1. Department of Otorhinolaryngology - Head and Neck Surgery, Osaka Medical College
2. Department of Otolaryngology, First Towakai Hospital
3. Department of otolaryngology, Tokai University School of Medicine
4. Department of Otolaryngology, Hirakata City Hospital
5. Department of Otolaryngology, Head and Neck Surgery, Rakuwakai Otowa Hospital