1. Department of Oral and Maxillofacial Surgery at the Klinikum Rechts Der Isar; Technische Universität München; Munich Germany
2. Department of Restaurative Dentistry; Ludwig-Maximilians-Universität München; Munich Germany
3. Department of Periodontology; University of Berne; Berne Switzerland
4. Anatomische Anstalt der Ludwig-Maxilimians-Universität München; Munich Germany