1 Department of Orthodontics, West China Hospital of Stomatology, Sichuan University & State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Chengdu 610041, China.
2 Department of Orthodontics, West China Hospital of Stomatology, Sichuan University & State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Chengdu 610041, China (Present address: Department of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University & The Key Laboratory of Oral Biomedicine, Jiangxi Province, Nanchang 330080, China).