Anatomy of the Mouth

The plastic anatomy of the mouth is an important topic for artists because the shape and position of the mouth greatly affect the face as a whole.

If we look at a closed mouth, we see the closed lips and the surrounding skin. The mouth area borders the cheeks, nose, and chin.

The outer part of the mouth is formed by the orbicularis oris muscle, which has two parts – the labial part and the marginal part. The labial part forms the lips, while the marginal part is a flat subcutaneous muscle plate.

A basic knowledge of the anatomy of this part of the face is extremely useful if you, as an artist, want to draw realistic lips and construct complete, convincing portraits.

There are many different lip shapes – from rounded and full to thin and elongated. Cartoonists often depict simple and ingenuous characters with large lips and more calculating characters with thin ones. Of course, this has nothing to do with reality, since a person’s character cannot be determined by facial features.

The shape of the lips can also be affected by large, full cheeks. In stylized drawings of pirates or drawings of ancient warriors, we often see scars crossing the lips. This artistic technique can give a character a tougher appearance.

Oral cavity

When talking, breathing, or deliberately opening the mouth, we can see the oral cavity. The oral cavity is divided into two spaces – the oral cavity proper and the vestibule.

The vestibule of the mouth is a narrow space bounded by the cheeks, teeth, and gums. The oral cavity proper is bounded in front by the teeth and gums, above by the hard palate, and below by soft tissues, including the tongue and floor of the mouth.

Tongue

The tongue is a movable organ composed of several muscles. Some muscles lie within the tongue itself, while others connect it to surrounding bones and tissues.

The muscles within the tongue change its shape – for example, making it narrower, flatter, or more curved. The muscles that attach the tongue to surrounding areas allow it to move within the mouth or protrude outward.

When a cartoonist wants to portray a character as very tired, they may draw the character with their tongue sticking out.

The tongue is essential for speech. It is also involved in chewing, moving food within the mouth, and swallowing.

Teeth

We can see a person’s teeth when they smile broadly or open their mouth. An exaggeratedly wide smile is also often used for sinister characters – for example, in drawings of the Joker or drawings of the Green Goblin.

An adult typically has 32 permanent teeth, which are set in the alveolar sockets of the upper and lower jaws. Human teeth are grouped into four categories – incisors, canines, premolars, and molars. The teeth in each category differ in both appearance and function.