Facial Proportions, Bones, Muscles

Art 173 A The Illusion of Life: Facial Animation – Steve DiPaola




The Skull - fig

            The skull is the foundation of the head and understanding the skull and it’s bones and proportions help to understand the human head.

The Skull fits proportionately into head - fig

Some proportions of the skull:

- The 50/50 vertical point of the skull is right through the center of the eye wells – fig

- The skull is square in the it is as tall as it is deep – fig - so from the side view a human skull fits perfectly in a square. Its height is the same value as its depth.

- The skull is said to be broken up into 2 masses, the cranial and the facial, which are 2/3, 1/3 respectively. – fig - The cranial which is indicated by "A" in the figure, occupies 2/3's of the total skull mass but is the least detailed part of the head. The facial mass, indicated by "B" in the figure is the most details portion of the skull, yet it occupies only 1/3 of the head mass.



Skull Bones –

We will now discuss the bones of the skull as indicated with their letter values in the following : fig
Here is an interactive chart of the bones of the skull (note: they differ slightly from the notes below): chart


A-    Frontal bone – forehead structure terminates at the brow.

B-    Temporal Ridge – runs along the outer side of the upper skull – creates the square shaped of the upper head.

C-    Parietal bone – the side of the head – a smooth curved surface.

D-    Nasion – the point where the front of the head meets the nasal bone.

E-     Supraorbital margin – the ridge above the eyes.

F-     Nasal bone – the small bone at the top of the nose.

G-    Orbital cavity – the eye hole.

H-    Infraorbital margin – the lower eye ridge and upper portion of the cheek.

I-       Zygomatic bone – the cheekbone that lies under Infraorbital margin.

J-      Maxilla – the upper jawbone under the nose.

K-   Mandible - lower jaw bone.

a.       Note that the rotation point of the jaw is just behind the earlobe at point "A" in the figure. - fig

b.      Note the Mandible can move side to side ( horizontally).

L-     Mental protuberance – very tip of the jaw bone – the chin.


Male and Female Skull Differences - Note: Male/female differences not on midterm

Skull difference between Male and Female as indicated by their letter value on the figure- fig

            A- The male cranial mass is more blocky and massive compared to the females which more rounder and tapers at the top.

            B- The females Supraorbital margin is sharper while the males is rather round and dull.

            C- The Zygomatic bone is more pronounced on the male skull.

            D- The Mandible of a female is more rounded while the male's is squared.

            E- Males have a deeper cranial mass

            F- The supercilary arch is large and pronounced in the male.



Eyes Issues

            The eye opening is not a symmetrical oval, but rather oblique. The high point of the upper eyelid is close to the inside of the eye while the low point of the lower eyelid is close to the outside of the eye. See the figure - fig

Common mistakes –
           - Upper eye creases are often overlooked: incorrect: fig  - correct: fig
           - Floating eyelid where a shadow is cast (eye not sealed against eyelid) is a common mistake: fig

           - The Iris needs to hover just above the upper eyelid allowing a sliver of white to be visible near the lower eye shape - fig


Facial Muscles

We will now discuss the muscles of the face as indicated with their letter values in the following : fig
Here is an interactive chart of the muscles of the face (note: they differ slightly from the notes below): chart


A – Masseter – the clenching muscle. 

-         used to clench teeth and with lower jaw – fear, yawn.

B – Levator labii superioris – the sneering muscle.

                        - raises the upper lip beneath the nostrils – disgust, disdain.

            C – Zygomnaticus major – the smiling muscle.

- raises the mouth upward and outward – smiling, laughing.

D – Triangularis – the facial shrug muscle.

-         pulls the corner of the mouth downward – sadness, crying, miserable.

E – Depressor labii inferioris – the lower lip curl muscle.

-         pulls the lower lip down and out – around the lips – surprise.

F – Mentalis – the pouting muscle.

-         raises and tightens the chin -  sadness, fear.

G – Orbicularis oris – the lip tightener muscle.

            - compress and purses the lips – circles the mouth – disdain, repulsion.
H – Corrugator – the frown muscle.

-         compresses the skin between the eyebrows – frown, concern, concentration.

I – Orbicularis oculi – the squinting muscle.

-         closes the eyelids, compresses the eye opening, encircles the eye – close, wink, tired.


J – Frontalis – the brow lifting muscle.

-         draws the scalp down, wrinkles, two sides – fear, smile.

K – Risorius/platysma – the lower lip stretching muscle.

            - draw the lower lip down and outward – neck muscle – crying, terrified.