Quick Answer
Hyaluronic acid filler is a gel form of hyaluronic acid — a polysaccharide naturally produced by the body — that has been cross-linked using technology to form a gel. It corrects volume losses in the skin, reduces wrinkles, and defines facial contours. Its effect lasts 6–18 months and can be dissolved with the hyaluronidase enzyme when required. More than 15 million hyaluronic acid filler procedures are performed worldwide each year, representing 78% of the non-invasive aesthetics market.
What Is Hyaluronic Acid (HA)?
Hyaluronic acid (HA) is a glycosaminoglycan polysaccharide molecule that occurs naturally in the human body and plays a critical role in skin moisture balance, joint lubrication, and tissue repair. A single HA molecule can hold up to 1,000 times its own weight in water, making it nature's most powerful moisturizing compound.
Hyaluronic acid performs the following functions in the body:
- Moisturises the skin and maintains its elasticity
- Lubricates joint fluids and acts as a shock absorber
- Accelerates wound healing
- Supports collagen synthesis
- Contributes to cell renewal
As we age, the body reduces HA production. Production begins to decline from age 25; by around age 50, the amount of HA in the body has fallen to approximately half the youthful level. This reduction leads to dryness, fine lines, volume loss, and sagging. Research shows that between ages 30–50, HA concentration in the skin decreases by 50%, and this loss continues at approximately 1–2% per year.
Effect of HA Molecular Weight on Results
Molecular weight (in daltons) is one of the most critical factors directly affecting filler performance. HA molecules are classified as low, medium, and high molecular weight:
| Molecular Weight | Dalton Range | Properties | Clinical Use |
|---|---|---|---|
| Low MW | < 500 kDa | Rapid absorption, anti-inflammatory effect, skin renewal | Mesotherapy, skin radiance, fine lines |
| Medium MW | 500–1,500 kDa | Balanced moisture retention, moderate volume | Superficial wrinkles, lip contouring |
| High MW | > 1,500 kDa | Long-lasting, strong volume formation | Deep folds, cheek and chin volume restoration |
Low molecular weight HA penetrates tissue more quickly but is broken down faster in the body; it is therefore preferred for mesotherapy and skin renewal. High molecular weight HA forms a denser gel, provides strong volume support, and maintains its effect for up to 12–18 months. Filler manufacturers combine HA chains of varying weights in different ratios to formulate products specific to each treatment area.
How Does Hyaluronic Acid Filler Work?
Hyaluronic acid filler contains HA gel synthesized in the laboratory and stabilized with cross-linking technology; when injected, it works through three key mechanisms: volume creation, water retention, and collagen stimulation. Clinical studies show that HA fillers draw water from surrounding tissue in the first 72 hours after injection, increasing their volume by 10–15%.
- Volume creation: The injected gel instantly creates volume at the target site and fills sunken areas. Clinical measurements show that an average of 0.5–1 cc of filler provides 2–4 mm of tissue elevation.
- Water retention: HA molecules draw water from surrounding tissue, progressively increasing fullness. This osmotic effect allows the filler to reach its final shape within the first 2–4 weeks.
- Collagen stimulation: In the long term, fibroblast cells are stimulated to encourage natural collagen production. Research shows that collagen type I and type III synthesis increases by 20–30% after HA injection.
Key advantage: Hyaluronic acid-based fillers are reversible. If results are unsatisfactory or a complication develops, they can be completely dissolved with the hyaluronidase enzyme. This feature is the most important safety factor distinguishing HA fillers from other filler types (such as calcium hydroxyapatite or poly-L-lactic acid).
