1. State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Paediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
2. Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
3. Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
4. Department of Stomatology, Sichuan Provincial People’s Hospital, Chengdu 610041, China