1. Department of Stomatology, Mudanjiang Medical University, Affiliated Hongqi Hospital, Mudanjiang, Heilongjiang 157000, P.R. China
2. Second Department of Orthopedics Surgery, Mudanjiang Medical University, Affiliated Hongqi Hospital, Mudanjiang, Heilongjiang 157000, P.R. China
3. Department of Stomatology, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157000, P.R. China