[1] Int Goodwill Hosp, Otorhinolaryngol, Yokohama, Kanagawa, Japan
[2] Ota Mem Sleep Ctr, Kawasaki, Kanagawa, Japan
[3] Jikei Univ, Sch Med, Otorhinolaryngol, Tokyo, Japan
[4] Toho Univ, Ohashi Med Ctr, Otorhinolaryngol, Tokyo, Japan
[5] Toho Univ, Oomori Med Ctr, Otorhinolaryngol, Tokyo, Japan