1. Department of Oral and Maxillofacial Surgery, University Hospital Groningen, A. Deusinglaan 1, 9713, AV Groningen, The Netherlands
2. Department of Medical Microbiology, University of Liverpool, Liverpool, United Kingdom
3. Division of Oncology, Department of Surgery, University Hospital Groningen, A. Deusinglaan 1, 9713, AV Groningen, The Netherlands