There is a specific way that a small neurotoxin complication becomes a three-month problem, and it is not the original injection. It is the correction. Choosing a botox asymmetry correction dose the same way you would choose a treatment dose — reaching for your standard units for that muscle — is how an injector converts a four-week asymmetry into a twelve-week asymmetry pointing the other way. Dr. Chris Croley calls the result what it is: chasing.
"If we start with one side elevated or hyperactive, and now we go and fully treat those muscles that are hyperactive with a full dose, that's going to last a longer duration than the side that we inadvertently treated with a lower dose. So we're constantly having to chase that hyperactive muscle or the overactive muscle creating the asymmetry."
That sentence contains the entire failure mode. It is worth taking apart slowly, because the logic that produces the loop is completely reasonable at every individual step. That is what makes it dangerous.
How the loop starts
Follow a real sequence.
A patient is treated. Some dose diffuses into a muscle you did not intend to treat — say a depressor on the right side. That muscle receives a fraction of a dose. Three weeks later she presents with the right side of her mouth sitting flat and the left side moving normally, which now reads as overactive by comparison.
You examine her. The left side is the problem, visually. So you treat the left side — the moving side — with what you would normally put in that muscle. Call it your standard dose.
Now look at what you have created. The right side is carrying a fractional dose that will wear off comparatively quickly. The left side is carrying a full dose that will run its complete course. Within a few weeks the right side recovers, the left side does not, and the patient is asymmetric again — in the opposite direction, and for longer than the original problem would have lasted.
She returns. The right side now looks overactive. You treat the right side. And you are in the loop.
Every cycle of that loop adds toxin to a face that did not need more toxin, adds cost and appointments, and extends the total period of asymmetry well beyond what watchful waiting would have produced. Dr. Croley's framing of the underlying case is the corrective: "the patient didn't necessarily need more toxin. In this case she needed better balance."
Why the loop compounds rather than converging
The intuition that each correction should get you closer to symmetry is wrong, and the reason is that you are managing two clocks, not one.
The original complication is on a short clock, because it came from a partial dose. Your correction is on a long clock, because it came from a full dose. Dose equals duration — the more units reach a muscle, the longer it stays weak. Correcting a short-clock problem with a long-clock intervention guarantees that the two effects will fall out of phase.
Worse, the phase mismatch grows with each cycle. Every full-dose correction outlives the problem it was correcting, which creates a new problem that you then correct with another full dose. The system does not damp. It oscillates, and the oscillations get longer.
There is only one way to make the two clocks converge: make the corrective dose small enough that it decays on a timescale comparable to the problem it is addressing.
The rule Dr. Croley teaches
His instruction for correction is explicit and it is different from his instruction for treatment:
"When we're managing complications, it's important to understand that we usually start with lower doses than we would typically treat those muscles with. Otherwise we're going to end up with the other type of asymmetry."
Start lower than your usual dose for that muscle. Not your usual dose. Not a cautious version of your usual dose. Lower than it, deliberately, because the goal of the injection is different.
This is the point that clinicians resist, because it feels like under-treating. The instinct is that if a muscle is visibly too strong, it needs a proper dose to bring it down. But you are not trying to weaken that muscle to its normal treated state. You are trying to bring it into line with a partner muscle that is temporarily weak and is going to recover. Aiming at the current state of the weak side means overshooting the state it is heading toward.
Dr. Croley's standing rule covers the rest: "I want you to always be conservative. You can always add more. It's hard to take this away."
That asymmetry — additions are cheap, subtractions are impossible — is the governing economics of every neurotoxin decision, and it is at its sharpest during correction, where the whole problem was caused by having too much toxin somewhere.
How much lower?
He does not give a number, and neither will this article. Here is the honest reason: the correct corrective dose depends on the muscle, its size, its strength in that individual, how much of the original diffusion dose landed on the opposite side, and how far along that effect has already decayed. Nobody can measure the second of those. "We don't have magic glasses," as Dr. Croley puts it — there is no way to know exactly how much toxin reached the unintended muscle.
