1. Department of Otolaryngology—Head and Neck Surgery Oregon Health and Science University Portland Oregon U.S.A.
2. Department of Otolaryngology—Head and Neck Surgery University of Pittsburgh Medical Center Pittsburgh Pennsylvania U.S.A.
3. Department of Otolaryngology—Head and Neck Surgery Washington University School of Medicine in St. Louis St Louis Missouri U.S.A.
4. Department of Otolaryngology—Head and Neck Surgery Mayo Clinic Rochester Minnesota U.S.A.
5. Department of Otolaryngology—Head and Neck Surgery University Hospitals Cleveland Ohio U.S.A.
6. Department of Otolaryngology—Head and Neck Surgery University of California Davis Sacramento California U.S.A.
7. Department of Surgery Creighton University School of Medicine, Nebraska Methodist Hospital Omaha Nebraska U.S.A.
8. Department of Otolaryngology—Head and Neck Surgery University of Minnesota Minneapolis Minnesota U.S.A.
9. Department of Otolaryngology—Head and Neck Surgery Massachusetts Eye and Ear Boston Massachusetts U.S.A.
10. Department of Otolaryngology—Head and Neck Surgery John Hunter Hospital New Lambton Heights New South Wales Australia
11. Department of Otolaryngology—Head and Neck Surgery University of Cincinnati Cincinnati Ohio U.S.A.
12. Department of Neurosurgery Oregon Health and Science University Portland Oregon U.S.A.