[1] Univ Siena, Inst ENT Specialties, I-53100 Siena, Italy
[2] Publ Hlth Agcy, Rome, Italy
[3] Univ Milan, Inst Paediat, Milan, Italy
[4] Hosp Paediat, Working Grp, Milan, Italy
[5] Osped San Martino Genova, Reg Dept Head & Neck, Genoa, Italy
[6] Assoc Culturale Pediatri, Rome, Italy