1. Department of Oral & Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, 9713 Groningen, The Netherlands
2. Department of Plastic, Reconstructive and Hand Surgery, Catharina Ziekenhuis Eindhoven, 5623 Eindhoven, The Netherlands
3. Department of Pathology & Medical Biology, University Medical Center Groningen, University of Groningen, 9712 Groningen, The Netherlands
4. Department of Plastic, Reconstructive and Hand Surgery, University Medical Center Utrecht, Utrecht University, 3584 Utrecht, The Netherlands