1. Center of Dental Traumatology, Department of Conservative Dentistry and Periodontology, University Hospital Würzburg (UKW), Pleicherwall 2, 97070 Würzburg, Germany
2. Department of Cranio-Maxillofacial Surgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Gebäude W 30, 48149 Münster, Germany