1. Master degree student, Department of Oral Pathology; School of Dentistry; Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
2. Assistant professor, Department of Oral Pathology, School of Dentistry; Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
3. Assistant professor, Department of Stomatology of Hospital de Clínicas de Porto Alegre; Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil