1. Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Shangdong University and Shandong Provincial Key Laboratory of Oral Tissue Regeneration and Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, Shandong 250012, P.R. China
2. Department of Stomatology, Qingdao Municipal Hospital, Qingdao, Shandong 266071, P.R. China
3. Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, P.R. China