1. Department of Endodontics, College of Dentistry Tanta University Tanta Egypt
2. Department of Environmental and Radiological Health Sciences Colorado State University Fort Collins Colorado USA
3. Department of Statistics, Mathematics and Insurance, Faculty of Commerce Tanta University Tanta Egypt
4. Madinat Khalifa Health Centre Primary Health Care Corporation Doha Qatar
5. Department of Maxillofacial Surgery and Diagnostic Sciences College of Dentistry, Jazan University Jazan Saudi Arabia
6. Department of Oral Medicine, Oral Pathology and Oral Radiology Faculty of Dentistry, Sana'a University Sana'a Yemen