1. Department of Emergency General, The Affiliated Stomatological Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, P.R. China
2. Department of Oral and Maxillofacial Surgery, The Affiliated Stomatological Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, P.R. China
3. Department of Basic Stomatology, School of Savaid Stomatology, Hangzhou Medical College, Hangzhou, Zhejiang 310053, P.R. China