1. Department of Oral Medicine, Stomatological Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China
2. Department of Oral Surgery, Stomatological Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China
3. Department of Oral Pathology, Stomatological Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China