1. Private practice; Vallejo CA USA
2. Department of Advanced Periodontics; University of Southern California; Los Angeles CA USA
3. Private practice; Beverly Hills CA USA
4. Department of Prosthodontics; College of Medicine; Asan Medical Center; University of Ulsan; Seoul Korea
5. Department of Oral and Maxillofacial Surgery; College of Medicine; Asan Medical Center; University of Ulsan; Seoul Korea