When the zygomatic major contracts, the oval of the relaxed mouth is stretched into a more angular shape. The smile is the result of the pull of the muscle working against the resistance of the teeth. The teeth keep the smile flat in the middle (A); (B) lines mark where lips are pulled free of teeth and turn to point back toward the ears, in the direction of the pull. The upper lip is always straighter— the pull is nearly at its height. The lower lip has farther to go, so it angles more. Note difference in the outer legs (C).
FORMS OF THE UPPER LIP
The upper lip in the smile is basically a simple shape— flat and curved like a piece of tape, tapering at each end. The center part still has its Cupid's bow, stretched wide but not entirely lost. The outer legs move off the teeth and change direction, curving around to the side. Look for subtle break in outline, change in tone.
The lower lip is much less uniform. The thick, rounded center section contrasts with the thin, angled outer legs. The center part looks thicker because the top surface is exposed. The center can be thought of as two egg forms, side by side, attached to thin handles. The outer legs break sharply with the center directly below a similar break in the upper lip. The upper edge is sharp and often catches bright lights, contrasting with the deep shadow above it.
Three types of upper lip line in the smile: (D) and (E) are nearly straight (D curves slightly upward and E slightly downward); (F) is strongly bowed upward—all have a flat middle section; the variation is in the curve of the outer legs. Remember that perspective will change the apparent direction of these curves.
Was this article helpful?