1 Department of Stomatology, Jiaozhou Central Hospital of Qingdao, Qingdao, Shandong, China.
2 Department of Stomatology, The Second Affiliated Hospital of Shandong First Medical University, Tai'an, Shandong, China. Electronic address: mymanshu@126.com.
3 Department of Stomatology, Qingdao Women and Children's Hospital, Qingdao University, Qingdao, China. Electronic address: xingbin200917@126.com.