Figure 1.

Deep-plane transition zone (DTZ). The borders of the trapezoidal-shaped DTZ are: laterally, an oblique line starting 4.5 cm anterior to the tragus and ending 2.5 cm antero-inferior to the ear lobule, even with the oral commissure; superiorly, the midpoint of the zygomatic arch; medially, the zygomaticus major muscle with an anterior bend over the prezygomatic space; and inferiorly, the transverse line even with the oral commissure. As shown in Figure 5, the deep-plane dissection continues inferior to this line, across the jawline and into the neck, but the area above it is the portion relevant to midface elevation.