1. Department of Psychology; Princeton University; Princeton NJ USA
2. Department of Advanced Periodontology; School of Dentistry; University of Southern California; Los Angeles CA USA
3. Department of Oral and Maxillofacial Surgery; College of Dentistry; Seoul National University; Seoul Korea
4. Department of Oral and Maxillofacial Surgery; Asan Medical Center; College of Medicine; University of Ulsan; Seoul Korea