1. Department of Oral Medicine, School and Hospital of Stomatology, Hebei Medical University, Shijiazhuang, People's Republic of China
2. Department of Oral Pathology, School and Hospital of Stomatology, Hebei Medical University, Shijiazhuang, People's Republic of China
3. Department of Oral Maxillofacial Surgery; Hebei Key Laboratory of Stomatology, Hebei Clinical Research Center for Oral Diseases, School and Hospital of Stomatology, Hebei Medical University, Shijiazhuang 050017, People’s Republic of China