1 Department of Otorhinolaryngology, International University of Health and Welfare School of Medicine, Narita, Japan.
2 Department of Otorhinolaryngology, International University of Health and Welfare School of Medicine, Narita, Japan. Electronic address: 19m3019@g.iuhw.ac.jp.
3 Department of Otolaryngology-Head and Neck Surgery, Kawasaki Medical School, Okayama, Japan.
4 Department of Otolaryngology-Head & Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
5 Department of Otorhinolaryngology, Himeji St. Mary's Hospital, Himeji, Japan.
6 Department of Otorhinolaryngology, International University of Health and Welfare School of Medicine, Narita, Japan; Department of Otolaryngology-Head & Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.