title: [Changes in the prevalence of dental caries in schoolchildren in three regions of Mexico: surveys from 1987-1988 and 1997-1998].
abstract: OBJECTIVE
  To compare the prevalence and severity of dental caries found in epidemiological surveillance studies conducted in three areas of Mexico in two different periods, 1987-1988 and 1997-1998.
  
  
  METHODS
  The 1987-1988 survey was done with representative samples of schoolchildren 6 to 10 years old in two states, Nuevo León and Tabasco, as well as in the country's Federal District (which includes Mexico City). The Federal District's 1987-1988 sample also included schoolchildren who were 12 years old. The total number of students examined in the 1987-1988 period was 7 590. The 1997-1998 survey included schoolchildren who were 6-10 years old and 12 years old, in all three of the areas. The total number of students included in the 1997-1998 survey was 8 164. To compare the prevalence and severity of dental caries in the two periods, the average value for the index of decayed, missing, and filled teeth (DMFT) was used with all of the age groups.
  
  
  RESULTS
  The values of the DMFT indices were significantly lower in the 1997-1998 period for all of the age groups studied (P < 0.05 for all the age groups). In the 1997-1998 period both Tabasco and Nuevo León achieved the goal recommended by the World Health Organization of an average of no more than three decayed, missing, and filled teeth among the 12-year-olds, with DMFT indices of 2.67 and 1.72, respectively. However, in the Federal District in that 1997-1998 period the DMFT index exceeded the recommended level, with a value of 3.11.
  
  
  CONCLUSIONS
  The reduction seen in the DMFT indices could be due to several factors, including the consumption of fluoridated salt, the use of dentifrices and fluoride rinses, and broader access to dental services.
authors.affiliation: Secretaría de Salud, San Luis Potosí #199, 9 degrees piso, Col. Roma CP 06700, México, D.F.
authors.forename: Oscar
authors.initials: O
authors.lastname: Velázquez Monroy
authors.forename: Heriberto
authors.initials: H
authors.lastname: Vera Hermosillo
authors.forename: María Esther
authors.initials: ME
authors.lastname: Irigoyen Camacho
authors.forename: Adriana
authors.initials: A
authors.lastname: Mejía González
authors.forename: Teresa Leonor
authors.initials: TL
authors.lastname: Sánchez Pérez
mesh_terms: D002648:Child; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D003752:Dental Health Services; D019229:Dentition, Permanent; D005260:Female; D006297:Health Services Accessibility / Q000639:trends; D006306:Health Surveys; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D009017:Morbidity / Q000639:trends; D015995:Prevalence; D012720:Severity of Illness Index; D014094:Tooth, Deciduous