1. a Profesor Asociado, Departamento de Odontología Social, Universidad Peruana Cayetano Heredia, Lima, Peru; PhD Student, University College London, Epidemiology and Public Health, London, UK
2. b Clinical Lecturer, University College London, Epidemiology and Public Health, London, UK
3. c Postdoctorate Research in Orthodontics, University of Manchester, Dental School, Manchester, UK
4. d Emeritus Professor, University College of London, Department of Epidemiology and Public Health, London, UK