[1] Univ Antwerp, Univ Antwerp Hosp, B-2020 Antwerp, Belgium
[2] St Lucas Gen Hosp, Dept Otorhinolaryngol, Ghent, Belgium
[3] St Luc Univ Hosp, Dept Otorhinolaryngol, Brussels, Belgium
[4] Univ Hosp Free Univ, Dept Otorhinolaryngol, Brussels, Belgium
[5] Heilig Hart Gen Hosp, Dept Otorhinolaryngol, Roeselare, Belgium
[6] CHU Sart Tilman, Dept Otorhinolaryngol, B-4000 Liege, Belgium
[7] Clin St Elizabeth, Dept Otorhinolaryngol, Namur, Belgium