1. Division of Otolaryngology–Head and Neck Surgery, University of California–Los Angeles, School of Medicine, Los Angeles, California
2. Department of Otolaryngology, University of Colorado School of Medicine, Aurora, Colorado
3. Department of Otorhinolaryngology–Head and Neck Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
4. Division of Otolaryngology–Head and Neck Surgery, University of Arizona, Tucson, Arizona