1. Ministry of Health, Makkah, Saudi Arabia. P.O. Box 4137, Makkah 24359, Saudi Arabia
2. Orthodontic Department, Faculty of Dentistry, King Abdulaziz University, P.O. Box 80209, Jeddah 21589, Saudi Arabia
3. Orthodontic Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
4. Alfarabi Private College for Dentistry and Nursing, P.O. Box 23643, Jeddah 21589, Saudi Arabia