1. Oral Pathology Department, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
2. TelessaudeRS-UFRGS, Federal Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
3. Postgraduate Programme in Epidemiology, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
4. Department of Oral Medicine, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Rio Grande do Sul, Brazil.