1. Department of Radiotherapy, The Affiliated Hospital of Qingdao University, Qingdao 266000, China
2. School of Public Health, Qingdao University, Qingdao 266071, China
3. Department of Molecular Craniofacial Embryology and Oral Histology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo 113-8510, Japan
4. Department of Oral, Plastic and Aesthetic Surgery, Hospital of Stomatology, Jilin University, Changchun, Jilin 130021, China
5. Department of Radiotherapy, Yizhou Tumor Hospital, Zhuozhou 072750, China
6. Department of Radiotherapy, University of Tsukuba Hospital, Tsukuba 305-8576, Japan
7. Department of Pharmacy, Qingdao University of Science and Technology, Qingdao 266041, China