1. Department of Respiration, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
2. Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
3. Prosthodontics Department of the Stomatological Hospital, Jilin University, Changchun, Jilin 130021, P.R. China