Department of Otolaryngology—Head and Neck Surgery, Second Hospital, Jilin University, Changchun, China

Address correspondence and reprint requests to Guo-Fang Guan, MD, Department of Otolaryngology—Head and Neck Surgery, Second Hospital, Jilin University, 218 Ziqiang Street, Changchun 130041,China; E-mail: [email protected]

The authors report no conflicts of interest.