Figure 5.

Areas of undermining for the author's technique. Limits of skin (in blue) and SMAS (in red) undermining for the author's technique, with the DTZ entirely within the red area of composite-flap undermining. The area of undermining medial to the zygomaticus major muscle is subcutaneous by definition, since there is no SMAS layer in this zone. (The premasseteric dissection joins an extended subplatysmal dissection into the neck. Platysma, but not skin, is undermined towards the midline of the neck, preserving cervical facial nerve branches. This continuation of the facial composite flap into the neck generates a very smooth, youthful jaw and neckline, while elevating ptotic submandibular glands and avoiding irregularities characteristic of subcutaneous neck dissection.)