1. Department of Prosthodontics, One-Stop Specialty Center, Seoul National University Dental Hospital, Seoul 03080, Republic of Korea
2. 618th Medical Company (Dental Area Support)/Dental Health Activity-Korea, Camp Humphreys, APO, AP 96297, USA
3. Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Republic of Korea