1. Department of Otorhinolaryngology Head and Neck Surgery, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium
2. Department of Otorhinolaryngology Head and Neck Surgery, Hopital Moliere Longchamp, Brussel, Brussel, Belgium
3. Department of Surgery, University of Wisconsin-Madison Center for Health Systems Research and Analysis, Hollis, New Hampshire
4. Department of Plastic Surgery, University of Virginia, Charlottesville, Virginia
5. Division of Facial Plastic and Reconstructive Surgery, Stanford University School of Medicine, Stanford, California
6. Department of ENT, ENT Practice Moser Gehrking Sauter and Partner, Augsburg, Germany