1. Department of Cranio and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
2. Department of Cranio and Maxillofacial Surgery, Heinrich Heine University of Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany
3. Department of Medical Psychology, Ruhr University of Bochum, Universitätsstr. 150, Building MA 0/145, 44780 Bochum, Germany