1. Department of Pediatric Dentistry and Orthodontics; Faculty of Dentistry; University of São Paulo; São Paulo Brazil
2. Department of Pediatric Dentistry and Orthodontics; Faculty of Dentistry; Federal University of Minas Gerais; Belo Horizonte Minas Gerais Brazil
3. Department of Epidemiology and Public Health; University College London 1-19 Torrington Place; London UK