What he does give is the reasoning sequence, and it is the transferable part:
1. Assess muscle strength, not just the visual asymmetry. "First thing we're going to do is look at the muscle strength. And so as we start to assess what's causing the asymmetry, we need to assess the muscle, we need to assess the muscle strength." A visually dramatic asymmetry in a weak muscle needs less toxin than a subtle one in a strong muscle.
2. Assess the muscle itself, not only its movement. "We're going to look at the anatomy of the area that's moving and not just the movement but the size of the muscle. If this is a young guy with a really thick, dense muscle, we're probably going to have to use a higher number of units or a higher dose." Bulk and density scale the dose; they do not change the instruction to start below your usual figure.
3. Establish what your usual dose for that muscle would be. You need the reference point before you can deliberately go under it. For off-label muscles this means extrapolating from muscles of similar size and activity — a reasoning method in its own right.
4. Go below it, and plan to reassess rather than to finish. The corrective injection is a first move, not a final answer.
5. Distribute rather than concentrate where the anatomy allows. In the published case Dr. Croley reviews, the mentalis was treated fractionated across the muscle rather than as a single deposit, to address a chin imbalance without creating a new focal weakness.
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The number is not the lesson
The case Dr. Croley teaches from involves fourteen units in total. He goes out of his way to say that the number is not the content:
"The lesson is not we're given this or treating this patient... it's not that we're treating with 14 units. It's how we place the 14 units. Why we chose 14 units, what muscles did we treat."
This is the correct way to consume any published correction case, including this one. The unit count reflects one patient's muscle mass, one pattern of prior dosing, one degree of asymmetry, and one set of goals. What transfers is the logic that produced it: identify the muscles actually responsible, prioritise them, dose below your usual figure, distribute appropriately, and reassess.
Copying the number without the reasoning is how a case report becomes a complication.
Prioritise, do not treat everything
A correction plan that addresses every asymmetric muscle at once is another route into the loop, because it maximises the amount of new toxin in play. Dr. Croley's sequence is explicitly hierarchical: "We look at the muscles that were impacted. We prioritise which ones matter the most. Start conservatively using low doses of our neurotoxin, place it according to muscle size, strength, the role of the risk, and then reassess the patient in two weeks."
Prioritisation means asking which single muscle contributes most to what the patient actually objects to. Often that is one muscle, not four. Treating that one, below your usual dose, and reassessing is a shorter path to acceptable symmetry than a comprehensive plan that you then have to unwind.
The goal conversation comes before the dose
You cannot choose a corrective dose without knowing what you are correcting toward, and those are genuinely different targets.
"We need to talk to the patient about their goal. So are we trying to totally correct this, or are we trying to make this perfectly symmetrical? Are we trying to minimise the appearance of the asymmetry?"
Dr. Croley's worked example makes the stakes concrete. Consider an inadvertent depressor labii inferioris effect: one side of the lower lip does not move when the patient smiles. You can make that smile symmetric — by treating the other depressor labii inferioris. "Yes, we can make your smile symmetric," he tells patients, "but it may not look natural until we let this wear off."
Symmetric and natural are not the same goal, and in correction you frequently have to choose. A patient with a wedding or a photo shoot in nine days may rationally prefer symmetric-but-static. A patient with nothing on the calendar is usually better served by minimising the asymmetry and letting the rest resolve. "Maybe it's a let's watch and let's let this wear off, without continuing to chase that movement."
Have that conversation before you pick up the syringe, because the answer changes both the dose and whether you inject at all. Two further pieces of history belong in the same conversation: "Have they had any prior similar complications? How was it treated? What was their response?" A patient who ran long on a previous correction will run long on this one.
The patient also needs to understand what correction involves anatomically. "We are usually treating muscles that we would not normally treat," Dr. Croley notes. That is a meaningful consent point, and it is the kind of specific risk discussion worth having documented in your consent materials.
