1. From the Clinic of Otorhinolaryngology-Head and Neck Surgery (Drs Quante and Klußmann), University of Cologne, Cologne, Germany
2. From the Department of Dentistry (Dr Knoedgen), University of Cologne, Cologne, Germany
3. From the Department of Otorhinolaryngology of the General Hospital of Klagenfurt, Klagenfurt, Austria (Dr Eckel).