[1
]
Department of Otolaryngology, University of Tokushima School of Medicine, Tokushima
770-8503, Japan. Electronic address: azuma.takahiro@tokushima-u.ac.jp.
[2
]
Department of Otolaryngology, University of Tokushima School of Medicine, Tokushima
770-8503, Japan.
[3
]
Department of Otolaryngology, Tokushima Prefectural Central Hospital, Tokushima 770-8539,
Japan.
[4
]
Department of Otolaryngology, Kochi National Hospital, Kochi 780-8077, Japan.