1. Department of Oral and Maxillofacial Surgery, Nara Medical University, Nara, Japan;
2. Gunma University Heavy Ion Medical Center, Gunma, Japan;
3. Department of Future Basic Medicine, Nara Medical University, Nara, Japan;
4. Department of Otolaryngology – Head and Neck Surgery, Nara Medical University, Nara, Japan;
5. Department of Radiation Oncology, Nara Medical University, Nara, Japan