1. Department of Oral Pathology School of Dentistry Federal University of Rio Grande do Sul Porto Alegre Brazil
2. Department of Oral Medicine Porto Alegre Clinics Hospital (HCPA/UFRGS) Porto Alegre Brazil
3. Department of Oral Diagnosis Piracicaba Dental School University of Campinas Piracicaba Brazil
4. Experimental Pathology Unit Clinics Hospital of Porto Alegre Federal University of Rio Grande do Sul Porto Alegre Brazil
5. Laboratory of Epithelial Biology Department of Periodontics and Oral Medicine University of Michigan School of Dentistry Ann Arbor MI USA