title: Is the relative increase in income inequality related to tooth loss in middle-aged adults?
abstract: OBJECTIVE
  To assess whether Brazilian middle-aged adults living in cities that experienced a relative increase on income inequality were more likely to have severe tooth loss and lack a functional dentition.
  
  
  METHODS
  Data on Brazilian adults aged 35-44 years from state capitals and Federal District from the 2010 Brazilian Oral Health Survey (SBBrasil 2010) were analyzed. Clinically assessed tooth loss outcomes were severe tooth loss (<9 remaining natural teeth) and lack of functional dentition (<21 natural teeth). Income inequality was assessed by Gini Index in 1991, 2000, and 2003 using tertiles of distribution. Variation in Gini Index was assessed by changes in the tertiles distribution between years. Multilevel logistic regression models were used to estimate odds ratios (ORs) and 95 percent confidence intervals (95 percent CI) between variation in income inequality and tooth loss outcomes adjusting for individual socio-demographic characteristics.
  
  
  RESULTS
  Prevalence of severe tooth loss and lack of functional dentition was 4.8 percent and 21.2 percent, respectively. Individuals living in cities with moderate and high increase in income inequality between 1991 and 2003 were more likely to have severe tooth loss and lack a functional dentition in 2010 compared with those living in cities with stable income inequality in the same period. Relationships between low family income and both tooth loss outcomes were significantly attenuated by relative increases in income inequality.
  
  
  CONCLUSIONS
  Relative increases in income inequality were significantly associated with severe tooth loss and lack of a functional dentition in Brazilian middle-aged adults.
authors.affiliation: Department of Preventive and Social Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.|Unit of Dental Public Health, School of Clinical Dentistry, University of Sheffield, Sheffield, UK.
authors.forename: Mariél de Aquino
authors.initials: Mde A
authors.lastname: Goulart
authors.affiliation: Unit of Dental Public Health, School of Clinical Dentistry, University of Sheffield, Sheffield, UK.
authors.forename: Mario Vianna
authors.initials: MV
authors.lastname: Vettore
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D003753:Dental Health Surveys; D005260:Female; D006801:Humans; D007182:Income / Q000706:statistics & numerical data*; D008297:Male; D015995:Prevalence; D012959:Socioeconomic Factors; D016388:Tooth Loss / Q000453:epidemiology*
keywords: dental health surveys; multilevel analysis; social determinants of health; tooth loss