1. 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 Implant DentistrySchool of Stomatology, The Fourth Military Medical University Xi'an China
2. Department of Biochemistry and Molecular BiologyCenter for DNA Typing, Air Force Medical University, 169 Changle West Road, Xi'an, Shaanxi 710032 P.R. China
3. Peking University, School of Stomatology Beijing China
4. State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Clinical Research Center for Oral Diseases, Department of Oral Disease, School of StomatologyThe Fourth Military Medical University Xi'an China
5. Department of Implant DentistryThe Second People's Hospital Xi'an China