[1] Chinese Univ Hong Kong, Dept Otorhinolaryngol Head & Neck Surg, Hong Kong, Peoples R China
[2] Yonsei Univ, Coll Med, Dept Otorhinolaryngol, Seoul, South Korea
[3] Harvard Med Sch, Massachusetts Eye & Ear Infirm, Dept Otolaryngol Head & Neck Surg, Boston, MA 02115 USA
[4] Soonchunhyang Univ Hosp, Coll Med, Dept Otorhinolaryngol Head & Neck Surg, Seoul, South Korea
[5] Stanford Univ, Dept Otolaryngol, Div Head & Neck Surg, Palo Alto, CA 94304 USA
[6] Siam Univ, Fac Med, Police Gen Hosp, Dept Surg, 492-1 Rama I Rd, Bangkok 10330, Thailand