1. Department of Otolaryngology, Head and Neck Surgery, Wakayama Medical University, Wakayama, Japan
2. Kamide ENT Clinic, Shizuoka, Japan
3. Nonohana Clinic, Yamaguchi, Japan
4. Uno ENT Clinic, Okayama, Japan
5. Chiba College of Public Health, Chiba, Japan
6. Department of Otolaryngology, Head and Neck Surgery, Kanazawa University, Kanazawa, Japan
7. Department of Otolaryngology, Head and Neck Surgery, Hirosaki, University, Hirosaki, Japan
8. Sugita ENT Clinic, Chiba, Japan