“…2,[4][5][6]8, Most of the prevalence studies have been carried out in European and Asian countries; however, there have been several recent reports on this clinical topic in Latin American countries. For instance, Mexico, 11,[25][26][27]34 Brazil, 6,10,35,36 Chile, 13 Argentina/Uruguay, 16 and Colombia 23 ; the determined prevalence rates from these studies varied between 11.2 and 42.4 percent. Specifically, five studies have been conducted in México in well-definite and limited geographic zones, on school children from Mexico City and Naucalpan (Estado de México).…”