목적: The aim of the present study is to provide the course of the marginal mandibular branch (Mbr), especially within the platysma muscle, and to elucidate the relationship between the number of the Mbr and its course. 방법:Twenty-nine specimens from 12 embalmed and 4 fresh cadavers (10 males, 6 females mean age, 73.7 years) were examined in this study. 결과:The Mbr had a proceeding area inferior to the inferior border of mandible (IBM) in 16 cases (55.2%). The branch of Mbr was observed within 5mm from the gonion in 24 cases (82.8%) and located within 10mm from the intersection point (FM) of the IBM in 26 cases (89.7%). The number of Mbr in average is 1.50.6 and the cases with multiple Mbr twigs were deemed to have a branch passing under the IBM. In 13 cases (44.8%), one more branch proceeded under the IBM and ran superiorly, passing over the IBM. In these cases, the reaching point of Mbr on the IBM was located 33.15.2mm anterior to the gonion and 6.75.7mm anterior to the FM. A twig innervating the platysma was ramified from the Mbr in two cases (6.9%). 결론:The gonion and FM can be a reliable landmark for identifying the Mbr. However the area beneath the gonion cannot be a safe area to prevent the Mbr damage. Risdons technique seems to be reliable, but the surgeon should be informed that a patient with multiple Mbr twigs is more likely to have a branch passing under mandible.