[1] Univ Fed Rio Grande do Sul UFRGS, Grad Program Surg, Porto Alegre, RS, Brazil
[2] Hosp Mae de Deus, Otolaryngol Serv, Porto Alegre, RS, Brazil
[3] Univ Fed Rio Grande do Sul, Sch Med, Porto Alegre, RS, Brazil
[4] Santa Casa Misericordia Sao Paulo, Otolaryngol Serv, Sao Paulo, SP, Brazil
[5] Hosp Clin Porto Alegre HCPA, Otolaryngol Serv, Porto Alegre, RS, Brazil