1. Olga Polydorou, associate professor, DDS, Dr.med.dent, PD, Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Dental School and Hospital, Freiburg, Germany
2. Mira Wirsching, assistant, Dr.med,dent, Department of Orthodontics, University of Heidelberg, Heidelberg, Germany
3. Martin Wokewitz, scientific assistant, Dr.sc.hum, Institute of Medical Biometry and Medical Informatics, Albert-Ludwigs-University Freiburg, Freiburg, Germany
4. Petra Hahn, professor, Dr.med.dent, PD, Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Dental School and Hospital, Freiburg, Germany