1. Department of Oral and Maxillofacial Surgery; University Medical Center; Mainz Germany
2. Department of Oral and Maxillofacial Plastic Surgery; University of Cologne; Cologne Germany
3. Department of Operative Dentistry and Periodontology; University Medical Center; Mainz Germany
4. Department of Periodontology; Victor Babes University of Medicine and Pharmacology; Timisoara Romania
5. Institute of Functional and Clinical Anatomy; University Medical Center; Mainz Germany