Cross-Linked vs. Non-Cross-Linked HA
Cross-linked HA filler has a gel structure stabilized by chemical cross-linking with BDDE; non-cross-linked HA consists of free molecules and is absorbed more quickly. Cross-linking extends the residence time of HA in tissue from 24–48 hours to months and preserves the structural integrity of the filler.
| Property | Cross-Linked HA | Non-Cross-Linked HA |
|---|---|---|
| Structure | Chemically bonded stable gel with BDDE | Free HA molecules, fluid consistency |
| Longevity | 6–18 months | 24–72 hours |
| Use | Filler (volume, contouring) | Mesotherapy, skin hydration |
| Volume effect | Marked | Minimal |
| Dissolvability | Dissolved with hyaluronidase | Absorbed naturally |
| Injection depth | Subdermal / supraperiosteal | Intradermal |
BDDE Cross-Linking Chemistry Explained Simply
BDDE (1,4-butanediol diglycidyl ether) is the gold standard cross-linking chemical used in hyaluronic acid filler production, with a clinical safety history of over 20 years. BDDE builds bridges between HA chains to create a three-dimensional gel network.
The working principle of BDDE:
- Bonding: The BDDE molecule chemically bonds to hydroxyl groups on two different HA chains
- Network formation: These bonds link the HA chains together, creating a three-dimensional gel matrix
- Stabilization: The resulting network structure increases resistance to breakdown by enzymes (hyaluronidase)
- Longevity: As the degree of cross-linking increases, the residence time of the filler in tissue lengthens
The cross-linking ratio (MoD – Modification Degree) determines the clinical properties of the product. A low MoD (2–4%) produces softer, more natural results; a high MoD (6–10%) yields firmer, longer-lasting fillers. The Teoxane RHA series has the lowest cross-linking ratio on the market at 2% MoD, enabling better adaptation to natural facial movements.
G Prime (Elasticity) and Cohesivity Explained
G prime (G') is a rheological parameter that measures the stiffness of the filler and its resistance to external force; a high G prime value means a firmer gel, preferred for volume projection in deep areas. Cohesivity refers to how well the filler gel holds together internally.
G Prime (Gel Stiffness)
G prime value is the most important technical parameter determining where a filler should be used:
| G Prime Level | Value Range (Pa) | Appropriate Area | Example Products |
|---|---|---|---|
| Low G' | < 100 Pa | Lips, under eye, fine lines | Volbella, Belotero Soft |
| Medium G' | 100–300 Pa | Nasolabial fold, lip volume | Volift, Restylane |
| High G' | > 300 Pa | Cheeks, chin, nose | Voluma, Restylane Lyft |
Cohesivity (Gel Integrity)
Cohesivity is the property by which the filler gel maintains its integrity without fragmenting. Fillers with high cohesivity:
- Spread evenly within tissue and prevent surface irregularities
- Maintain their shape under mechanical stress
- Reduce the risk of filler migration
- Support natural tissue contour
Two products with the same G prime value may perform differently clinically due to different cohesivity levels. An experienced physician therefore evaluates both G prime and cohesivity values together when selecting a product.
Vycross vs. Hylacross vs. OBT Technology Comparison
Vycross, Hylacross, and OBT are the core manufacturing technologies representing three major filler producers' different cross-linking approaches; each offers a different molecular weight distribution, gel structure, and clinical performance. Understanding these technologies is critically important for appropriate product selection.
| Property | Vycross (Allergan) | Hylacross (Allergan) | OBT (Galderma) | RHA (Teoxane) |
|---|---|---|---|---|
| Molecular weight | Mixed (low + high) | Single type (high) | Variable size | Close to natural |
| Cross-linking type | Chemical BDDE | Chemical BDDE | Chemical BDDE | Minimal BDDE |
| Gel structure | Monophasic | Monophasic | Biphasic-monophasic | Monophasic |
| Swelling rate | Low-medium | High | Low | Low |
| G prime range | Wide | Narrow | Wide | Medium |
| Longevity | 12–24 months | 6–12 months | 6–18 months | 9–15 months |
| Product family | Voluma, Volift, Volbella | Juvederm Ultra | Restylane, Defyne, Kysse | RHA 2, 3, 4, Redensity |
Vycross Technology (Allergan/Juvederm)
Vycross is a technology that combines HA chains of different molecular weights in specific ratios. The combination of low- and high-weight chains provides strong structural integrity even at lower HA concentrations. Vycross products show less swelling after implantation and offer more predictable results.
Hylacross Technology (Allergan/Juvederm — Older Generation)
Hylacross is a classic technology that combines same-weight HA molecules with dense cross-linking. It has a higher water absorption capacity, so more swelling may occur after injection. The Juvederm Ultra series is produced with this technology.
OBT — Optimal Balance Technology (Galderma/Restylane)
OBT is a technology that can independently adjust the size of gel particles and binding tightness. This flexibility enables the Restylane family to offer a wide product range. OBT products are known for their low swelling rate and natural feel. XpresHAn technology (Defyne, Refyne) is an advanced version of this platform.
Monophasic vs. Biphasic Filler Differences
Monophasic filler has a homogeneous single-phase gel structure providing even distribution and natural feel; biphasic filler consists of two different phases (cross-linked particles + free HA) and offers more pronounced volume projection. In clinical comparisons, monophasic fillers have shown longer-lasting aesthetic improvement and lower post-injection pain rates.
| Property | Monophasic | Biphasic |
|---|---|---|
| Structure | Single-phase homogeneous gel | Two-phase (particles + carrier) |
| Tissue feel | Softer and more natural | Firmer, more pronounced |
| Distribution | Spreads evenly | Particles in varying sizes |
| Ideal area | Superficial lines, delicate areas | Deep folds, volume creation |
| Brand examples | Juvederm, Belotero | Restylane (classic) |
| Cross-linking | Chemically predominant | Physically predominant |
Teoxane RHA Collection — Detailed Review
Teoxane RHA (Resilient Hyaluronic Acid) is produced with Preserved Network Technology and has the lowest cross-linking ratio closest to the natural HA structure (2% MoD) on the market, dynamically adapting to facial movements to deliver natural results both in motion and at rest.
The key difference of the RHA series is that a gentle cross-linking process without heat is applied during production. This preserves the natural structure of the HA chains and provides higher biocompatibility within tissue. HA concentration is 15 mg/mL and MoD value is 2%, the lowest cross-linking ratio on the market (other fillers typically have MoD values of 5–10%).
RHA Product Family
| Product | G Prime | Indication | Ideal Area |
|---|---|---|---|
| RHA Redensity | Very low | Fine lines, skin quality | Periorbital, forehead fine lines |
| RHA 2 | Low-medium | Superficial wrinkles | Lips, perioral lines |
| RHA 3 | Medium | Moderate-depth wrinkles | Nasolabial fold, mouth corners |
| RHA 4 | High | Deep folds, volume | Cheeks, jawline |
The RHA series has demonstrated a patient satisfaction rate of over 90% in clinical studies, with an effect lasting 12–15 months.
Brand Comparison: Juvederm, Restylane, Teoxane, Belotero
Juvederm (Allergan), Restylane (Galderma), Teoxane, and Belotero (Merz) are four major FDA- and CE-approved HA filler brands, each with different technology, product range, and clinical advantages. Over 85% of the global filler market is served by these four brands.
| Criterion | Juvederm | Restylane | Teoxane | Belotero |
|---|---|---|---|---|
| Manufacturer | Allergan (AbbVie) | Galderma | Teoxane | Merz |
| Technology | Vycross / Hylacross | NASHA / OBT | RHA | CPM |
| HA source | Bacterial fermentation | Bacterial fermentation | Bacterial fermentation | Bacterial fermentation |
| Number of products | 7+ | 8+ | 5+ | 4+ |
| Standout feature | Wide G prime range | Low swelling rate | Dynamic adaptation | Skin integration |
| FDA approval | Yes | Yes | Yes (2022+) | Yes |
Area-Specific Product Recommendations
Since each facial area requires different rheological properties, correct product selection is the fundamental key to natural and long-lasting results. The table below presents recommendations based on clinical experience and current literature.
| Area | Recommended Products | Volume (cc) | G Prime Preference | Injection Depth |
|---|---|---|---|---|
| Lips | Volbella, Restylane Kysse, RHA 2 | 0.5–1 cc | Low | Submucosal |
| Nasolabial | Volift, Restylane Defyne, RHA 3 | 0.5–1.5 cc (each side) | Medium | Subdermal |
| Cheeks | Voluma, Restylane Lyft, RHA 4 | 1–2 cc (each side) | High | Supraperiosteal |
| Jawline | Volux, RHA 4 | 1–2 cc (each side) | Very high | Supraperiosteal |
| Under eye | Belotero Soft, Volbella, RHA Redensity | 0.3–0.5 cc | Very low | Sub-orbicularis |
| Forehead/temples | Voluma, Restylane Lyft | 1–3 cc | Medium-high | Supraperiosteal |
| Nose | Voluma, RHA 4 | 0.3–0.8 cc | High | Supraperiosteal |
Treatment Areas and Volumes
Hyaluronic acid filler can be applied to more than 15 areas of the face; the most frequently chosen areas are the nasolabial fold, lips, cheeks, jawline, and under eyes. The volume to be applied varies according to the area, the patient's age, and the degree of volume loss.
| Area | Average cc | Sessions | Longevity | Pain Level |
|---|---|---|---|---|
| Nasolabial fold | 1–2 cc (total) | 1 | 9–12 months | 3/10 |
| Lip augmentation | 0.5–1 cc | 1 | 6–9 months | 5/10 |
| Cheek volume | 2–4 cc (total) | 1–2 | 12–18 months | 2/10 |
| Under eye | 0.5–1 cc (total) | 1 | 9–12 months | 4/10 |
| Jawline | 2–4 cc (total) | 1–2 | 12–18 months | 3/10 |
| Temple filler | 1–3 cc (total) | 1 | 12–15 months | 2/10 |
| Non-surgical nose | 0.3–0.8 cc | 1 | 12–15 months | 4/10 |
| Chin tip | 0.5–1.5 cc | 1 | 12–15 months | 3/10 |
| Marionette lines | 0.5–1.5 cc (total) | 1 | 9–12 months | 3/10 |
How Is It Applied? Step-by-Step Process
Hyaluronic acid filler treatment is performed under sterile conditions after topical anesthesia or nerve block, using a fine cannula or needle; the procedure generally takes 15–45 minutes to complete. Safety and naturalness are prioritized at every stage of the procedure.
- Consultation (10–15 min): Facial analysis, photography, goal-setting, and product selection
- Cleansing: Sterilization of the treatment area with antiseptic solution
- Anesthesia (15–20 min): Topical anesthetic cream or dental nerve block
- Marking: Injection points identified with a surgical marker
- Injection: Filler applied into tissue with a cannula or needle
- Moulding: Shaping the injected filler with the fingertip (molding)
- Check: Symmetry assessment and additional touches if needed
- Cold compress: Ice application to reduce swelling and bruising risk
Filler vs. Botox: What Is the Difference?
Filler works by restoring volume loss and filling wrinkles; Botox temporarily blocks muscle movements to reduce dynamic wrinkles. The two procedures are not alternatives to each other — they are complementary in most cases. More than 60% of patients prefer both procedures together.
| Criterion | HA Filler | Botox |
|---|---|---|
| Mechanism | Volume creation, water retention | Muscle paralysis (neurotoxin) |
| Target | Static wrinkles, volume loss | Dynamic wrinkles (expression lines) |
| Duration | 6–18 months | 3–6 months |
| Result onset | Immediate | 3–14 days |
| Reversibility | Yes (hyaluronidase) | No (resolves over time) |
| Treatment areas | Nasolabial, lips, cheeks, chin | Forehead, crow's feet, glabella |
Vascular Occlusion Risk and Emergency Protocol
Vascular occlusion is obstruction of tissue nutrition following blockage of an artery or vein by filler material, and is the most serious filler complication requiring immediate intervention. Incidence is reported at approximately 1/6,000–1/10,000 procedures, but permanent damage can be prevented with early diagnosis and correct management.
Signs of Vascular Occlusion
- Sudden blanching at the injection site
- Severe, disproportionate pain
- Livedo reticularis (net-like purple discolouration)
- Coldness and numbness in the area
- Dark purple/blue discolouration within hours
Emergency Management Protocol (CMAC Guidelines)
- Stop the injection immediately
- Inject hyaluronidase — 1,500 units/mL per angiosome, repeat every 20 minutes
- Apply nitroglycerin patch or cream (for vasodilation)
- Give Aspirin 325 mg orally
- Apply warm compress (to increase vasodilation)
- Check arterial flow with handheld Doppler
- Obtain ophthalmological assessment (if visual symptoms present)
Critical time window: Administering hyaluronidase within the first 4 hours significantly improves outcomes. Ideal intervention is within 48 hours.
Filler Dissolution with Hyaluronidase
Hyaluronidase is a natural enzyme that breaks down hyaluronic acid filler and is used to correct unwanted results, asymmetries, or complications. The enzyme cleaves the glycosidic bonds in HA chains, liquefying the filler and enabling natural absorption by the body.
Filler Dissolution Indications
- Asymmetry or shape distortion
- Overfilling
- Filler migration
- Vascular occlusion (emergency)
- Tyndall effect (blue discolouration, especially under eyes)
- Nodule or nodularity
Hyaluronidase Dosing
| Situation | Recommended Dose | Repeat |
|---|---|---|
| Minor correction | 30–75 units | After 2 weeks if needed |
| Moderate correction | 150–300 units | Review after 24–48 hours |
| Vascular occlusion | 1,500 units/angiosome | Repeat every 20 minutes |
| Complete dissolution | 300–600 units | May require 2–3 sessions |
Important: An allergy test is recommended before hyaluronidase administration. The enzyme can also break down natural HA; therefore, temporary volume loss may occur in the area after dissolution. Natural HA is generally resynthesized within 2–4 weeks.
Filler Migration: Causes and Prevention
Filler migration is displacement of the injected material from its original location to another area; it is most commonly seen in the lips, under eyes, and nasolabial region. Migration is preventable, and with correct technique and product selection the risk can be reduced to below 1%.
Causes of Migration
- Excessive filler volume: Injecting too much product in a single session increases tissue pressure, causing the filler to shift
- Incorrect injection depth: Overly superficial injection, particularly in the lips, leads to outward displacement
- Low-cohesivity product selection: Products with poor gel integrity move more easily within tissue
- Facial movements: Repetitive movements such as frequent talking and chewing may gradually contribute to migration
- External pressure: Applying pressure to the area early after the procedure (sleeping face-down, massage)
Prevention Strategies
- Gradual application: Do not exceed the maximum volume in a single session; plan a second session 2–3 weeks apart if necessary
- Correct product selection: Choose a product with G prime and cohesivity values appropriate for the area
- Correct depth: Determine the injection depth appropriate to the anatomical plane
- Post-procedure instructions: Do not touch the area for the first 48 hours; avoid sleeping face-down
Overfilled Face Correction
An overfilled face refers to a condition where repeated or excessive filler treatments have distorted natural facial proportions, appearing swollen and artificial. With growing awareness in recent years, "filler deflation" procedures have increased by 40%.
Signs of an Overfilled Face
- Pillow face: Cheeks appearing excessively plump and pillow-like
- Duck lips: Lips disproportionately large and projecting forward
- Sausage lips: Upper and lower lip borders becoming indistinct
- Heavy face: Face appearing pulled downward and heavy
- Loss of expression: Restricted facial movements
Correction Approach
- Gradual dissolution: Progressive dissolution of excess filler with hyaluronidase (sessions spaced 2–4 weeks apart)
- Waiting period: Waiting 4–6 weeks after dissolution for natural HA to be resynthesized
- Strategic re-application: Re-filling in minimal volumes consistent with natural proportions
- Holistic approach: Combined plan incorporating Botox and skin care, not filler alone
How Long Does Filler Last?
