1. Department of Head and Neck Surgery
2. Tokyo Medical and Dental University Graduate School of Medicine, Division of Head and Neck; Tokyo Japan
3. Cancer Institute Hospital, Japanese Foundation of Cancer Research, Department of Otolaryngology-Head and Neck Surgery; Tokyo Japan
4. Jichi Medical University, Shimotsuke, Japan, Department of Otolaryngology/Head and Neck Surgery Hamamatsu University School of Medicine; Hamamatsu Japan