1. Department of Oral and Maxillofacial Surgery, Gangnam Severance Hospital, Yonsei University College of Dentistry, Seoul, Korea
2. Department of Dentistry, College of Medicine, Hanyang University, Seoul, Korea
3. Department of Dentistry/Oral and Maxillofacial Surgery, College of Medicine, Hanyang University, Seoul, Korea
4. Department of Prosthodontics, School of Dentistry, Kyung Hee University, Seoul, Korea
5. Department of Oral and Maxillofacial Surgery, Korea University Anam Hospital, Seoul, Korea