1. Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Chiba 261-8502, Japan
2. Department of Biomarkers for Early Detection of Cancer, National Cancer Center Research Institute, Tokyo 104-0045, Japan
3. Department of Oral Medicine, Oral and Maxillofacial Surgery, Tokyo Dental College, Chiba 272-8513, Japan
4. Oral Cancer Center, Tokyo Dental College, Chiba 272-8513, Japan