1. Department of Oral & Maxillofacial Surgery; School of Dentistry; Seoul National University; Seoul Korea
2. Department of Oral and Maxillofacial Surgery; Dongtan Sacred Heart Hospital; Hallym University Medical Center; Kyonggi-do Korea
3. Department of Occupation and Environment; Konkuk Postgraduate Medical School; Choong-Ju Korea
4. Oral Cancer Center & Clinical Trial Center; Seoul National University Dental Hospital; Seoul Korea
5. Dental Research Institute; Seoul National University; Seoul Korea