CV
Dr Xu is a professor of orthodontics at the Peking University School of Stomatology and an adjunct professor of Case Western Reserve University. He was a visiting fellow in the Orthodontic Department at the University of California San Francisco from 1994 to 1996. He serves on the OCR (Orthodontic & Craniofacial Research) and EJO (European Journal of Orthodontics) editorial boards and the AJODO (American Journal of Orthodontics & Dentofacial Orthopedics) editorial review board. He is also a councillor of WFO (World Federation of Orthodontists).
Class II Correction-Functional Appliance or PAC (Physiologic Anchorage Control) Appliance?
How to correct Class II malocclusions? Users of headgear believe that we should prohibit the forward growth of the maxilla, whereas those of functional appliances advocate for promoting the forward growth of the mandible. Meanwhile, practitioners of fixed appliances concentrate on pushing the upper molars backward and pulling the lower molars forward to correct the distal molar relationship. As long as the molars achieve a neutral relationship, all of the aforementioned methods have been demonstrated to be effective, thereby reinforcing the beliefs of their respective proponents. If all of these strategies yield comparable final results, what is the underlying mechanism for Class II correction? Based on the studies on craniofacial growth and occlusal development, this lecture provides a novel orthodontic technique that simplify the Class II correction.
Learning objectives
- After taking this lecture you will learn the effect of mandible growth on upper molars
- After taking this lecture you will learn the mechanism of how functional appliance correct Class II molar relationship
- After taking this lecture you will learn the effect of straight-wire appliance itself on molar relationship
- After taking this lecture you will learn how PAC appliance correct Class II molar relationship
Orthodontic bracket: 3D prescription or 4D prescription?
The original prescription of straight wire appliance is based on adult’s normal data measured from study casts of optimal occlusion collected in USA. Although modifications based on mechanics or different races have brought different tips and torques prescription, less attention has given to the effects of growth changes of dentition. What if adolescent’s normal data is much different from adult’s normal? This lecture based on studies of occlusion development from a historical longitudinal growth sample with metallic implants and a prospective randomized clinical trial focus on molar anchorage control with a sample treated with MBT straight wire appliance will give a new perspective of bracket prescription. Instead of using 3D normal data from adult’s optimal occlusion that is certainly a one-time-point data, this lecture will introduce a new strategy that we call 4D bracket prescription dealing with changing angles of developing dentition, which could simplify anchorage control technique in extraction orthodontic treatment and provide a new strategy to relieve mild crowding or protrusion of dentition in non-extraction orthodontic treatment.
Learning objectives
- After taking this lecture you will know how buccal teeth grow during adolescence
- After taking this lecture you will know what will happen if using buccal tube with adult’s normal
- After taking this lecture you will know what precaution should be taken if using straight wire appliance
- After taking this lecture you will learn a new 4D strategy to strengthen anchorage without headgear or TAD for extraction orthodontic treatment