1. Department of Otorhinolaryngology, National Hospital Organization Osaka National Hospital, Houenzaka, Osaka City, Osaka, Japan
2. Department of Otorhinolaryngology–Head and Neck Surgery, Osaka University Graduate School of Medicine, Suita City, Osaka, Suita City, Japan
3. Department of Otolaryngology, Kindai University Faculty of Medicine, Osakasayama City, Osaka, Oonohigashi, Sayama City, Osaka, Japan