[1] Stanford Univ, Dept Otolaryngol Head & Neck Surg, Palo Alto, CA USA
[2] Univ Wisconsin, Sch Med & Publ Hlth, Div Otolaryngol Head & Neck Surg, Madison, WI 53706 USA
[3] 801 Welch Rd, Palo Alto, CA 94304 USA
[4] Univ Wisconsin, Dept Pediat, Sch Med & Publ Hlth, K4-719 Clin Sci Ctr,600 Highland Ave, Madison, WI 53792 USA