1. Department of Orthodontics, School of Dentistry, University of Wonkwang, Iksan 54538, Republic of Korea
2. Postgraduate Orthodontic Program, Arizona School of Dentistry & Oral Health, A.T. Still University, Mesa, AZ 85206, USA
3. Graduate School of Dentistry, Kyung Hee University, Seoul 02453, Republic of Korea
4. Wonkwang Dental Research Institute, University of Wonkwang, Iksan 54538, Republic of Korea