Kwangchul Choy, DDS, MS, PhD, is a former professor of the Orthodontics Department at Yonsei University. He completed his orthodontic training and earned his degree from the same university. He has worked as a research fellow and visiting professor at the University of Connecticut. Currently, he serves as a clinical professor at Yonsei University and an adjunct professor of Orthodontics at Ewha Womans University. He has authored a book titled "The Biomechanical Foundation of Clinical Orthodontics" and has published over 30 papers and book chapters on biomechanics. Dr. Choy has conducted extensive clinical and scientific research in the field of orthodontic biomechanics and is a frequent lecturer on the topic. He also runs a private practice in Seoul.