[1] Zhengzhou Univ, Affiliated Hosp 1, Dept Gen Dent, 1 Jianshe Rd, Zhengzhou 450052, Henan, Peoples R China
[2] Zhengzhou Univ, Affiliated Hosp 1, Key Lab Clin Med, Zhengzhou 450052, Henan, Peoples R China
[3] Zhengzhou Univ, Affiliated Hosp 1, Dept Oral & Maxillofacial Surg, Zhengzhou 450052, Henan, Peoples R China