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