1. Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Aichi, Japan
2. Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Aichi, Japan
3. Department of Rehabilitation, Kansai University of Welfare Science, Kashiwara 582-0026, Osaka, Japan