Macrostomia is a rare facial malformation caused by failure of mesodermal migration merging to obliterate the embryonic grooves between the maxillary and mandibular processes during the early phase of gestation. This kind of malformation may require the use of several surgical techniques to repair the facial structure. Bibliographic studies concerning the repair of this malformation are focused on the description of mucosa, muscle, and skin flaps disconnected between them. This article presents a description of a unique myomucosal flap from vermillion for the correction of the existing malformation in the oral commissure.