1. Department of Oral and Cranio-Maxillofacial Surgery, Heidelberg University Hospital, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
2. Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
3. Institute of Medical Biometry, Heidelberg University Hospital, Im Neuenheimer Feld 130.3, D-69120 Heidelberg, Germany