Answer:
Gillies and Millard described a procedure for oral commissure reconstruction using a superiorly based rotation advancement flap of available vermilion for the upper lip and cutaneous excision with mucosal advancement for the lower lip. In 1980, Su et al. proposed a “reversed” Gillies and Millard technique using an inferiorly based flap. After excision of the cutaneous scar, a vermilion flap from the upper lip is formed and rotated downward to reconstruct the lower lip. Buccal mucosa is then advanced and used to reconstruct the upper lip. This allows for the upper lip to be slightly inverted and less prominent with the lower lip slightly everted and more prominent which is the case in the normal oral commissure.