1. Oral Medicine Unit; Departamento de Clínica e Odontologia Preventiva; Universidade Federal de Pernamuco; Recife Brazil
2. Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche; Università degli Studi di Milano; Milan Italy
3. Discipline of Oral and Maxillofacial Surgery; Faculty of Dentistry; National University of Singapore; Singapore Singapore
4. WHO Collaborating Centre for Oral Health-General Health; UCL; London UK