1. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics West China Hospital of Stomatology, Sichuan University Chengdu China
2. Department of Orthodontics and Pediatric Dentistry University of Michigan School of Dentistry Ann Arbor MI USA
3. Department of Orthodontics Intercontinental University Mexico City Mexico
4. University of Michigan School of Dentistry Ann Arbor MI USA