1. Division of Oral Medicine; Oral Diagnostic Sciences Department; Faculty of Dentistry; King Abdulaziz University; Jeddah Saudi Arabia
2. Department of Oral Medicine and Periodontology; Faculty of Oral and Dental Medicine; Cairo University; Cairo Egypt
3. Department of Oral Medicine and Periodontology; Faculty of Dentistry; October University for Modern Sciences and Arts; 6th October City Egypt
4. Department of Medical Biochemistry; Faculty of Medicine; Cairo University; Cairo Egypt
5. Emeritus Professor; UCL; London UK