1. Department of Oral and Maxillofacial Surgery, Dankook University Jukjeon Dental Hospital, Yongin, Korea.
2. Department of Oral and Maxillofacial Surgery, Gachon University Gil Medical Center, Incheon, Korea.
3. Department of Oral and Maxillofacial Surgery, Section of Dentistry, SMG-SNU Boramae Medical Center, Seoul, Korea.
4. Section of Dentistry, SMG-SNU Boramae Medical Center, Seoul, Korea.