Before jumping into getting botulinum toxin for the face, we really need to understand what we’re messing with. I believe that the facial muscles and their connection to the brain, are the most highly evolved of all human bodily functions. Firstly, what are the functions of the face?Most practitioners of botulinum toxin approach the face as two halves. The upper half that is more forgiving, and the lower half that requires more caution. Mobility of the lower face is essential to clear speech and enunciation. The muscles around the mouth and cheeks keep a tight seal at the lips to prevent drooling and are major components in the process of eating and drinking.
What is under appreciated however is that there are similarly important autonomic functions for the upper half of the face as well. The eyelids move to protect our precious eyes from the environment, and automatically adjust their positions in response to what the eyes sense. In dry and windy conditions, the orbicularis muscles tighten the aperture to minimize mucus membrane exposure. Sudden bursts of light similarly cause an immediate reflexive closing of the eyes to shield the retina from photo-toxicity. Although complications from botulinum toxin injections in the upper face are relatively mild and rare, they nearly always involve eyes.
I believe however that the most sophisticated function of our faces is in communication. The face is the single most visible portion of our bodies, especially for this Seattle’s winter. As an ophthalmologist, I am acutely aware that our eyes are our windows to the world. But as an oculoplastic surgeon, I have learned to appreciate how the muscles and skin around the eyes serve as the window into our souls. They are the focus of gaze during conversations with other people and even animals. We have evolved to “read” eyes and are surprisingly good at it. Everyone knows that the difference between a true smile and a fake one is in the eyes.
Botulim toxin injections were first approved by the FDA for human use by an ophthalmologist who injected the substance into the muscles on the eyes to straighten strabismus. It was first approved for cosmetic purposes in the muscles around the eyes at the glabellar folds. Since then use of the chemical has spread to all areas of the face. In Shanghai, we even injected it into the masseter muscles of the jaw for aesthetically pronounced jowls. The technique however to apply it to the facial muscles truly requires some appreciation for not just the anatomy, but also for how they work in dynamic facial expression. Although commonly used to reduce the visibility of dynamic wrinkles, there is growing use of botulinum toxin to aesthetically alter the balance of facial expressions. By minimizing the contractions of typically negative expressing muscles, the face at rest develops a more positive and confident pose. The downside however is that when the “negative” expressions are attempted, the balance can be some what abnormal appearing. Unfortunately there is give and take in everything, even for botulinum toxin.
I have helped to write a review article with my Cleveland Clinic colleague and mentor regarding the medical and aesthetic uses for botulinum toxin injections around the eyes and face. Further details to come upon publication.