Dr. Xu is a professor of orthodontics at the Peking University School of Stomatology and an adjunct professor of Case Western Reserve University. He received his postgraduate education in orthodontics at Peking University School of Stomatology from 1988 to 1992 and was a Visiting Fellow in Orthodontics at the University of California San Francisco from 1994 to 1996. He serves on OCR and EJO editorial board and AJODO editorial review board. His research interests focus on 4D orthodontics and the investigation of clinical orthodontic outcomes.