Spatial analysis and influencing factors of pulmonary tuberculosis among students in Nanning, during 2012-2018.

BACKGROUND: Economically underdeveloped areas in western China are hotspots of tuberculosis, especially among students. However, the related spatial and temporal patterns and influencing factors are still unclear and there are few studies to analyze the causes of pulmonary tuberculosis in students from the perspective of space. METHODS: We collected data regarding the reported incidence of pulmonary tuberculosis (PTB) among students at township level in Nanning, from 2012 to 2018. The reported incidence of pulmonary tuberculosis among students in Nanning was analyzed using spatial autocorrelation and spatial scan statistical analysis to depict hotspots of PTB incidence and spatial and temporal clustering. Spatial panel data of the reported incidence rates and influencing factors at district and county levels in Nanning were collected from 2015 to 2018. Then, we analyzed the spatial effects of incidence and influencing factors using the spatial Durbin model to explore the mechanism of each influencing factor in areas with high disease prevalence under spatial effects. RESULTS: From 2012 to 2018, 1609 cases of PTB were reported among students in Nanning, with an average annual reported incidence rate of 14.84/100,000. Through the Joinpoint regression model, We observed a steady trend in the percentage of cases reported each year (P>0.05). There was spatial autocorrelation between the annual reported incidence and the seven-years average reported incidence from 2012 to 2018. The high-incidence area was distributed in the junction of six urban areas and spread to the periphery, with the junction at the center. The population of college students, per capita financial expenditure on health, per capita gross domestic product, and the number of health technicians per 1,000 population were all influencing factors in the reported incidence of PTB among students. CONCLUSION: We identified spatial clustering of the reported incidence of PTB among students in Nanning, mainly located in the urban center and its surrounding areas. The clustering gradually decreased from the urban center to the surrounding areas. Spatial effects influenced the reported incidence of PTB. The population density of college students, per capita health financial expenditure, gross domestic product (GDP) per capita, and the number of health technicians per 1,000 were all influencing factors in the reported incidence of PTB among students.

[Color distribution of the anterior teeth in 137 elder people].

PURPOSE: To study the color distribution of the anterior teeth in elder people. METHODS: 612 anterior teeth from 137 people aging from 60 to 81 years and 200 anterior teeth from 100 young people aging from 20 to 40 years were collected. A digital colorimeter was used to measure the value of L*,a*,b* of the teeth, and the chromatism (deltaE) was calculated according to the formula deltaE=(deltaL*(2)+deltaa*(2)+deltab*(2))1/2. All data were analyzed with SAS 6.12 software package for Student's t test. RESULTS: Totally, there were 612 vital anterior teeth from elder people, including 201 central incisors,199 lateral incisors and 212 canines, were collected. No difference was found between the teeth on the right side and the left side in terms of L*,a*,b*value(P>0.05). The mean value of L*,a*,b* of the central incisors was 71.2+/-6.22,0.97+/-1.12,15.9+/-5.04, respectively and that of the lateral incisors and the canines were 69.6+/-5.52,0.6+/-1.18,13.9+/-4.15 and 68.4+/-5.99,0.15+/-1.02,19.6+/-4.87, respectively.The mean value of L*,a*,b* of the central incisors and the canines from the youngster was 75.82,-0.11,12.68 and 72.07,1.22,17.92, respectively.There were significant differences between the central incisors and the lateral incisors as well as the canines (P<0.05) in terms of L* value. Meanwhile difference was also found among the incisors and the canines in terms of a* and b* value(P<0.05). The deltaE between the central incisors and the lateral incisors was 2.945NBS, and the value between the canines and the central incisors as well as the lateral incisors was 4.629NBS and 5.832NBS, respectively, indicating that the color difference could be perceived visually. Compared to the youngster, the teeth of the elder people demonstrated a lower L* and a* value, but a higher b* value (P<0.05). CONCLUSIONS: Among elder people, the central incisors look much brighter than the lateral incisors and canines, while the canines have more redness and yellowness than the incisors, and the color of the lateral incisors exhibits lighter than the central incisors and the canines. Compared to the teeth from younger people, the teeth from elder people look much darker and yellower but less red. Supported by Shanghai Leading Academic Discipline Project (Grant No.T0202).

[The influence of the try-in pastes on the colour of all-ceramic veneers].

PURPOSE: To study the influence of the try-in pastes on the color of all-ceramic veneers made by Ips-empress II system. METHODS: 50 discolored teeth were collected and restored with all-ceramic veneers. Five try-in pastes including A1, A3, transleucent(Trt), white opaque(WOT) and B0.5 opaque(B0.5),which were different in shade, were respectively used to try in before cementing. The color was measured by the ShadeEye, a digital colorimeter, and expressed in terms of 3 coordinate values (L*,a*,b*) of the CIEL*a*b* system. Then the color differences(deltaEa*b*) of all-ceramic veneers[deltaEa*b*=(deltaL*(2)+deltaa*(2)+deltab*(2))(1/2)] as well as the value of L*deltaC(ab)[C(ab)=(a*(2)+b*(2))(1/2)] and H(ab)[H(ab)=arctan(b*/a*)]were calculated. Meanwhile,the thickness of the measurement point was measured and recorded. One-way ANOVA was used to analyze deltaEa*b* as well as L*,C(ab) and Hab. RESULTS: The average thickness of the ceramic was 1.088mm, and the colour of the veneers after try in with WOT paste and B0.5 paste performed a higher L* value than the other pastes (P<0.05).And the veneers also showed a higher C(ab) value after try in with WOT,B0.5 and A3 paste than the A1 and Trt paste (P<0.05). No significant differences were found in Hab value after these 50 veneers tried in with these five kinds of pastes. CONCLUSIONS: It's more advisable to choose the WOT or the B0.5 luting agent to cement the veneer when the abutment tooth is severely discolored, while the Trt or the A1 shade and A3 shade luting resin may be more appropriate if the abutment tooth doesn't discolor or a little compared with the adjacent tooth.

[A preliminary study on the relationship between the wearing time of full denture and EMG in edentulous patients].

PURPOSE: This study was aimed to analyze the relationship between the periods of wearing time of full denture and function of mastication in edentulous patients. METHODS: Electromyogram (EMG) was done at an initial time of wearing full denture for 30 patients (Group A) and at an interval of wearing full denture for more than 3 months for 32 patients (Group B). EMG activities were recorded for 2 pairs of muscles (anterior temporalis, masseter) by means of Medelec Synergy Electromyography. Student's t test was used for statistical analysis. RESULTS: EMG amplitude of Group A was significantly lower than that of Group B (left anterior temporalis P < 0.05, bilateral masseter P < 0.05). Group A has larger area than Group B (P < 0.05); No significant difference was found in asymmetry index between Group A and Group B (P > 0.05). CONCLUSION: The function of mastication in patients who wore full denture for short time has not been achieved as expected.