1. Department of Surgical Sciences, Section of Otorhinolaryngology and Head & Neck Surgery, Uppsala University, Uppsala, Sweden;
2. Department of Otorhinolaryngology – Head & Neck Surgery, Karolinska University Hospital, Stockholm, Sweden;
3. Department of Physiotherapy, Karolinska University Hospital, Stockholm, Sweden;
4. Department of Oncology – Statistics, Karolinska University Hospital, Stockholm, Sweden