Un-Bong Baik1, Jae Hyun Park2, Yoon-Ah Kook3. 1. Private Practice of Orthodontics in Seoul, Korea. 2. Postgraduate Orthodontic Program, Arizona School of Dentistry and Oral Health, A.T. Still University. International Scholar, Graduate School of Dentistry, Kyung Hee University, Seoul. jpark@atsu.edu. 3. Department of Orthodontics, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul.