[1] AOU Osped San Martino, Dipartimento Patol Testa Collo, IT-16132 Genoa, Italy
[2] Univ Bari, Dipartimento Ocullist & Otorinolaringoiatria, Bari, Italy
[3] Univ Pavia, Policlin San Matteo, IRCCS, Pediat Clin, I-27100 Pavia, Italy
[4] Univ Pavia, Policlin San Matteo, IRCCS, Serv Biometria & Epidemiol Clin, I-27100 Pavia, Italy