1. Department of Orthodontics, Institute of Translational Dental Sciences, Pusan National University, Busan, South Korea.
2. Department of Statistics, College of Natural Science, Pusan National University, Busan, South Korea.
3. Department of Orthodontics, Institute of Translational Dental Sciences, Pusan National University, Busan, South Korea; Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea; and Dental Research Institute, Pusan National University Dental Hospital, Busan, South Korea.