1. Department of Dental Implantology, The Catholic University of Korea Graduate School of Clinical Dental Science, Seoul, Korea.
2. Department of Periodontics, The Catholic University of Korea College of Medicine, Seoul, Korea.
3. Department of Oral and Maxillofacial Surgery, The Catholic University of Korea College of Medicine, Seoul, Korea.
4. Institute of Foreign Language Studies, Korea University, Seoul, Korea.
5. The Faculty of Liberal Arts, Eulji University, Seongnam, Korea.