The forehead is a relatively large area of the face, so even a small change in volume can noticeably change the overall impression.

 

Especially from the side, if the forehead falls flat, the area above the eyebrows looks hollow, or the curve from below the hairline to the center of the forehead is lacking, the face can look somewhat tired or appear stronger than intended.

 

However, forehead filler is not simply a procedure that adds a large amount of volume to make the forehead round.

It is closer to a treatment that gently fills only the hollow areas according to the overall facial proportion and naturally refines the side profile from the forehead to the nose.

 

*The doctor’s aesthetic sense is important.

 

Simply put, forehead filler is less about making the forehead larger and more about designing a smoother line when the forehead looks flat or hollow.

 

How did the before-and-after photos change?

 

If you look at the before-and-after photos above, before treatment, the forehead appears relatively flat from the side, and the volume above the eyebrows and in the central forehead looks somewhat lacking.

 

In this type of case, the upper face may look flatter from the side, and the overall three-dimensionality of the face may appear less defined.

 

After treatment, the curve of the front forehead appears softer, and the line from below the hairline to above the eyebrows looks more refined.

 

The important point here is that the forehead does not look excessively protruded.

 

Rather, the previously hollow areas have been restored, making the overall curve appear smoother.

 

This kind of change may be more noticeable from the side than from the front.

 

Forehead filler may sound like a procedure that dramatically changes the face, but in many cases, a small difference in curvature can make the overall impression look softer.

 

*However, since the photos above appear to show the before-and-after result on the day of the procedure, some immediate swelling or volume right after injection may be reflected.

 

How do studies explain forehead filler?

Example: forehead depression classification image or forehead augmentation technique figure

One useful paper related to forehead filler is a 2018 study by Kim.

 

This study classified forehead depression into different types and described a strategy for restoring forehead volume using calcium hydroxylapatite filler.

 

The paper explains that forehead filler may help improve forehead depression and wrinkles, but many physicians approach it cautiously because of risks such as pain, intravascular injection, skin necrosis caused by embolism, and blindness.

For example, when the structure is divided into types such as central forehead depression, bilateral depression, or depression above the eyebrows, it becomes easier to explain why the design must differ from person to person, even when the same forehead filler procedure is being performed.

 

The important message of this paper is that forehead filler is not a procedure that simply fills the center of the forehead.

 

It means that each person’s forehead depression pattern should first be classified, and volume should then be restored accordingly to create a natural line.

 

Recent studies on forehead augmentation using hyaluronic acid filler also explain that a step-by-step approach considering anatomical structure, injection layer, and vascular location is important.

A 2024 study on a five-step approach using high G prime hyaluronic acid filler proposed a method for approaching the forehead in multiple steps.

 

A 2025 review on HA fillers for the upper face also emphasized that upper-third areas such as the forehead, temples, and glabella should prioritize safety based on anatomical understanding.

 

These materials also show that forehead filler should be understood not simply as a procedure that adds volume, but as a treatment that evaluates the type of forehead depression and distributes volume while considering safe layers and injection routes.

 

This point is also important in actual clinical practice.

 

The forehead is a broad area, but it is also an area where blood vessels and nerves pass through.

 

Vessels such as the supraorbital artery and supratrochlear artery are important structures that connect the forehead and the area around the eyes.

 

That is why forehead filler requires consideration not only of the injection amount, but also the injection layer, injection pressure, injection speed, entry point, and areas with vascular risk.

 

What should you be careful about?

Temporary swelling, bruising, tenderness, unevenness, and asymmetry may occur.

 

Because the forehead is a wide area, if the filler does not spread evenly, it may feel bumpy to the touch or the surface may not look smooth under light.

 

If filler is placed too superficially, it may show through or be palpable.

 

If too much is injected at once, the forehead may look unnaturally round.

 

In particular, the forehead and glabella area require careful attention to vascular-related complications.

 

Although rare, serious problems such as vascular occlusion, skin necrosis, and visual disturbance may be reported, so sufficient explanation before and after the procedure is necessary.

 

Literature on filler complications also explains that intravascular injection or vascular compression may lead to serious outcomes such as skin ischemia, necrosis, and blindness.

After the procedure, it is better to temporarily avoid strong massage, sauna, excessive exercise, alcohol, and sleeping face down.

 

Also, if severe pain persists, the skin becomes pale or mottled, or any visual disturbance occurs, the clinic should be contacted immediately.

 

Forehead filler is a procedure that can show relatively quick changes, but safety and naturalness are especially important in this area.

 

To summarize, forehead filler may help add volume to a flat or hollow forehead and soften the side profile and upper facial line.

 

However, the important point is not adding a large amount.

 

The key is to look at how the central forehead, area above the eyebrows, temple connection, and area below the hairline connect, then create a curve that matches the overall facial proportion.

A natural change does not come from making the forehead excessively convex.

 

It comes from gently refining the previously hollow line.

 

Studies also describe forehead filler as a procedure that requires classification of forehead depression types and consideration of anatomical structures and safe injection strategies.

 

In the end, forehead filler is less about “how much is filled” and more about “how accurately the structure is assessed and how naturally the line is connected.”

 

The forehead can soften the overall impression of the face, but it is also an area that absolutely requires careful safety planning.

 

That is why it is better to structurally assess what type of forehead depression you have and how much volume is needed in which layer through consultation before proceeding :)

 

This was Director Won Dae-han.

 

Thank you for reading.

 

Source:
Kim J. Novel Forehead Augmentation Strategy: Forehead Depression Categorization and Calcium-Hydroxyapatite Filler Delivery after Tumescent Injection.
Plastic and Reconstructive Surgery—Global Open. 2018;6(9). DOI: 10.1097/GOX.0000000000001858.

Huang YL, et al.
A Five-step Approach with High G Prime Hyaluronic Acid. 2024.