Breaking a loop you are already in
If you are three corrections deep with a patient, adding a fourth small dose is rarely the answer. The way out is usually to stop.
- Stop adding toxin and let the system decay. Every effect in play has a finite duration. If you stop injecting, they will all eventually resolve, and the face returns to baseline. Continuing to inject is the only thing preventing that.
- Re-baseline in writing. Photograph at rest and with animation, and document which effects you believe are still active and roughly when each was placed. You cannot manage overlapping clocks you have not written down.
- Reset the goal. Most loops are sustained by an implicit goal of perfect symmetry, which is not achievable in a face and is certainly not achievable while multiple doses are decaying at different rates.
- Set the next treatment interval deliberately. When the patient is back to baseline, the whole cycle is an opportunity to revisit the original dosing that caused it. If a frontalis dose or a lower-face plan produced diffusion once, it can produce it again.
What changes on Monday
Three things, and they are small.
Write two dose figures in your notes for any muscle you treat regularly: your treatment dose and your correction dose, with the correction dose materially lower. Deciding that in advance stops you from reaching for the familiar number in the room.
Ask the goal question before you draw up. Symmetric or natural — the patient gets to choose, and the choice changes the plan.
And treat the first corrective injection as a probe rather than a solution, with a reassessment already booked. The facial mapping reference is a reasonable orientation to the regions involved, but the dose decision is a judgement about muscle strength in front of you, not a chart lookup.
These figures and this approach reflect Dr. Chris Croley's clinical practice as taught in Empire Medical Training's hands-on curriculum. Technique is learned under supervision; this article is educational and is not a substitute for training.
Correction work sits at the harder end of neurotoxin practice because it requires dosing muscles that are not on any label, in a face that already has active toxin in it. Empire covers the foundation in Complete Botox Training and the advanced material in Advanced Botulinum Toxin & Filler Training.
Frequently Asked Questions
Why not just use my normal dose when correcting an asymmetry?
Because the two sides are on different clocks. The unintentionally affected side received a partial dose and will recover relatively quickly; a full corrective dose on the other side will outlast it. The result is the same asymmetry reversed, lasting longer than the original. Dr. Croley teaches starting below your usual dose for that muscle specifically to avoid this.
How many units below my usual dose should I go?
The right dose depends on muscle size, muscle strength, how much toxin reached the affected side, and how far that effect has already decayed — which is why Dr. Croley teaches it as a direction rather than a number. Go under your usual dose for that muscle, distribute where the anatomy allows, and reassess rather than finish.
Is it ever right to do nothing about a visible asymmetry?
Frequently. If the asymmetry is mild, the patient has no fixed timeline, and the affected side is expected to recover ahead of the treated side, watchful waiting resolves the problem without adding toxin. Dr. Croley explicitly offers this as an option: let it wear off rather than continuing to chase the movement.
Can I make a smile symmetric after an inadvertent depressor effect?
Usually yes, by treating the opposite muscle — but the result is symmetric rather than natural, because both sides are now weakened. Dr. Croley frames this as a patient choice driven by their calendar. A patient with an imminent event may want it; a patient without one is generally better served by waiting.
Why does the published case use fourteen units?
The number reflects one patient's muscle mass, prior dosing and goals, and Dr. Croley is explicit that it is not the lesson. What transfers is the placement logic — which muscles were prioritised, why a reduced dose was chosen, and why the mentalis was fractionated across the muscle rather than deposited in one point.
Disclaimer
This article reflects the clinical opinions and experience of Dr. Chris Croley, Chief Medical Officer, Empire Medical Training, an independent faculty member contributing to Empire Medical Training's curriculum. The views expressed are the author's own and do not necessarily represent those of Empire Medical Training.
It is professional education, not medical advice, and is no substitute for hands-on training or independent clinical judgment. Licensed clinicians remain responsible for their own patient selection, technique and outcomes, for verifying current product labelling, and for practising within their scope and applicable law. Empire Medical Training accepts no liability for reliance on this content.
