OBJECTIVETo investigate the status of deciduous dental caries among preschool children in Chongqing city and to compare the oral health status of preschoolers from public and private kindergarten.

METHODSAccording to the criteria recommended by The Third National Oral Health Investigation, the deciduous caries of 5 030 preschool children aged 3 to 6 years old from 40 private kindergartens and 16 public kindergartens in Yuzhong district of Chongqing were examined. The prevalence of dental caries and the mean dmft and filling rate were calculated. The results were analyzed using SPSS 21.0 software package.

RESULTSMaxillary deciduous central incisors and mandibular deciduous molar were most prone to decay in 5,030 children. The prevalence of dental caries was 54.08% (2,720/5,030). The mean dmft score was 2.58 and the filling rate was 0.98% (127/12,993). The prevalence of dental caries and mean dmft increased gradually as the children were growing up (P < 0.05). The rate of filling teeth of the 6 year old group was higher than other groups (P < 0.05). No significant difference between males and females were noted (P > 0.05). The prevalence rate of deciduous dental caries among private kindergartens was 61.04% (1,656/2,713), with a mean dmft of 3.12 and filling rate of 0.35% (30/8,465). The prevalence rate of deciduous dental caries among public kindergartens was 45.92% (1,064/2,317), with a mean dmft of 1.95 and filling rate of 2.14% (97/4,528). Statistical analysis revealed significant differences in the prevalence rate, mean dmft, and filling rate between two kinds of kindergarten (P < 0.05).

CONCLUSIONDeciduous dental caries of preschool children is an important problem in Chongqing city and the children from private kindergarten had very low filling rate.

Child ; Child, Preschool ; China ; DMF Index ; Dental Caries ; Dental Pulp Cavity ; Female ; Humans ; Incisor ; Male ; Molar ; Oral Health ; Prevalence ; Tooth, Deciduous

Objective To investigate the status of dental caries of deciduous teeth among preschool children from private kin-dergarten in Chongqing city.Methods According to the criteria recommended by The Third National Oral Health Investigation,the deciduous caries of 2 713 preschool children aged 3 to 6 years from 40 private kindergartens in Yuzhong district were examined.The prevalence of dental caries and the mean dmft were calculated.The results were analyzed using SPSS21.0 software package. Results The prevalence of dental caries was 61.04%.The mean dmft score was 3.12,the filling rate was 0.4%.The caries preva-lence of 3-,4-,5-,6-year-old children were found to be 42.51%,59.53%,67.76% and 74.85%,and the mean dmft score were 2. 71,3.68,3.96 and 4.09.The prevalence of dental caries and mean dmft increased gradually as the children was statistically signifi-cant(P <0.05).The caries prevalence of male and female children were 61.65% and 60.41%,the mean dmft were 3.11 and 3.13, the difference was not statistically significant (P >0.05).Conclusion Deciduous dental caries of preschool children from private kindergartens was an important problem in Chongqing city,and the filling rate was very low.

OBJECTIVE: To assess the effects of varying the number of diffusion gradient directions (NDGDs) on diffusion tensor fiber tracking (FT) in human brain white matter using tract characteristics. MATERIALS AND METHODS: Twelve normal volunteers underwent diffusion tensor imaging (DTI) scanning with NDGDs of 6, 11, 15, 21, and 31 orientations. Three fiber tract groups, including the splenium of the corpus callosum (CC), the entire CC, and the full brain tract, were reconstructed by deterministic DTI-FT. Tract architecture was first qualitatively evaluated by visual observation. Six quantitative tract characteristics, including the number of fibers (NF), average length (AL), fractional anisotropy (FA), relative anisotropy (RA), mean diffusivity (MD), and volume ratio (VR) were measured for the splenium of the CC at the tract branch level, for the entire CC at tract level, and for the full brain tract at the whole brain level. Visual results and those of NF, AL, FA, RA, MD, and VR were compared among the five different NDGDs. RESULTS: The DTI-FT with NDGD of 11, 15, 21, and 31 orientations gave better tracking results compared with NDGD of 6 after the visual evaluation. NF, FA, RA, MD, and VR values with NDGD of six were significantly greater (smallest p = 0.001 to largest p = 0.042) than those with four other NDGDs (11, 15, 21, or 31 orientations), whereas AL measured with NDGD of six was significantly smaller (smallest p = 0.001 to largest p = 0.041) than with four other NDGDs (11, 15, 21, or 31 orientations). No significant differences were observed in the results among the four NDGD groups of 11, 15, 21, and 31 directions (smallest p = 0.059 to largest p = 1.000). CONCLUSION: The main fiber tracts were detected with NDGD of six orientations; however, the use of larger NDGD (> or = 11 orientations) could provide improved tract characteristics at the expense of longer scanning time.
Adult ; Anisotropy ; Diffusion Tensor Imaging/*methods ; Female ; Humans ; Male ; White Matter/*radiography ; Young Adult