1. Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
2. Department of Head and Neck Surgery, National Hospital Organization, Kyushu Cancer Center, Fukuoka, Japan
3. Department of Head and Neck Surgery, Japan Community Health Care Organization, Kyushu Hospital, Kitakyushu, Japan
4. Department of Otorhinolaryngology, Hamanomachi Hospital, Fukuoka, Japan
5. Department of Otorhinolaryngology, Chidoribashi General Hospital, Fukuoka, Japan