1. Center for Surveillance and Epidemiology of Oral Diseases, Faculty of Dentistry University of Chile Santiago Chile
2. Department of Conservative Dentistry, Faculty of Dentistry University of Chile Santiago Chile
3. Consultorio General Rural de Camiña, Servicio de Salud Tarapacá Iquique Chile
4. School of Public Health, Faculty of Medicine University of Chile Santiago Chile
5. Centro para la Prevención y el Control del Cáncer, CECAN Santiago Chile