1. Department of Plastic Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
2. Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
3. Department of Otorhinolaryngology, Rijnstate Hospital, Arnhem, The Netherlands.
4. Department of Rehabilitation Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
5. Department of Oral and Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.