The importance of a smile in human interaction can not be denied. It is a seemingly simple facial expression that actually involves a large number of facial muscles that must work with great precision to create what one recognizes as a genuine smile. There are 43 muscles in the face and the number that help make a smile has been debated to be between 17 and 26 of them. But not all smiles look and feel the same.
Scientific research has actually been done to discern the differences between a genuine and a fake smile. Analyzing photographs of people smiling at an actual positive event and then contrasting that with the same people faking a smile, the subtle difference between the two is a function of the number of muscles activated. In a genuine smile the elevator muscles of the upper lip (zygomaticus major) as well as those around the eye (orbicularis oculi) are activated. This creates an upper lip that moves upward, eyebrows that are pulled down and cheeks that are lifted up. This creates crow’s feet wrinkles at the corner of the eyes as the lips move in smiling. In a fake smile, the lip is lifted in a grin but the orbicularis muscle is not activated and there is little to no change around the eyes. The change in and around the corner of the eyes is what changes the real from the faked smile.
What is the relevance of understanding the mechanisms of smiling? Botox and the art of aesthetic facial expression management is the reason. Botox is powerfully effective for reducing glabellar furrows, horizontal forehead creases and crow’s feet. But when it is ‘overdone’, one can appear unnatural. Understanding the mechanism of the smile explains why this happens.
When enough of the orbicularis muscle is deactivated, crow’s feet wrinkles are either significantly reduced or eliminated entirely. Thus when one smiles, even in a completely genuine smile evoked from real emotion, it may appear fake in the person who has been treated by Botox. Many patients express concern that if their forehead has too much Botox it will make them look unnatural. But the science of facial expression indicates that the area around the corner of the eye is the real culprit.
To get the optimal benefits from Botox, the concept of less is more may really apply. A more conservative approach to Botox dosing with the goal of reduction rather than elimination of muscle movement leads to more natural results. This is why I prefer no more than 16 total units for both sides in the crow’s feet area…so patients can maintain a natural and genuine smile.
Dr. Barry Eppley
Indianapolis, Indiana