title: Primary tooth fluorosis and fluoride intake during the first year of life.
abstract: OBJECTIVE
  Few studies in North America have assessed dental fluorosis of the primary dentition and few, if any, anywhere have assessed the relative importance in fluorosis etiology of fluoride intake during different time periods or from multiple sources. The purpose of this paper is to report on analyses relating estimated prenatal fluoride intake and fluoride intake during different parts of the first year of life to primary tooth fluorosis.
  
  
  METHODS
  As part of The Iowa Fluoride Study, subjects were recruited at birth and studied longitudinally. Trained examiners assessed dental fluorosis for children aged 4-7 years using the Tooth Surface Index of Fluorosis (TSIF) adapted for the primary dentition. Detailed parent questionnaires at childbirth were used to estimate prenatal fluoride intake and questionnaires sent at 6 weeks and 3, 6, 9, and 12 months were used to estimate fluoride intake during the first year of life (combined fluoride intake from water, food and beverage, supplements, and dentifrice). There were 504 children with prenatal and at least four of the five postnatal responses with complete data.
  
  
  RESULTS
  Fluorosis prevalence was 12.1%, occurring primarily on the second primary molars. Receiver operating characteristic (ROC) curves and logistic regression were used to assess the importance of different time periods' fluoride intake. In bivariate analyses, fluoride intake during each time interval was individually significantly related to fluorosis occurrence. For multivariate analyses, the period from 6 to 9 months was most important individually (P = 0.0001), and no other period was jointly statistically significant.
  
  
  CONCLUSIONS
  Results suggest that the middle of the first year of life is most important in fluorosis etiology for the primary dentition in this setting.
authors.affiliation: Department of Preventive and Community Dentistry, University of Iowa College of Dentistry, Iowa City, IA 52242, USA. steven-levy@uiowa.edu
authors.forename: Steven M
authors.initials: SM
authors.lastname: Levy
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Hillis
authors.forename: John J
authors.initials: JJ
authors.lastname: Warren
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Broffitt
authors.forename: A K M
authors.initials: AK
authors.lastname: Mahbubul Islam
authors.forename: James S
authors.initials: JS
authors.lastname: Wefel
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kanellis
mesh_terms: D019540:Area Under Curve; D002327:Cariostatic Agents / Q000008:administration & dosage* / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003710:Demography; D003802:Dentifrices; D019587:Dietary Supplements; D005260:Female; D005457:Fluoridation; D005459:Fluorides / Q000008:administration & dosage* / Q000009:adverse effects*; D009050:Fluorosis, Dental / Q000453:epidemiology / Q000209:etiology*; D005502:Food; D006801:Humans; D007223:Infant; D007484:Iowa / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D015995:Prevalence; D012372:ROC Curve; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D014094:Tooth, Deciduous
chemical_list: D002327:Cariostatic Agents; D003802:Dentifrices; D005459:Fluorides