1. From the Department of Otorhinolaryngology, Plastic Head and Neck Surgery, St. Anna Hospital, Duisburg (Drs Windfuhr and Remmert), Duisburg and Aachen, Germany
2. From The Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital of Aachen, Aachen, Germany (Dr Chen), Duisburg and Aachen, Germany