1. Department of Otolaryngology—Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
2. Department of Otolaryngology—Head and Neck Surgery, University of Washington, Seattle, Washington, USA
3. Otolaryngology—Head and Neck Surgery Service, Winn Army Community Hospital, Ft Stewart, Georgia, USA
4. Department of Otolaryngology/Head and Neck Surgery, Sint Lucas Andreas Ziekenhuis, Amsterdam, Netherlands
5. Department of Otolaryngology & Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
6. Department of Otolaryngology—Head and Neck Surgery, Washington University School of Medicine, St Louis, Missouri, USA