Affiliation: | a Department of Oral and Maxillofacial Surgery, College of Medicine and Medical Research Institute, Chungbuk National University, #62 Gaeshin-Dong, Heungdeok-Gu. Cheongju, Chungbuk, 361-240, South Korea b Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University #28 Yeongeon-Dong, Jongro-Gu, Seoul, 110-460, South Korea |