1. 1Department of Periodontics & Oral Medicine, University of Michigan, School of Dentistry, Ann Arbor, Michigan.
2. 2University of Michigan Rogel Cancer Center, Ann Arbor, Michigan.
3. 3Department of Oral and Maxillofacial Surgical Oncology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
4. 4Department of Oral Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.