1. Department of Plastic Surgery, The First Affiliated Hospital of Anhui Medical University, Anhui Medical University, Hefei 230032, China
2. Key Lab. of Oral Diseases Research of Anhui Province, College & Hospital of Stomatology, Anhui Medical University, Hefei 230032, China
3. School of Dentistry, University of Detroit Mercy, Detroit, Michigan 48208-2576, United States
4. Key Lab. of Advanced Technology for Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China