[Guo, Jian] Cent South Univ, Xiangya Stomatol Hosp, Changsha 410008, Hunan, Peoples R China.
[Yang, Fei] Univ South China, Sch Publ Hlth, Hunan Prov Key Lab Typ Environm Pollut & Hlth Haz, Hengyang 421001, Peoples R China.
[Guo, Jian] Cent South Univ, Xiangya Sch Stomatol, Changsha 410008, Hunan, Peoples R China.
[Wei, Jia; Massey, Isaac Yaw; Yang, Fei; Huang, Feiyu; Luo, Jiayou] Cent South Univ, Xiangya Sch Publ Hlth, Hunan Prov Key Lab Clin Epidemiol, Changsha 410078, Peoples R China.