J-H Jung1, D-W Lee2, S Lee1, J W Yi3. 1. Department of Oral and Maxillofacial surgery, Kyung Hee University Dental Hospital at Gangdong, Kyung Hee University, Seoul, Republic of Korea. 2. Department of Oral and Maxillofacial surgery, Kyung Hee University Dental Hospital at Gangdong, Kyung Hee University, Seoul, Republic of Korea. Electronic address: verycutebear@khu.ac.kr. 3. Department of Anesthesia and Pain Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, Republic of Korea.