Sang-Hoon Kang1, Moon-Key Kim, Won-Se Park, Sang-Hwy Lee. 1. Department of Oral and Maxillofacial Surgery, National Health Insurance Corporation Ilsan Hospital, 1232, Baekseok-dong, Ilsan-donggu, Goyang-si, Gyeonggi-do, 410-719, Republic of Korea. omfs1ksh@hanmail.net