1. Department of Prosthodontics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
2. Department of Oral and Maxillofacial Surgery, Henan Provincial Stomatological Hospital, Zhengzhou, Henan, China
3. Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China