[1] Univ Hosp Regensburg, Dept Cranio Maxillofacial Surg, D-93042 Regensburg, Germany
[2] Univ Regensburg, Inst Qual Management & Hlth Serv Res, Tumor Ctr, D-93053 Regensburg, Germany
[3] Univ Hosp Regensburg, Dept Otorhinolaryngol, D-93042 Regensburg, Germany
[4] Friedrich Alexander Univ Erlangen Nurnberg, Dept Internal Med Hematol Oncol 5, Hematol Oncol, D-91054 Erlangen, Germany
[5] Univ Hosp Regensburg, Dept Orthodont, D-93042 Regensburg, Germany
[6] St Elisabeth Hosp Straubing, Dept Otorhinolaryngol, D-94315 Straubing, Germany
[7] Univ Hosp Regensburg, Dept Plast & Reconstruct Surg, D-93042 Regensburg, Germany