1. Department of Cardiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, No. 6 Shuangyong Rd, Nanning 530021, Guangxi, P.R. China
2. Department of Orthodontic, the Affiliated Dental Hospital of Guangxi Medical University, Nanning, No. 10 Shuangyong Rd, Nanning 530021, Guangxi, P.R. China