1. Department of Dento- and Maxillofacial Surgery; University of Ulm; Ulm Germany
2. Histologic and Embryologic Sciences; Department of Periodontology; Istanbul University; Istanbul Turkey
3. Institute of Dentistry; Turku University; Turku Finland
4. Department of Conservative Dentistry & Periodontology; University of Mainz; Mainz Germany
5. Department of Conservative Dentistry & Periodontology; University of Tübingen; Tübingen Germany
6. Medical Psychology Division; University Hospital of Psychosomatic Medicine and Psychotherapy; University of Ulm; Ulm Germany