1. Department of Otolaryngology, Tohoku Rosai Hospital, Dainohara, Aoba-ku, Sendai, Miyagi, Japan
2. Department of Otolaryngology, Tohoku Kosai Hospital, Kokubun-cho, Aoba-ku, Sendai-shi, Miyagi, Japan
3. Department of Otolaryngology—Head and Neck Surgery, Tohoku University Graduate School of Medicine, Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan