Figure 1.

References used to superimpose T1 (yellow) and T2 (green): Forehead area (1, glabella, the most prominent midline point between the eyebrows), nasion area (2, soft tissue nasion, the corresponding soft tissue point of the frontonasal suture), exocanthion (3/4, The point at the outer commissure of the eye fissure), and endocanthion (5/6, the point at the inner commissure of the eye fissure).