Kiyoshi Tai1, Jae Hyun Park2. 1. Postgraduate Orthodontic Program and Graduate School of Dentistry, Kyung Hee University, Seoul, South Korea. 2. Postgraduate Orthodontic Program, Arizona School of Dentistry and Oral Health, A.T. Still University, Mesa, AZ, USA, and Graduate School of Dentistry, Kyung Hee University, Seoul, South Korea. jpark@atsu.edu.