Study On The Influencing Factors Of Children’s Dental Fluorosis Prevalence In Drinking Water Fluorosis Area

Objectives:To understand the situation on the water quality and children’s dietary nutrient intakes, analyse the impact factors of children’s dental fluorosis after water improvement for water fluoride area.methods:Choose six villiges (water supply point) which water fluorine content is in< 0.8、0.8～、1.0～,1.2～,1.5～、more than 2.0～mg/l without drink ing-tea type and pollution of coal-burning fluorosis from Xiong county ang Linzhang county of Hebei, Feng county of Jiangsu, Jiaxiang cunty of Shandong by multi-stage random sampling.The source of water in the school where children attend is same with the villige.One water sample was gathered randomly from one household in the survey villige during investigation. Water quality and water fluoride concentration were detected with the drinking water standard test method. Checked the prevalence of denial fluorosis, calculated degree of dental fluorosis for 3043 children with with Dean’s method in 29 villages. Selected 10 ch i ldrcn demanded two chi 1 dren every age and one boy one girl from every survey villige to conduct dietary nutrition investigation in 3 days by duplicate portion study. Recorded dietary name of edible portion and weight and every chi Id’s daily drinking water amount, then mixed and homogenized, and selected all or part daily dietary of every child to dry and pack, then sent to the laboratory for detection of dietary fluoride contentrtion. Established the database using excel 2013. Calculated the intake of dietary nutrients for each child with chinese food composition table. Calculated the quality of drinking water, children daily water intake, dietary intakes and prevalence of dental fluorosis with SAS9.3. Based on the single factor regression analysis method to screen the impact factors of children’s dental fluorosis prevalence and degree with every exposure indicator as independent variable, dental fluorosis prevalence or dental fluorosis index as dependent variables. result:First:Basic situation. The average dental fluorosis prevalence rate of children aged 8 to 12 years was 30.2%, whose range is between 2.0% and 71.4%. The average index of dental fluorosis is 0.56,whose range is from 0.04 to 1.59; Collecting dietary of 270 children and detecting 789 samples of dietary, the average value and standard deviation of dietary fluroride is 4.69±2.1 lmg/kg。 Second:Single factor regression analysisIt has statistical significance that the single factor regression equation between water fluoride during investigation(WFDI) and dietary fluoride, WFDI and total fluoride intake, dietary fluoride and total fluoride intake. Their correlation coefficients are 0.46、0.82 and 0.59 respectively.The correlation coefficient(TCC) is from 0.5 to 0.6 between WFDI, village annual income per capita, dietary phosphorus and children’s dental fluorosis prevalence rate(DFPR).TCC is from 0.4 to 0.5 between water PH, dietary fluoride, carbohydrates, thiamin, total fluoride intake,water fluoride before the water improvement and copper of dietary and DFPR. TCC is from 0.35 to 0.4 between water chloride, dieary fluoride intake, zinc, VE,niacin, iron, protein and DFPR. It has statistical significance that the single factor regression equation between above index and DFPR.TCC is from 0.5 to 0.7 between vitamin E, carbohydrate, protein, WFDI, dietary intake of fluoride, village annual income per capita, water PH, dietary copper, niacin, dietary fluoride.dietary iron, dietary phosphorus and children’s dental fluorosis index(DFI). It is from 0.4 and 0.5 between di ssolved total solids, water fluoride before the water improvement, total fluoride intake, dietary zinc, dietary iron, total hardness, thiamine, sulfate and DFI.It is from 0.37 to 0.4 between riboflav, chloride and DFI. It has statistical significance that the single factor regression equation between above index and DFI.Third:Multiple linear regression analysis. It has statistical significance that the single factor regression equation between WFDI,water chloride, dietary fluoride, copper, zinc, protein, VE and DFPR of the children aged from 8 to 12 years old(F=10.98, P<0.0001, R2=0.786). The standard partial regression coefficients (SPRC) is 0.5497,0.4327,0.3298,1.4009,1.0233,-1.5374 and -0.6951 respectively. It has statistical significance that the single factor regression equation between fluoride, chloride of drinking water, fluoride, phosphorus, zinc, riboflav of dietary and DFI of the children aged from 8 to 12 years old(F=11.89, P<0.0001, R2=0.790). SPRC is 0.3570、0.5481、0.2626、0.8999、0.6621 and -0.9302 respectively.Conclusion:Many factors influence the children’s dental fluorosis prevalence. Besides water fluoride and dietary fluoride, there are also some water quality and dietary nutrient.Fluoride, chloride of water,fluoride, copper, zinc are risk fators for DFPR of children, protein and VE are protective factor. The increase of water fluoride,water chloride,dietary fluoride, phosphorus, zinc intake will aggravate the severity of dental fluorosis.The increase of dietary riboflav intake will reduse the severity of dental fluorosis.