[1] Univ North Carolina Chapel Hill, Dept Otolaryngol Head & Neck Surg, 170 Manning Dr,CB 7070,Phys Off Bldg, Chapel Hill, NC 27599 USA
[2] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Oral Diag, Div Radiol, Campinas, SP, Brazil
[3] Indiana Univ Sch Med, Riley Childrens Hosp, Dept Pediat, Sect Pediat Pulmonol Allergy & Sleep Med, Indianapolis, IN 46202 USA
[4] Univ North Carolina Chapel Hill, Dept Phys & Astron, Chapel Hill, NC USA
[5] Univ N Carolina, Craniofacial Ctr, Chapel Hill, NC USA