1. Department of Orthodontics, University of Münster, 48149 Münster, Germany
2. Department of Orthodontics, Hannover Medical School (MHH), 30625 Hannover, Germany
3. Private Practice, 49152 Bad Essen, Germany
4. Department of Cranio-Maxillofacial Surgery, University of Münster, 48149 Münster, Germany