[1] Northwest Univ, Coll Life Sci & Med, Xian, Peoples R China
[2] Fourth Mil Med Univ, Sch Stomatol, State Key Lab Mil Stomatol, Xian 710032, Peoples R China
[3] Fourth Mil Med Univ, Natl Clin Res Ctr Oral Dis, Sch Stomatol, Dept Gen Dent & Emergency, Xian 710032, Peoples R China
[4] Northwest Univ, Xian Peoples Hosp, Xian Hosp 4, Dept Anesthesiol & Perioperat Med, Xian, Peoples R China