1. Department of Oral Medicine and Peridontology, Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt.
2. Department of Prosthodontics, Ain Shams University Faculty of Dentistry, Cairo, Egypt.
3. Department of Oral and Maxillofacial Radiology, Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt.
4. Department of Periodontology, Ain Shams University and October 6th University, Faculty of Dentistry, Cairo, Egypt.
5. Department of Periodontology, School of Dental Medicine, Stony Brook University, Stony Brook, New York, USA.