1. Department of Otolaryngology–Head and Neck Surgery, Vanderbilt University, Nashville, Tennessee, USA
2. Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland, USA
3. Department of Otolaryngology–Head and Neck Surgery, Clinica Las Condes, Santiago Chile
4. Department of Pediatrics, Medicine Faculty, University of Chile, Santiago, Chile