which were swollen by an electrolyte solution (ES) prepared with lithium salt and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI). The swelling behavior of SR gel in the ES by the formation of coordination bonds between lithium cations and oxygen atoms on CDs was investigated. The swelling behavior and ionic conductivity of the SR gel swollen with ES had a peak at 0.8 M lithium ion in the ES and the molar conductivity of the SR gel swollen with ES was 85% more than that of pristine ES. The puncture resistance of the SR gel electrolyte was also investigated; the puncture elongation was more than 1000% and the Young’s modulus increased with the lithium ion concentration due to an increase in the coordination bonds between lithium cations and the oxygen atoms on CDs.

Objective: Continuous or frequent overtime work has been shown to have harmful effects on human health. Meanwhile, one of the main reasons for tooth loss is caries. The aim of this study was to assess the relationship between overtime work and untreated decayed teeth in male financial workers. Methods: The participants were recruited by applying screening procedures to a pool of Japanese registrants in an online database. Participants filled out a questionnaire about their oral health, behavior, and working conditions. Participants comprised a total of 951 financial male workers, aged 25-64 years. Results: The likelihood of tooth decay increased with amount of overtime work (p=0.002). After adjusting for age, income, educational background, oral hygiene behavior, snacking behavior, regular dental visitation, bad interpersonal relationships at work, and smoking habit, a multiple logistic regression analysis found that participants with 45-80 h of overtime work (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.23-5.33) or over 80 h of overtime work (OR, 3.01; 95% CI, 1.13-7.97) were more likely to have untreated tooth decay. The percentage of participants who gave "too busy with work" as the reason for leaving decayed teeth untreated increased with amount of overtime (p

The aim of this study was to identify factors in the working environment associated with regular dental attendance. Thirty-three general practitioners provided data on 488 patients who underwent dental maintenance between 2003 and 2015. The age of the patients ranged from 40 to 65 years. Appointment adherence, employment format, overtime work, night work, and subjective evaluation of work were investigated. Multiple logistic regression analysis was performed to identify factors associated with regular dental attendance. Among all participants, 296 (60.7%) were female, 320 (65.6%) worked full-time, 193 (39.5%) worked overtime, and 34 (7.0%) worked nights. The results of the analysis revealed that only night work was a significant factor after adjusting for sex, age, and employment format (odds ratio, 0.220; 95% confidence interval, 0.088-0.550). The results of this study suggest that night work disturbs regular dental attendance.

To prospectively and directly compare the capability for assessments of regional ventilation and pulmonary functional loss in smokers of xenon-ventilation CT obtained with the dual-energy CT (DE-CT) and subtraction CT (Sub-CT) MATERIALS AND METHODS: Twenty-three consecutive smokers (15 men and 8 women, mean age: 69.7±8.7years) underwent prospective unenhanced and xenon-enhanced CTs, the latter by Sub-CT and DE-CT methods, ventilation SPECT and pulmonary function tests. Sub-CT was generated from unenhanced and xenon-enhanced CT, and all co-registered SPECT/CT data were produced from SPECT and unenhanced CT data. For each method, regional ventilation was assessed by using a 11-point scoring system on a per-lobe basis. To determine the functional lung volume by each method, it was also calculated for individual sublets with a previously reported method. To determine inter-observer agreement for each method, ventilation defect assessment was evaluated by using the χ2 test with weighted kappa statistics. For evaluation of the efficacy of each method for pulmonary functional loss assessment, functional lung volume was correlated with%FEVEach inter-observer agreement was rated as substantial (Sub-CT: κ=0.69, p0.0001; DE-CT: κ=0.64, p0.0001; SPECT/CT: κ=0.64, p0.0001). Functional lung volume for each method showed significant to good correlation with%FEVXenon-enhanced CT obtained by Sub-CT can be considered at least as efficacious as that obtained by DE-CT and SPECT/CT for assessment of ventilation abnormality and pulmonary functional loss in smokers.

