1. School of Medicine and Dentistry; University of Santiago de Compostela; Santiago de Compostela Spain
2. Medical-Surgical Dentistry Research Group (OMEQUI); Health Research Institute of Santiago de Compostela (IDIS); University of Santiago de Compostela; Santiago de Compostela Spain
3. Department of Medicine and Oral Surgery; University Institute of Health Sciences (IUCS), CESPU; Gandra Portugal
4. Department of Oral Medicine; King's College; London UK
5. WHO Collaborating Centre for Oral Cancer; London UK