To comprehend the makings of a smile in its numerous manifestations we must first comprehend the underlying anatomy.

Below we list the three major muscles that add to a smile:

* The Zygomaticus Major - is the major "muscle of happiness". This stretched out muscle begins at the front area of the Zygomatic Arch (cheek bone) and attaches to the corner.

When the zygomaticus major contracts it bulges and raises the cheek while further deepening the Nasolabial Furrow or smile-line.

* The Malaris - rests on top of the zygomaticus major and is a long, ribbon-like deep-seated muscle. It begins at the temple and attaches to and forms the bottom part of the nasolabial furrow.

The malaris is the cheek muscle. It heaves up the cheek in an outwards and backwards direction making it bulge and giving it the puffy cheek look.

* The Buccinator - quadrilateral muscle forms the "cheek pad". It begins on the rear, inside of the jaw and attaches to the "corners" of the mouth.

When smiling the buccinator contracts thus heaving at the corners and widen the mouth.

As the mouth is widened and pulled by both the zygomaticus major and buccinator the lips are extended and flattened. So is the chin. The philtrum is reduced and the nostrils flare somewhat.

Below are still other minor muscles that add to the smile:

1. The Risorius - is a strange muscle because not everybody has one. Some people only have a risorius on one side of the face. Other people have a large, expansive triangular shaped one.

The Risorius begins in the tissue of the Masseter (whose action is made use of largely for chewing) and attaches to the corner of the mouth.

The risorius subtly draws the corner backwards and up. Its effect is generally observed in gentle smiles.

2. Incisivus Labii Superioris and Inferioris Superioris - The superioris does the lifting. These narrow, band-like muscles begin just above the incisor tooth area and also attach to the corner.

When fully shrunk, a puckering up of the lips (a kiss) is produced.

3. The Levator Labii Superioris is a narrow, quadrilateral muscle whose effect on the smile is somewhat restricted.

But, the higher part of this muscle adds to the volume of the cheek and the nasolabial furrow.

Over the three major muscles goes the most intricate of all the facial muscles, the Orbicularis Oris which functions throughout a large range of actions and expressions.

During a smile the bottom eyelids are also pushed upwards. This is a consequence of a secondary action where the Orbicularis Oculi (the muscle of the eye socket) contracts.

The nasolabial furrow is deepened as it is simultaneously pulled and pushed upwards and outwards. It is best to play down the sharp fold of the nasolabial furrow otherwise the smile will degenerate into a scowl.

As the corner of the mouth is pulled out and upwards the skin is gathered into subtle vertical ridges.

The interstice of the mouth curves upwards, broadening and flattening the lips while reducing the philtrum. The nostrils of the nose also widen as they are pulled outwards.

The higher portion of the nasolabial furrow is produced by a slender, three-part muscle called the Levator Labii Superioris Alaeque Nasi. This is the muscle that produces wrinkles in the nose during sniffing.

The parts of this muscle are the furrow part which attaches to the top part of the nasolabial furrow; the alar part which attaches under and behind the wing of the nose (Alae Nasi); and the lip part which attaches continuously into the ridge just above the top lip and to the philtrum.

When rendering the nasolabial furrow be careful not to over-do it. A subtle suggestion is all that is needed. Otherwise your lovely smile will quickly degenerate into a sneer.

With this we have detailed and discussed the most significant muscles that are involved in the smile. This should put you on the correct path for grasp
ing the anatomy of the smile.