Dr. Yeong-Charng Yen currently is a clinical associate professor of the Orthodontic Department of the School of the Stomatology of the Taipei Medical University, Taipei, Taiwan. He has maintained a private practice at Taipei since 1988. He graduated from Taipei Medical University in 1976 and earned his M.D.S. degree from the University of Pittsburgh, PA, USA in 1987. He is a Diplomate of the Taiwan Board of Orthodontics, Diplomate of the American Board of Orthodontics and Fellow, the College of Diplomates of the American Board of Orthodontics.