1. Department of Otolaryngology‐Head & Neck Surgery Japanese Red Cross Osaka Hospital Osaka Japan
2. Department of Otolaryngology‐Head & Neck Surgery Kyoto University Graduate School of Medicine Kyoto Japan
3. Department of Otolaryngology‐Head & Neck Surgery Uji‐Tokushukai Medical Center Kyoto Japan
4. Department of Otolaryngology‐Head & Neck Surgery National Hospital Organization Kyoto Medical Center Kyoto Japan
5. Department of Otolaryngology Japanese Red Cross Wakayama Medical Center Wakayama Japan
6. Minoyama Otolaryngology Medical Corporation Osaka Japan