1. Department of Orthodontics; Dental Research Institute; Pusan National University Dental Hospital; Yangsan South Korea
2. Department of Statistics; College of Natural Science; Pusan National University; Busan South Korea
3. Department of Orthodontics; School of Dentistry; University of North Carolina; Chapel Hill NC USA
4. Institute of Translational Dental Sciences; Pusan National University; Yangsan South Korea