Affiliation: | 1. Department of Otorhinolaryngology ‐ Head and Neck Surgery, Keio University School of Medicine, Shinjuku, Tokyo, Japan;2. Department of Otorhinolaryngology ‐ Head and Neck Surgery, Kawasaki Municipal Kawasaki Hospital, Kawasaki, Kanagawa, Japan;3. Department of Otorhinolaryngology, Saiseikai Utsunomiya Hospital, Utsunomiya, Tochigi, Japan;4. Department of Otorhinolaryngology, Saiseikai Yokohamashi Nanbu Hospital, Yokohama, Kanagawa, Japan;5. Department of Otorhinolaryngology, Yokohama Municipal Citizen's Hospital, Yokohama, Kanagawa, Japan;6. Department of Otorhinolaryngology, Kyosai Tachikawa Hospital, Tachikawa, Tokyo, Japan;7. Department of Otorhinolaryngology, Saiseikai Yokohamashi Tobu Hospital, Yokohama, Kanagawa, Japan;8. Department of Otorhinolaryngology, Tokyo Saiseikai Central Hospital, Minato, Tokyo, Japan |