Schematic representation of the cervicomandibular branch of the facial nerve, its divisions and the surgical incision used to approach the platysma motor branch. (CFb) cervical branch of the facial nerve, which divides into the (Mb) mandibular branch and the (Cb) cervical branch. The Cb further divides into an (Ab) ascending branch, which is related to lower lip depression, and a (Db) descending branch, which innervates the lower portion of the platysma muscle. The Db is the branch used for transferring. (SM) submandibular gland.