1. Section Head of Endodontics, Department of Applied Dental Medicine Southern Illinois University School of Dental Medicine Alton Illinois USA
2. Section of Oral and Maxillofacial Surgery, Department of Applied Dental Medicine Southern Illinois University School of Dental Medicine Alton Illinois USA
3. Applied Dental Medicine Department, Section of Periodontics Southern Illinois University School of Dental Medicine Alton Illinois USA
4. Division of Geriatric Medicine, St. Louis VA Medical Center Washington University School of Medicine Saint Louis Missouri USA
5. Washington University School of Medicine Saint Louis Missouri USA
6. Southern Illinois University School of Dental Medicine Alton Illinois USA