Satoru Kodama1, Masashi Suzuki2. 1. Department of Otolaryngology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hazama-machi, Yufu, Oita, 879-5593, Japan. satoruk@med.oita-u.ac.jp. 2. Department of Otolaryngology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hazama-machi, Yufu, Oita, 879-5593, Japan.