1. Department of Otorhinolaryngology-Head and Neck Surgery; Graduate School of Medicine; Chiba University; Chiba Japan
2. Department of Otorhinolaryngology-Head and Neck Surgery; University of Fukui; Fukui Japan
3. Department of Otolaryngology-Head and Neck Surgery; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan
4. Biostatistics Department; Shionogi & Co., Ltd.; Osaka Japan
5. Clinical Development Department; Shionogi & Co., Ltd.; Osaka Japan
6. Department of Otorhinolaryngology-Head and Neck Surgery; Graduate School of Medical Science; University of Yamanashi; Yamanashi Japan