1. Department of Otolaryngology–Head & Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
2. Department of Otolaryngology–Head & Neck Surgery, Hyogo Prefectural Amagasaki General Medical Center, Hyogo, Japan
3. Department of Head and Neck Surgery, Kanazawa Medical University, Ishikawa, Japan
4. Katsuragawa Mizuta ENT Clinic, Kyoto, Japan
5. Department of Otolaryngology–Head & Neck Surgery, Kurashiki Central Hospital, Okayama, Japan
6. Department of Otolaryngology–Head & Neck Surgery, Uji-Tokushukai Medical Center, Kyoto, Japan
7. Department of Otolaryngology–Head & Neck Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
8. Department of Otolaryngology–Head & Neck Surgery, Kobe City Medical Center General Hospital, Hyogo, Japan
9. Department of Otorhinolaryngology–Head & Neck Surgery, Shiga General Hospital, Shiga, Japan
10. Department of Otolaryngology–Head and Neck Surgery, Medical Research Institute, Kitano Hospital, Osaka, Japan
11. Department of Otolaryngology–Head & Neck Surgery, Kokura Memorial Hospital, Fukuoka, Japan
12. Department of Otorhinolaryngology–Head & Neck Surgery, Shizuoka General Hospital, Shizuoka, Japan