The Art of the Needle: Understanding the Delicate Dance of Facial Muscles
When you look at a face, you see a story. But underneath the skin, there is a silent, intricate ballet of muscles, each pulling in a specific direction, each with a unique purpose. The challenge for any practitioner is not just to erase a line, but to understand the choreography behind it. A patient came to me, expressing concern about those little horizontal lines on her forehead. For her age, they were more pronounced than on her friends. The cause of those lines? The frontalis muscle. Its full name is the occipitofrontalis, because it runs all the way from the back of the head to the front. While it is technically one muscle, it usually moves independently due to adhesions. Our goal is to relax as much of this muscle as possible, but without losing the support for the eyebrow. This is especially critical in a female patient. If you cause a brow drop, she will be very unhappy. You can get away with it more often in men. Why? Because of a simple test: if you ask someone to apply eyeshadow, they instinctively lift their eyebrows to do it. Women are upset not just by the appearance of a droop, but by the loss of function—they can't move their eyebrows anymore. This insight taught me early on: it is not just about appearance, it is about the function of the muscle. We must leave some muscle moving as much as we can.
The Corrugator: The Frown Line's True Master
Right next to the frontalis, inferior to it, lies the next muscle of concern: the corrugator muscle. It starts deep on the bone and moves laterally, inserting into the surface of the skin, usually near the mid-pupil or slightly lateral to it. When someone does a big frown, you can see the insertion point—fibers directly connected to the skin. Anything lateral to that insertion point will not affect the frown line, but it does have a chance of affecting the frontalis muscle, especially if you go a little deeper. That will cause asymmetry to the brows. This is a very important point to know. We need to be very superficial and low dose here, not just to protect against eyelid ptosis (the levator palpebrae muscle is close), but because the frontalis causes more problems. If you go too lateral, you get brow asymmetry; if you do it on one side and not the other, you also get heaviness. So isolate the insertion point, and inject approximately five millimeters medial to it.
The Procerus and Depressor Supercilii: Subtle Pulls
Next, the procerus muscle pulls the brow down in the center. Not everyone has a strong one. You can see a downward pull, but it is often not powerful. You certainly do not need to put seven units into it—many do. Two units may give the same result. Then there is the depressor supercilii, which some consider a branch of the orbicularis oculi. It provides a slight downward and lateral pull when you frown. Whether it is a separate muscle or not is academic, because we treat it in the same place as the corrugator. The belly of the corrugator is in the same spot, so if we treat that sufficiently, we get those fibers as well.
The Orbicularis Oculi: A Tug of War
The orbicularis oculi muscle has an origin medially and connections with the lateral facial ligaments. These ligaments are attachments to the skin. When the muscle contracts, it contracts respecting where it is attached. When you relax one part of this muscle, the medial part will still pull toward its attachment, creating a strange pull in some people. This is a tug of war—a circular tug of war. Wherever you relax it, you will get a pull in the other direction. But this is not always bad. We actually use it for eyebrow lifts. When you close your eyes tightly, your eyebrows are pulled down. The muscle fibers here are pulling the eyebrow downward. If we relax them, the frontalis muscle becomes unopposed and can lift slightly more. The tug of war becomes in our favor if we relax here. But it is not enough to just relax here, because the levator palpebrae muscle runs all the way to the back of the globe, and its strongest portion is well within the globe behind the orbital septum. The orbital septum is a very tough structure—it is not easy for something to permeate through. That tells me most eyelid ptosis cases come from being too deep. You have either gone through the orbital septum, or there is some abnormality, or you went through the little foramen above. Depth is very important. If you respect that, you will enjoy many years without getting an eyelid ptosis.
Marking the Forehead: The Balancing Act
The forehead is the most difficult area to mark up. It is one of the areas where it is clearest that we are in a balancing act. We need some muscle to move and some to be relaxed. Most follow-ups are forehead follow-ups—too much movement or too little. You are either correcting for heaviness or trying to correct for too much movement into living lines. So I draw a box that is safe to treat. The principle: I want relaxed muscle and working muscle. Lower down, I want a bit of movement; higher up, I don't want much movement. I also want a trend toward more movement laterally, especially for a female. I would rather there was more movement here than there, but I don't want heaviness on the sides lifting the middle. To prevent brow heaviness, I leave about two centimeters (or about 50% of the forehead from the orbit) untreated. Where does the orbit start? You can feel for it—it is very close to the underside of the eyebrow. Two centimeters above that should leave enough muscle functioning. I follow the contour of the forehead; it is not a dead straight line. That gives me a safety zone. The area above that is a higher risk area, not a no-go area, but for a first-time patient, you would probably not treat there. Look for areas with no muscle movement—you can ignore them. There is an aponeurosis that may go down the middle of the forehead; some think it does, some think it doesn't. But broadly, the muscle has two bellies, and the middle is weakest. So I tend not to put an injection right in the middle.
The Eyebrow Lift: A Vector-Based Strategy
I want to elevate the eyebrows based on the arch. I want the muscle fibers that are directly pulling in that direction to be left untreated and as active as possible. So I draw a line following where the eyebrow arch should be—from the base of the nose through the eye and up here. That is the vector—the direction you want the muscle to pull. Once you have the direction, you need to figure out how much muscle to leave untreated. If you leave muscle untreated that is not part of this vector, you end up with a "ladder line"—lines running all the way up the side of the forehead. So I taper off. I try to leave as little muscle as possible to do the lifting while most of the lines fade. Over the years, I have learned to start with the base of the eyebrow measurement and choose the same distance apart, approximately where the meridian line is. Then I draw a line, mainly lateral to the medial line because lateral to this is no muscle. That becomes another boundary. If I want maximum eyebrow lift (which is not always needed), I treat the area carefully. On a big forehead, you can get ridiculous eyebrow lifts, but I might soften that. The concept is to fill the area with enough injections to reduce the strength of the muscle evenly throughout. I start right up against the boundary, remembering that each injection spreads about 1 to 1.5 centimeters—like a finger-sized injection. That is how I fill the space.
The Orbicularis Oculi: Superficial and Precise
Now, the orbicularis oculi muscle is very superficial under the skin—about 0.2 millimeters. We do not need to be deep. The deeper you go, the more side effects you get: lateral rectus issues, tear duct problems, and the one I forgot to mention earlier—the zygomatic muscle. I have never seen someone actually get that, but if you go deep straight through cheek fat, you hit the origin of the zygomaticus major, and they will get an asymmetrical smile. That is miserable. So I picture a sort of Ray-Ban shape muscle that splays around the whole eye. If you ask her to smile, you can often see the contraction of that bulge. That is where my most effective injections will go. I usually start at the tail of the eyebrow—a pretty safe place to start. It is more complex as you go inferior to the lateral canthus and near the cheek junction. Then I do a couple of minor doses, check everything, and ensure it looks broadly symmetrical. Just like in math, always look at the number and ask: does it actually make sense? Yes, it is a bit like that.