Objective:To study the maximum volume of oral cavity (MVOC) of the young adults with normal occlusion and to explore the correlation of MOVC with the height,weight,mouth opening degree and masticatory efficiency.Methods:100 volunteers with normal occlusion(50 for each sex) were enrolled.MVOC was measured by the maximum water capacity method,the height,weight,degree of mouth opening and masticatory efficiency value of the subjects were measured.Results:The average values of MVOC of the male and female were (117.63±15.31) ml and (92.08±14.06) ml respectively(P<0.01).MVOC was positively correlation with the height(r=0.67,P<0.01),weight(r=0.63,P<0.01),degree of mouth opening(r=0.47,P<0.01) and masticatory efficiency(r=0.45,P<0.01).Conclusion:MVOC is moderate-positively correlated and low-positively correlated with mouth opening degree and masticatory efficiency.

BACKGROUND:IPS e.max Presshas an excelent biocompati bility and corrosion resistance, which obtains satisfactory clinical outcomes on dental veneers, inlay and onlay restorations. But little is reported on molar monolithic restoration by IPS e.max Presscrown.
OBJECTIVE:To evaluate the clinical effects of IPS e.max Press crown on molar repair after root canal therapy.
METHODS:Totaly 215 patients with 324 affected molars, including 88 males and 127 females, aged 22-58 years old, were enroled for repairing with IPS e.max Presscrown. Then the color, shape, fracture and edge coloring of the restoration, marginal discrepancy, secondary caries and gingival health status were assessed after a 3-year folow-up.
RESULTS AND CONCLUSION:During the folow-up, 324 dental restorations met the class A standards for color, marginal discrepancy, shape as wel as secondary caries. In addition,3restoration swere fractured, 14 restorations had margin coloring, and 8 restorations appeared to have gingival inflammation. More than 95% restorations were scored grade A. These results indicate that IPS e.max Press crown applied to molar repair after root canal therapy can achieve ideal outcomes.

BACKGROUNDIn March 2013, human cases of infection with a novel A (H7N9) influenza virus emerged in China. The epidemic spread quickly and as of 6 May 2013, there were 129 confirmed cases. The purpose of this study was to analyze the epidemiology of the confirmed cases, determine the impacts of bird migration and temperature changes on the H7N9 epidemic, predict the future trends of the epidemic, explore the response patterns of the government and propose preventive suggestions.

METHODSThe geographic, temporal and population distribution of all cases reported up to 6 May 2013 were described from available records. Risk assessment standard was established by analysing the temperature and relative humidity records during the period of extensive outbreak in three epidemic regions in eastern China, including Shanghai, Zhejiang and Jiangsu provinces. Risk assessment maps were created by combining the bird migration routes in eastern China with the monthly average temperatures from May 1993 to December 2012 nationwide.

RESULTSAmong the confirmed cases, there were more men than women, and 50.4% were elderly adults (age >61 years). The major demographic groups were retirees and farmers. The temperature on the days of disease onset was concentrated in the range of 9°C-19°C; we defined 9°C-19°C as the high-risk temperature range, 0°C-9°C or 19°C-25°C as medium risk and <0°C or >25°C as low risk. The relative humidity on the days of disease onset ranged widely from 25% to 99%, but did not correlate with the incidence of infection. Based on the temperature analysis and the eastern bird migration routes, we predicted that after May, the high-risk region would move to the northeast and inland, while after September, it would move back to north China.

CONCLUSIONSTemperature and bird migration strongly influence the spread of the H7N9 virus. In order to control the H7N9 epidemic effectively, Chinese authorities should strengthen the surveillance of migrating birds, increase poultry and environmental sampling, improve live poultry selling and husbandry patterns and move from a "passive response pattern" to an "active response pattern" in focused preventive measures.

Animals ; Birds ; China ; epidemiology ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza in Birds ; epidemiology ; Temperature

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.
Humans ; Dentistry, Operative ; Consensus ; Endodontics ; Root Canal Therapy ; Dental Care