1. Oral Medicine, Pathology and Laser-assisted Surgery Unit; University of Parma; Parma Italy
2. Department of Pathology and Laboratory Medicine; Microbiology Unit; University of Parma; Parma Italy
3. Department of Stomatology; Units of Oral Medicine and Oral and Maxillofacial Pathology; Dental Clinic Service; University of the Basque Country/EHU; Leioa Vizcaya Spain
4. Department of Oral Medicine; Centre for Oral Health Research, Newcastle University; Newcastle upon Tyne UK
5. Melbourne Dental School; The University of Melbourne; Melbourne Vic. Australia