1. Department of Otolaryngology, Hashima City Hospital
2. Division of Otolaryngology, Head and Neck Surgery, Nihon University School of Medicine
3. Department of Otolaryngology and Head and Neck Surgery, Ichinomiya West Hospital
4. Department of Otolaryngology, Central Japan International Medical Center
5. Department of Otolaryngology, Head and Neck Surgery, Gifu University Medical School