How can an old facial injection be assessed when its contents are unknown?
If you do not know what was injected into your face years ago, ultrasound
may suggest the general type of material, but precise identification is difficult.
For that reason, we recommend first attempting to dissolve it with hyaluronidase injections.
Why ultrasound cannot reliably identify the exact material
Different materials may have similar appearances on ultrasound.
Water-rich gels such as hyaluronic acid and polyacrylamide may both appear as dark, rounded, fluid-like lesions.
PMMA and calcium-based fillers can also produce bright reflections or shadows, making them difficult to distinguish clearly using ultrasound images alone.
Even the same calcium-based filler may look different on ultrasound depending on dilution or whether it is mixed with hyaluronic acid.
If different types of filler were repeatedly injected at different times, their ultrasound patterns may overlap, making precise identification even more difficult.
Ultrasound findings therefore usually allow an assessment such as suspected hyaluronic acid filler or suspected particulate permanent filler, rather than identification of an exact product or ingredient.
When more precise identification is needed, pathological examination or separate compositional analysis of removed tissue or foreign material may be considered.
[ Ultrasound images obtained at UVOM ]
Q. What can ultrasound assess?
Ultrasound can help assess the following.
- The suspected location and depth of residual foreign material
- Tissue findings suggestive of a granuloma
- Whether there is excessive tissue growth
- Possible inflammation caused by foreign material
Ultrasound can help distinguish findings such as granulomas and inflammation, identify the suspected location and depth of residual material, and guide planning of the removal site.
However, imaging findings alone cannot establish exactly what material was injected years ago.
If removal is desired, identifying the location and current condition of the material remaining in the face is therefore more important than determining its exact composition.
Q. Why might material remain after dissolving injections?
1. The injected material was not hyaluronic acid
Besides hyaluronic acid fillers, injections may contain semipermanent fillers, collagen fillers, or illegally injected foreign materials of unknown composition.
Hyaluronidase is an enzyme that acts on hyaluronic acid, so materials with other compositions are unlikely to dissolve even after repeated injections.
2. Multiple ingredients were mixed
All fillers contain hyaluronic acid, but some semipermanent fillers and collagen boosters also contain other ingredients.
When hyaluronic acid filler is combined with other materials, dissolving injections may reduce some of the volume while leaving the nondissolvable material in place.
3. Hyaluronic acid filler was used, but granulomas or inflammatory tissue are also present
If the injected area repeatedly swells or becomes red, painful, or warm, an inflammatory reaction to foreign material may have produced granulomas or inflammatory nodules. Both the remaining material and the surrounding tissue must be assessed.
UVOM Plastic Surgery's approach
- First assess for dissolvable hyaluronic acid filler
When the material is unknown, we advise hyaluronidase injections first rather than proceeding directly to surgery.
After reducing any dissolvable hyaluronic acid filler, we assess the remaining material to decide whether surgical removal is appropriate.
- Locating foreign material with ultrasound
If lumps or a foreign-body sensation remain after dissolving injections, ultrasound helps assess the tissue layer containing the material and how far it has spread.
We assess granulomas, inflammation, and adhesions to surrounding tissue before planning which areas to remove and how to approach them.
- Surgical removal with consideration for normal tissue
Old foreign material may be intermingled with normal fat and muscle. Aggressive removal can cause adverse effects such as facial hollowing or surface irregularities, so a careful approach is needed.
We aim to separate removable foreign material and altered tissue while preserving as much surrounding normal tissue as possible.
[ Microscopic pathological examination of semipermanent filler removed during surgery ]
Frequently asked questions
Q. How many dissolving injections are needed if the material is unknown?
A. If lumps and a foreign-body sensation remain after an adequate course of dissolving treatment determined by a clinician, surgical removal may be worth considering.
Q. Does any material remaining after dissolving injections always require surgery?
A. If residual foreign material causes recurrent inflammation and deformity, surgery may be considered to directly identify and remove the remaining material and altered tissue.
For semipermanent filler, surgical excision may be considered as one way to directly identify and remove foreign material.
Q. Can testing the removed tissue identify its exact composition?
A. Pathological examination of removed tissue can identify reactions around foreign material, such as inflammation, granulomas, and fibrosis.
These findings may suggest the type of material, but identifying the exact brand may be difficult.
If you had facial injections years ago, do not know what was used, and would like to discuss removal,
first receive injections to dissolve hyaluronic acid filler at a medical facility,
then call 02-545-3700, contact UVOM Plastic Surgery on KakaoTalk, or visit for a consultation and assessment.