1. Section of Periodontology; Department of Conservative Dentistry; Clinic for Oral, Dental and Maxillofacial Diseases; University Hospital Heidelberg; Heidelberg Germany
2. Private Practice; Bielefeld Germany
3. Private Practice; Hamburg Germany
4. Institute of Medical Biometry and Informatics (IMBI); University Hospital Heidelberg; Heidelberg Germany
5. Department of Oral- and Cranio-Maxillofacial Surgery; Clinic for Oral, Dental and Maxillofacial Diseases; University Hospital Heidelberg; Heidelberg Germany
6. Department of Periodontology; Center of Dentistry and Oral Medicine (Carolinum); Johann Wolfgang Goethe-University; Frankfurt Germany