A new approach to functional anatomy of the lower face: Role of the hyoplatysmal ligament, of the platysma and of the depressor labii lateralis.

BACKGROUND: Although there are numerous techniques for necklift, medium-term instability is frequent with this procedure. A misunderstanding of the functional anatomy of the neck may explain these unsatisfactory surgical outcomes.

OBJECTIVES: The author analyzes the functional anatomy of the platysma (PLA) and of the hyoplatysma ligament. The depressor labii lateralis (DLL) is described for the first time.

METHODS: The PLA was dissected in 4 fresh adult cadavers to infer its function and to reevaluate current knowledge regarding this anatomic region. In addition, 30 patients who presented to the author's private practice for rejuvenation of the lower face were photographed undergoing specific muscle contractions for functional analysis.

RESULTS: The PLA functions as a neck elevator only. Lower lip traction is controlled by independent antagonistic muscles, including the depressor labii inferioris, the anguli oris, and the DLL. The juxtaposition of these antagonistic muscles occurs at the mandibular line, which explains why the aging process is so distinct in this area. The hyoplatysmal ligament is responsible for the creation and stability of the acute cervicomandibular angle.

CONCLUSIONS: The aim of neck rejuvenation should be to restore elongation of the PLA posteriorly and to create posterior tension in the submental skin. Vertical platysmaplasty should be replaced with horizontal suturing of the PLA toward the hyoid and then to the skin to recreate the cervicomandibular angle and the submental area of the patient in youth.