1. Division of Orthodontics and Periodontics, Dental Department, Security Forces Hospital, Riyadh Colleges of Dentistry & Pharmacy, P.O. Box 84891, Riyadh 11681, Saudi Arabia
2. Department of Orthodontics, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY 14214-3008, USA
3. Division of Orthodontics, Department of Preventive Dental Science, Faculty of Dentistry, King Abdulaziz University, P.O. Box 80209, Jeddah 22254, Saudi Arabia