Cervical Branch of Facial Nerve: An Explanation for Recurrent Platysma Bands Following Necklift and Platysmaplasty.

Background: Recurrent platysma bands remain a common problem in neck rejuvenation.

Objectives: The goals of this cadaver study were to document the course of the cervical branches of the facial nerve and investigate the pattern of platysma muscle innervation before and after various platysmaplasty maneuvers.

Methods: A total of 8 fresh cadaver specimens were dissected for a total of 16 hemifaces/necks. After subcutaneous undermining and identification of the main trunk of the facial nerve, the cervical branch was dissected as distally/anteriorly as possible under loupe magnification. The following 4 platysmaplasty maneuvers were each performed on 4 hemifaces/necks: platysma window, extended SMAS with platysma flap, full width platysma transection, and lateral skin-platysma displacement (LSD). Upon completion of the techniques, the integrity of the cervical branches was evaluated.

Results: Contrary to some reports, all specimens in this study had only 1 main cervical branch. There were no branches detectable under 3.2× magnification until branches were given off to the platysma muscle at approximately the location of the facial vessels. The main cervical branch continued distally/anteriorly to the medial edge of the muscle below the thyroid cartilage. After performing the various platysma techniques, all cervical branches were in continuity in all specimens. Specifically, the main cervical branch was in continuity to the medial border of the muscle caudal to all platysmaplasty maneuvers.

Conclusions: Undermining the platysma muscle results in no injury to platysmal innervation unless continued beyond the facial vessels. Recurrent bands are likely related to persistent innervation of the medial platysma, which remains intact cranial and caudal to any described platysmal transection maneuvers.