1. Department of Orthodontics, School of Dentistry, Kanagawa Dental University, Yokosuka 238-8580, Japan
2. Department of Orthodontics, Pusan National University Dental Hospital, Yangsan 50612, Republic of Korea
3. Division of Orthodontics, College of Dentistry, University of Kentucky, Lexington, KY 40536, USA
4. Department of Orthodontics, Suez Canal University, Ismailia 41522, Egypt