1. Department of Periodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
2. Department of Oral Medicine and Periodontology, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
3. Department of Oral Medicine and Periodontics, Faculty of Dentistry, Alexandria University, Bab Sharqi, Alexandria Governorate 5424041, Egypt