1. Department of Prosthodontics and Research Institute of Oral Science; Gangneung-Wonju National University; Gangneung South Korea
2. Department of Dentistry, Uijeongbu St. Mary's Hospital; Catholic University of Korea; Uijeongbu South Korea
3. Department of Oral and Maxillofacial Surgery, Uijeongbu St. Mary's Hospital, College of Medicine; The Catholic University of Korea