Botulinum toxin in facial harmonization: planning basics

Botulinum toxin is one of the most frequently performed procedures in orofacial harmonization (HOF) and, at the same time, one of the most underestimated. Because it is quick to inject, it seems simple. But the result depends on understanding the mechanism, reading each patient's muscle dynamics and planning the face as a set of forces that balance each other.

This guide gathers the fundamentals of planning, at review level. It does not give doses per muscle, injection points or dilutions: those decisions belong to the qualified professional, based on the product label, guidelines and the rules of their professional council in Brazil.

How does botulinum toxin work?

Botulinum toxin temporarily blocks the release of acetylcholine at the neuromuscular junction. Without that signal, the treated muscle contracts less. The effect is not immediate: it depends on the toxin being internalized and the release mechanism being interrupted, and it sets in over a few days.

Over time, the nerve terminal forms new connections and function returns. That is why the effect is temporary and the treatment is, by nature, one of maintenance.

The timelines vary with the product, the dose, the muscle, muscle strength and each patient's metabolism. When explaining, say "in general" and never promise a guaranteed timeframe.

Dynamic and static wrinkles: why does the difference matter?

The distinction between dynamic wrinkles and static wrinkles defines what the toxin can and cannot do.

During the assessment, observe the face at rest and in motion. Ask for the same expressions that will be photographed (frowning, raising the eyebrows, smiling) and note what disappears when the muscle relaxes. This aligns expectations: if the wrinkle is present at rest, the patient needs to know that the toxin alone may not erase it.

Why are units not interchangeable?

The toxin dose is expressed in units, which measure biological activity, not mass or volume. Each manufacturer defines its unit by its own assay. So, as the toxin unit entry explains, units from different products are not interchangeable or convertible by a simple rule.

Practical consequences:

• the number of units only makes sense together with the product name;
• switching products requires reviewing the plan based on the label, not applying a conversion;
• the dilution volume changes the concentration, not the dose;
• the patient record should note product, lot, dilution and units per point.

What should be considered when planning?

Toxin planning is, above all, a reading of forces. Each muscle you weaken changes the balance with its antagonists.

Muscle strength and contraction pattern

Patients with stronger musculature often need different planning from those with more delicate musculature. The contraction pattern also varies: two people with the same wrinkle in the glabella may have different movement patterns, which call for a different distribution, at the professional's discretion.

Balance between elevators and depressors

In the upper third, the frontalis muscle raises the eyebrows and the glabellar muscles, such as the corrugator and the procerus, lower them. Treating one group and not the other, or overtreating one of them, changes the position and shape of the eyebrows. The same reasoning applies to the lower third, where the muscles that pull down the mouth corners and the chin balance against others.

Pre-existing asymmetry

Many patients have movement-related facial asymmetry, such as one eyebrow rising more than the other. Record this beforehand, with a photo and a note, and show it to the patient. An asymmetry that already existed and was not recorded tends to be blamed on the procedure.

Goal and naturalness

Some patients want the least possible movement; others want to soften lines without losing expression. Ask. The goal changes the planning and prevents complaints of a "frozen face" or of "it didn't work".

Injection history

Frequent injections and the patient's response history factor into the decision. Asking when the last injection was, with which product and how it turned out is part of the medical history in HOF.

Which areas come up most often?

Uses in other areas and for non-aesthetic purposes exist, but they require specific assessment and training and fall outside the scope of this guide.

What are the best-known risks?

Most adverse effects are mild and transient: pain at the site, a small bruise, headache. The ones patients remember most are those related to diffusion into neighboring muscles:

• eyelid ptosis, drooping of the upper eyelid;
• eyebrow ptosis, drooping of the eyebrow;
• expression asymmetry;
• an effect different from the expected one, such as an overly arched eyebrow.

These effects are temporary and tend to subside as the effect of the toxin wears off. Contraindications, such as neuromuscular diseases and drug interactions, appear on the product labels and are summarized in general contraindications in HOF. The overview of complications is in the safety overview.

How do you align the patient's expectations?

• Explain that the effect starts within a few days and stabilizes at about two weeks.
• State clearly that the effect is temporary and the treatment is one of maintenance.
• Show, with the patient making the expressions, what a dynamic wrinkle is and what a static one is.
• Schedule the follow-up for reassessment, when you can judge the need for adjustment.
• Record everything in the informed consent.

And in Harmy?

The Glabella point in Harmy is linked to the glabella toxin procedure. In Plan, the value of that area works as a reference for the simulation and does not represent the dose in units: the actual dose stays in your patient record. Because the projection is made on a static frontal photo, it shows the area smoother at rest and does not simulate movement. At the consultation, use the projection to talk about the overall look and the assessment in motion to explain what the toxin does.

How to photograph to plan the toxin?

The toxin acts on movement, and a photo at rest alone does not show what will change. To plan and compare, record:

• frontal at rest;
• frontal with a frown (glabella);
• frontal with raised eyebrows (forehead lines);
• frontal with a strong smile (periorbital region);
• when the chin is in the plan, the expression that marks the area.

Always use the same instruction and repeat it at follow-up. That way, the comparison shows the effect on movement, which is what the toxin does.

What are the most frequent planning mistakes?

• Treating the wrinkle and not the muscle. The spot where the wrinkle appears is not always the spot of greatest muscle strength.
• Forgetting the antagonist. Treating the forehead without considering the glabella, or the reverse, changes the eyebrow unpredictably.
• Not recording pre-existing asymmetries. After the procedure, the patient starts noticing what was always there.
• Promising to erase a static wrinkle. The frustration comes at follow-up.
• Converting units between products. Units are specific to each product.
• Reinjecting before the peak effect. Adjustments made too early can lead to an excessive effect; the moment to reassess is the professional's decision.
• Not asking about the last injection. Short intervals and response history change the planning.

Toxin planning checklist

1. Updated medical history, with contraindications and medications checked.
2. Standardized photos at rest and with the agreed expressions.
3. Wrinkles classified as dynamic or static, with expectations explained.
4. Pre-existing asymmetries recorded and shown to the patient.
5. Goal of naturalness agreed.
6. Product defined and label consulted; units treated as product-specific.
7. Product, lot, dilution and units per point recorded.
8. Reassessment follow-up scheduled.

To photograph movement in a comparable way, see standardized clinical photography.