1. Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Germany
2. Department of Neurosurgery, University of Witten/Herdecke, Cologne Merheim Medical Center (CMMC), Cologne, Germany
3. Department of Anatomy I, University of Cologne, Germany
4. Department of Orthopedics and Traumatology, University of Cologne, Germany
5. Bundeswehrzentralkrankenhaus, Koblenz, Germany
6. Department of Orthopaedics and Trauma Surgery, Helios Klinikum Siegburg, Germany