乳歯列期における前歯部交叉咬合の処置法の検討および考察

The purpose of this study was to analyze the factors related to anterior crossbite in deciduous dentition and observe relapse after correction until the eruption of permanent anterior teeth. In this study, 50 Chinese children aged 4-6 years old with anterior crossbite of deciduous dentition were analyzed for the relevant factors and different correction methods. The occurrence of relapse was observed. The relapse rate of the hereditary group was the highest. The relapse rate of the group treated with an inclined lower anterior bite plate was lower than that of those treated with a removable appliance with a posterior bite plate and anterior lingual springs. Improper oral habits are a key problem in the anterior crossbite of deciduous dentition, and children with such oral habits-related anterior crossbite should be treated at their early age

<ORIGINAL REPORT>X-ray scanning analytical microscopic and scanning electron microscopic studies of an unusual case of dens invaginatus

A mass was extirpated from the region of the maxillary right third molar of a 20 year-old patient. It was proved to be an extreme and unerupted case of dens invaginatus. The clinical and histopathological features have been presented in a previous paper. Ameloblasts and odontoblasts were noted along the surface of enamel or dentin. In the present study, X-ray scanning analytical microscopy (XSAM), a newly developed technique, together with scanning electron microscopy (SEM) was applied for the study of this malformed tooth. SEM study showed a strange arrangement of well-formed enamel and dentin in normal structures. The distribution of calcium (Ca) and phosphorus (P) was clearly observed by the XSAM method. It revealed that the bulk of dentin was composed of two kinds of dentin quite different in mineral content while their SEM appearances were similar. The part of the dentin near the dentinoenamel junction had much higher Ca and P concentrations than the outer parts. In conclusion, the disagreement between the microscopic findings and the XSAM findings suggests the importance of applying various methods in studies to obtain a comprehensive understanding of such malformation. In addition, the present investigation also points out the complexity of the disturbance ranging within the term dens invaginatus

中国上海市小児における乳歯列形態の検討 : 正常咬合児72例の模型から

To obtain the dimensional data of the dental casts of growing and developing Chinese children, and to compare the data to the Japanese, we have performed dental examinations on children in the kindergarten attached to Shanghai Teachers\u27 University in Shanghai since 1996. As study materials, dental casts obtained between 1996 and 1999 from 72 Chinese children aged 3 to 6 years with normal primary occlusion were used to evaluate the mesio-distal crown diameters of the primary teeth, the sizes of the primary dental arch, and the standard values and frequency distributions of primary occlusion. 1. Males showed higher values in mesio-distal crown diameters in deciduous teeth, and the size of dental arch than females. 2. In regard to the interdental spaces both in the maxilla and mandible, primate and developmental spaces together were most frequently observed. 3. In regard to the occlusal relationship, the incidence of terminal planes was higher in the order of Vertical type > Mesial step type > Distal step type, and the incidence of primary canine occlusal relationship was higher in the order of type I>type III>type II. 4. The items that were thought to be characteristic of Chinese children were the frequency of only primate spaces, and the incidence of the Mesial step type of terminal plane and type III primary canine occlusal relationship

Local H2 release remodels senescence microenvironment for improved repair of injured bone

Abstract The senescence microenvironment, which causes persistent inflammation and loss of intrinsic regenerative abilities, is a main obstacle to effective tissue repair in elderly individuals. In this work, we find that local H2 supply can remodel the senescence microenvironment by anti-inflammation and anti-senescence effects in various senescent cells from skeletally mature bone. We construct a H2-releasing scaffold which can release high-dosage H2 (911 mL/g, up to 1 week) by electrospraying polyhydroxyalkanoate-encapsulated CaSi2 nanoparticles onto mesoporous bioactive glass. We demonstrate efficient remodeling of the microenvironment and enhanced repair of critical-size bone defects in an aged mouse model. Mechanistically, we reveal that local H2 release alters the microenvironment from pro-inflammation to anti-inflammation by senescent macrophages repolarization and secretome change. We also show that H2 alleviates the progression of aging/injury-superposed senescence, facilitates the recruitment of endogenous cells and the preservation of their regeneration capability, thereby creating a pro-regenerative microenvironment able to support bone defect regeneration

Association between Shift Work and Health Outcomes in the General Population in China: A Cross-Sectional Study

Shift work may adversely affect individuals’ health, thus, the current study aimed to investigate the association between shift work and health outcomes in the general population. A total of 41,061 participants were included in this online cross-sectional survey, among which 9612 (23.4%) individuals engaged in shift work and 31,449 (76.6%) individuals engaged in non-shift work. Multiple logistic regression analyses were conducted to explore the association between shift work and health outcomes (psychiatric disorders, mental health symptoms, and physical disorders). In addition, associations between the duration (≤1 year, 1–3 years, 3–5 years, 5–10 years, ≥10 years) and frequency of shift work (p p p < 0.001). In addition, inverted U-shaped associations were observed between the duration of shift work and health outcomes. These results indicated that shift work was closely related to potential links with poor health outcomes. The findings highlighted the importance of paying attention to the health conditions of shift workers and the necessity of implementing comprehensive protective measures for shift workers to reduce the impact of shift work

Association of Symptoms of Attention Deficit and Hyperactivity with Problematic Internet Use among University Students in Wuhan, China During the COVID-19 Pandemic

BACKGROUND: COVID-19 is still spreading worldwide and posing a threat to individuals’ physical and mental health including problematic internet use (PIU). A potentially high-risk group for PIU are those with symptoms of attention deficit and hyperactivity (ADHD symptoms), because of restrictions in their physical activity levels and engagement in computer diversions requiring only short attention spans. METHODS: We used convenience sampling in a cross-sectional survey of university students from 30 universities in Wuhan, Hubei Province, China. We assessed PIU using the Internet Addiction Test and ADHD symptoms using the WHO Adult ADHD Self-Report Screening Scale. Using logistic regression and linear regression analyses we adjusted for demographic, epidemic-related and psychological covariates in models of the association between ADHD symptoms and PIU. RESULTS: Among 11,254 participants, we found a 28.4% (95% CI, 27.5%-29.2%) prevalence of PIU, relatively higher than before the pandemic. In our final logistic regression model, participants with ADHD symptoms had approximately two times the risk for PIU (OR: 2.31, 95% CI: 1.89-2.83). Similarly, individuals with depression, anxiety, insomnia, PTSD symptoms and feeling stress during the pandemic had a higher risk of PIU, while those exercising regularly during the pandemic had a lower risk. LIMITATIONS: The cross-sectional design and reliance on internet based self-reports for ADHD symptoms and PIU assessments, without direct structured interviews for validation, are limitations. CONCLUSIONS: The prevalence of PIU was high during COVID-19, and those people with ADHD symptoms and other mental illness symptoms appear to be at higher risk of PIU. Regular exercise may reduce that PIU risk and hence should be recommended during the COVID-19 pandemic