KEY ELEMENTS OF THE BROAD SMILE
KEY ELEMENTS OF THE BROAD SMILE
G. Chin seems larger because of moving up of lips. Under-the-lip crease disappears.
The first stage of a smile is the most elusive. We notice when the zygomatic major so much as twitches; in the drawing of a weak contraction (top left) it's contracting a bit more than the minimum. The corner of the mouth is the first thing to change, rising above its neutral point (A). The corner does not move by much before the cheeks swell and dimples appear; it doesn't change by much before the whole LBL begins to stretch. The broad smile of a strong contraction (below) is not so subtle. Changes start at the bottom of the cheeks (B); on some faces the deepening of the nasolabial fold would not be as deep in the early stage of a smile. Even in a slight smile (C), shallow wrinkles across the lower lip are smoothed. The cord along the side of a smile stretches down to the chin like a rope caught under the face. It often catches the light (D). The pull of the zygomatic is stronger on this side (E). Note how far past the rest of the lips the corner of the mouth has moved.
A. The line between the lips has a taut look like a V with a very open angle.
B. The nasolabial fold intensifies and is pulled to the side. Just before it ends, it hooks downward, bracketing the mouth corner.
C. The cheek balls up. Steepest edges (watch for sharp shadow breaks) are here. The soft edge is next to the nose. The highlight is crisp on the upside of the cheek, showing the stretching of skin (1).
D. Angled cords hang from bottom of cheek mound. Deep inner edge may connect with nasolabial fold; dimple lies on the outside edge.
E. Upper lip becomes a simple, curved plane. Filtrum disappears.
F. Lips are thinned and smooth-looking. Sharp highlight on stretched lower lip. The mouth is now wider; the relaxed mouth is directly below middle of eye; smiling mouth is directly below outer edge of iris.
Downward Puller I: Triangularis_
The triangularis, when contracted, creates a mouth that is an inverted smile. Everyone knows that if you take the curve of the mouth in the "have a nice day" face and turn it upside down, you get a frown, and the triangularis is one of the muscles responsible for creating that change. Charles Darwin called it the "muscle of grief," but that's giving it too much credit; it's really the triangularis plus the mentalis that creates the pout, and the mentalis often does it on its own.
The triangularis, unlike the mouth muscles described so far, seems to act only on the closed mouth. And when it does contract, it's almost always in the company of the mentalis.
The triangularis (also called the mouth angle depressor) has its fixed end embedded in the bone of the chin, somewhat to the side of the center. From there, it rises diagonally to the corner of the mouth, where it attaches in virtually the same place as the zygomatic major, just beyond the end of the LBL. When it contracts, it draws the mouth corner and the LBL sharply downward, often extending the LBL past the lips.
The triangularis was one of the muscles I had in mind when I mentioned the fact that some people look like they're scowling even when they're not. In older faces, the creases that extend the mouth corner can look a lot like the way the mouth looks when triangularis stretches it. The differences are very subtle and turn on distinguishing between a crease (old person) and a gap (stretched LBL). From life, it's relatively easy; from photos, it can take work. Look also for the bulges that show that the muscle is pulling, not present in the relaxed older face.
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