1. Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
2. Department of Otorhinolaryngology, Kariya Toyota General Hospital, 5-15 Sumiyoshi-cho, Kariya-city, Aichi 448-8505, Japan
3. Department of Plastic and Reconstructive Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
4. Department of Computer Science and Electronics, Kyushu Institute of Technology, 680-4 Kawazu Iizuka-city, Fukuoka 820-8502, Japan