作者单位:Shanxi Med Univ, Sch & Hosp Stomatol, 63 Xin Jian Nan Rd, Taiyuan 030001, Shanxi, Peoples R China[1]Sichuan Univ, West China Hosp Stomatol, Natl Clin Res Ctr Oral Dis, State Key Lab Oral Dis, 14,Sect 3,Ren Min Nan Rd, Chengdu 610041, Sichuan, Peoples R China[2]