1. Research Institute, Apple Tree Dental Hospital, Goyang-si, Gyeonggi-do, Korea
2. Department of Orthodontics, SMG-SNU Boramae Medical Center, Seoul, Korea
3. Department of Biostatistics, The Catholic University of Korea, College of Medicine, Seoul, Korea
4. Department of Oral and Maxillofacial Surgery, The Catholic University of Korea, Yeouido St. Mary’s Hospital, Seoul, Korea