[1] Univ Groningen Hosp, Dept Oral & Maxillofacial Surg, NL-9700 RB Groningen, Netherlands
[2] Univ Groningen Hosp, Dept Rehabil, Groningen, Netherlands
[3] Univ Groningen Hosp, Dept Otorhinolaryngol, NL-9700 RB Groningen, Netherlands
[4] Univ Groningen Hosp, Dept Surg Oncol, NL-9700 RB Groningen, Netherlands