1. Division of Periodontics; Department of Stomatology; School of Dentistry; University of São Paulo; São Paulo SP Brazil
2. Department of Periodontology; Dental Research Division; Guarulhos University; Guarulhos SP Brazil
3. School of Dental Sciences and Institute of Cellular Medicine; Newcastle University; Newcastle upon Tyne UK
4. Institute of Epidemiology & Preventive Medicine; National Taiwan University; Taipei Taiwan