1. Department of Otolaryngology – Head & Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan;
2. Department of Otolaryngology – Head & Neck Surgery, Kurashiki Central Hospital, Okayama, Japan;
3. Department of Otolaryngology – Head & Neck Surgery, Japanese Red Cross Osaka Hospital, Osaka, Japan;
4. Department of Otolaryngology – Head & Neck Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan;
5. Department of Otolaryngology – Head & Neck Surgery, Kobe City Medical Center General Hospital, Hyogo, Japan;
6. Department of Otolaryngology – Head & Neck Surgery, Medical Research Institute, Kitano Hospital, Osaka, Japan;
7. Department of Otorhinolaryngology – Head & Neck surgery, Shizuoka General Hospital, Shizuoka, Japan;
8. Department of Otolaryngology – Head & Neck Surgery, Hyogo Prefectural Amagasaki General Medical Center, Hyogo, Japan;
9. Department of Otolaryngology, Tenri Hospital, Nara, Japan;
10. Department of Otolaryngology, Japanese Red Cross Otsu Hospital, Shiga, Japan;
11. Department of Otolaryngology – Head & Neck Surgery, Kokura Memorial Hospital, Fukuoka, Japan;
12. Department of Otolaryngology, Japanese Red Cross Wakayama Medical Center, Wakayama, Japan