1. Stomatology Center, Shenzhen Hospital Southern Medical University Shenzhen China
2. Department of Stomatology Northwest Women's and Children's Hospital Xi'an China
3. State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology Fourth Military Medical University Xi'an China
4. Department of Stomatology General Hospital of Tibetan Military Command Lhasa China
5. Department of Obstetrics Northwest Women's and Children's Hospital Xi'an China