[1] Univ Fed Rio Grande do Sul, Fac Med, Programa Posgrad Saude Crianca & Adolescente, Rua Ramiro Barcellos 2400, BR-90035003 Porto Alegre, RS, Brazil
[2] Univ Fed Rio Grande do Sul, Sch Med, Programa Posgrad Saude Crianca & Adolescente, Laryngol Unit,Dept Otolaryngol,HCPA, Porto Alegre, RS, Brazil
[3] Univ Fed Rio de Janeiro UFRJ, HCPA, Dept Radiol, Porto Alegre, RS, Brazil
[4] HCPA, Dept Otolaryngol, Porto Alegre, RS, Brazil
[5] Univ Fed Rio Grande do Sul, Fundacao Univ Cardiol Rio Grande Sul, Sch Speech Language Pathol & Audiol, Porto Alegre, RS, Brazil
[6] Univ Fed Rio Grande do Sul, Sch Med, Programa Posgrad Saude Crianca & Adolescente, Pediat Pulmonol Unit,Dept Pediat,HCPA, Porto Alegre, RS, Brazil