1. Department of Oral and Maxillofacial Surgery, Medical University of Vienna, Vienna, Austria
2. Department of Oral and Maxillofacial Surgery, University of Athens Medical School, Attikon Hospital, Athens, Greece
3. Department of Oral and Maxillofacial Surgery, Erlangen University Hospital, Erlangen, Germany
4. Department of Prosthodontics, Erlangen University Hospital, Erlangen, Germany