1. Department of Oral and Maxillofacial Surgery, Division of Oral Oncology, Showa University, School of Dentistry, 2-1-1 Kitasenzoku, Ohta-Ku, Tokyo 145-8515, Japan
2. Showa University Head and Neck Oncology Center, 1-5-8 Hatanodai, Shinagawa-Ku, Tokyo 142-8555, Japan