1. Department of Otolaryngology, Yamaguchi University Graduate School of Medicine
2. Department of Otorhinolaryngology & Psychiatry, Yoshida Hospital
3. Department of Otorhinolaryngology, Head & Neck Surgery, Faculty of Medicine, University of Miyazaki
4. Department of Otolaryngolog, Yamaguchi Rosai Hospital
5. Department of Otolaryngology - Head and Neck Surgery, Kitano hospital, Tazuke Kofukai Medical Research Institute Kyoto University, Graduate School of Medicine