1. Department of Oral and Maxillofacial Surgery; Corporate Member of Freie Universität Berlin; Humboldt-Universität zu Berlin; Berlin Institute of Health; Universitätsmedizin Berlin; Berlin Germany
2. Department of Oral and Maxillofacial Surgery; University Medical Centre Mainz; Mainz Germany
3. Department of Oral and Maxillofacial Surgery; Helios Kliniken Schwerin; Schwerin Germany
4. Department of Oral and Maxillofacial Surgery; University Medical Centre Rostock; Rostock Germany