The purpose of this study was to investigate the effectiveness of the Communication Studies Program at Tokyo Dental College as a tool in behavioral education. The number of Patient Community members who had participated in multiple sets of the program for third-year students in the same year within the 3-year period spanning 2016 to 2018 (152, 148, and 129 students in 2016, 2017, and 2018 respectively), and the period during which they had participated in multiple sets were investigated. Comments on student behavior, including on hairstyle, clothes, and attitude, were also analyzed. The total number of members who had participated in multiple sets (1 set comprised 1 lecture and 2 training sessions) was 5; and their comments were more favorable during the second (sets 3 and 4) than the first half of the 1-month program (sets 1 and 2). During the first half, the students were criticized for speaking softly, having bad posture, not concentrating, and having an attitude inappropriate for a medical worker; but in the second half, they were praised for beginning to adopt the proper attitude for a medical worker, speaking louder, having better posture, and a very serious attitude. These findings suggest that the Communication Studies Program is effective in improving student behavior.

Background Although diabetes mellitus is reported to be related to tooth loss, there is limited population-based evidence for this relationship. We investigated the actual situation of tooth loss by performing a population-based survey using information obtained from the National Database of Health Insurance Claims and Specific Health Checkups (NDB) in Japan. Methods Medical, dental and pharmacy claims data generated between 1 April 2015 and 31 March 2016 were obtained and analysed. Patients with medical and pharmacy claims of diabetes mellitus were allocated to the diabetes mellitus group. Patients with medical claims of acute upper respiratory inflammation, but without claims of diabetes mellitus, were allocated to the control group. The number of claims involving tooth loss, treatment of periodontal disease and visits to medical and dental institutions were obtained from the NDB. Descriptive statistics were used to compare the nature of tooth loss between patients with diabetes mellitus and the control groups. Results There were 5,248,405 patients in the control group and 1,570,082 patients in the diabetes mellitus group. Patients in the diabetes mellitus group showed a higher level of tooth loss than patients in the control group, among both sexes. Patients with diabetes mellitus tended to lose their posterior teeth at an earlier age than patients in the control group. Moreover, patients in the diabetes mellitus group showed greater tooth loss, regardless of whether or not periodontal disease was treated. Conclusion Patients with diabetes mellitus show a higher level of tooth loss than those without diabetes mellitus, based on the results of a population-based survey.

The purpose of this study was to identify factors associated with untreated decayed teeth (DT) in male sales workers. The participants were recruited by screening a pool of Japanese registrants in an online database for eligibility for inclusion in the study. Between 20 February 2015 and 11 March 2015, those deemed eligible were asked to complete a questionnaire on the status of their oral health. Responses from a total of 142 male sales workers aged between 30 and 49 years were analyzed. Of these, 40 reported DT and 102 no untreated decayed teeth (NDT). The percentage of participants with DT was higher than that with NDT among night shift workers (p

BackgroundXenon (Xe)-enhanced area-detector computed tomography (ADCT) can visualize regional distribution of Xe within the lungs and demonstrate regional ventilation differences in smokers and pat...

The purpose of this cross-sectional study was to determine whether there is an association between hemoglobin A1c (HbA1c) level and the presence or absence of decayed teeth in patients with type 2 diabetes mellitus. The patients and data on their age and sex, the presence or absence of dental claims, medical history of diabetes mellitus, and workplace dental examinations were obtained from a Japanese healthcare database available for epidemiological studies. The HbA1c levels were obtained from results of the Specific Health Checkups and Specific Health Guidance tests conducted by the Japanese Ministry of Health, Labour and Welfare. Data on a total of 1,897 patients were analyzed. Patients with poorly controlled diabetes (HbA1c≥6.5, n=779) had more decayed teeth than those in whom it was well controlled (HbA1c

To determine the value of a raw data-based metal artifact reduction (SEMAR) algorithm for image quality improvement in abdominal CT for patients with small metal implants. Fifty-eight patients with small metal implants (3–15 mm in size) who underwent treatment for hepatocellular carcinoma were imaged with CT. CT data were reconstructed by filtered back projection with and without SEMAR algorithm in axial and coronal planes. To evaluate metal artefact reduction, mean CT number (HU and SD) and artefact index (AI) values within the liver were calculated. Two readers independently evaluated image quality of the liver and pancreas and visualization of vasculature using a 5-point visual score. HU and AI values and image quality on images with and without SEMAR were compared using the paired Student’s t-test and Wilcoxon signed rank test. Interobserver agreement was evaluated using linear-weighted κ test. Mean HU and AI on images with SEMAR was significantly lower than those without SEMAR (P