The effect of hyaluronic acid filler lasts 6–18 months depending on the product, area, and individual metabolism; longevity is shorter in high-movement areas (such as lips) and longer in low-movement areas (such as cheeks and temples). Metabolic rate, smoking, and sun exposure are the main factors affecting longevity.
| Area | Average Longevity | Influencing Factors |
|---|---|---|
| Lips | 6–9 months | High movement, thin tissue |
| Nasolabial | 9–12 months | Moderate movement |
| Cheeks | 12–18 months | Low movement, deep injection |
| Jawline | 12–18 months | Low movement |
| Under eye | 12–18 months | Low movement, thin tissue |
| Temples | 12–18 months | Very low movement |
| Nose | 12–18 months | Low movement |
Side Effects and Risk Management
The most common side effects of hyaluronic acid filler are redness, swelling, and bruising, which generally resolve on their own within 3–7 days; serious complications (0.01–0.1%) include vascular occlusion, infection, and granuloma formation. Experienced physician selection, a sterile environment, and correct product use are the determining factors in risk management.
Common Side Effects (Mild — 60–80% incidence)
- Redness: 1–3 days
- Swelling (oedema): 2–5 days
- Bruising (ecchymosis): 5–10 days
- Tenderness: 3–7 days
- Mild asymmetry: First week (swelling-related, generally resolves)
Rare Side Effects (Serious — 0.01–0.1%)
- Vascular occlusion: Emergency hyaluronidase required
- Infection: Antibiotic treatment
- Granuloma: Steroid injection or surgery
- Tyndall effect: Correction with hyaluronidase
- Biofilm: Long-term antibiotics + hyaluronidase
Contraindications
Hyaluronic acid filler is contraindicated in active skin infection, autoimmune diseases, during pregnancy/breastfeeding, and in known HA allergy. Patients on blood thinners also require physician consultation before the procedure.
- Active skin infection (herpes, acne, cellulitis) in the area
- Pregnancy and breastfeeding
- Known HA or BDDE allergy
- Autoimmune diseases (active phase)
- Anticoagulant therapy (relative contraindication)
- Permanent filler present in the same area
- Active keloid or hypertrophic scar history
- Patients under immunosuppressive therapy
Post-Procedure Care Guide
The first 48 hours after filler are a critical recovery period; the area should not be touched, intense exercise should be avoided, and hot environments (sauna, hammam) should be avoided. Proper care directly affects the quality and longevity of results.
First 24 Hours
- Do not touch the area or massage it
- Do not apply makeup
- Avoid blood thinners such as aspirin and ibuprofen
- Apply cold compress (10 minutes on, 10 minutes off)
- Drink plenty of water
First Week
- Avoid intense exercise
- Avoid sauna, hammam, and hot baths
- Limit alcohol consumption
- Avoid sun exposure
- Postpone dental treatment (after lip/nasolabial filler)
Long-Term Care
- Use SPF 50 sunscreen daily
- Establish a skin care routine with retinol and vitamin C serum
- Moisturise regularly
- Schedule a check-up appointment every 6–12 months
Golden Rules for Natural Results
The four most important rules for achieving a natural-looking filler result are the "less is more" principle, respect for facial proportions, gradual application, and holistic planning. Research shows that the highest patient satisfaction is achieved with a "change that goes unnoticed" approach.
- Less is more: Avoid exaggerated volumes in a single session; gradual increase is always safer
- Maintain facial proportions: Plan in accordance with the golden ratio and the facial thirds rule
- Age-appropriate approach: The same volume should not be applied to a 25-year-old and a 50-year-old patient
- Holistic planning: Assess the whole face rather than a single area; consider cheek volume restoration + nasolabial combination rather than nasolabial filler alone
- Correct product selection: Choose a product with G prime, cohesivity, and longevity properties appropriate for the area
- Manage patient expectations: Set realistic, natural goals rather than an "Instagram face"
Pricing (2026)
Hyaluronic acid filler prices vary depending on the brand used, the area to be treated, and the volume in cc. Please contact us for current pricing information at Virtuana Clinic.
Frequently Asked Questions
1. Is hyaluronic acid filler painful?
Topical anesthetic cream or a nerve block is applied before hyaluronic acid filler treatment. Most modern filler products also contain lidocaine. 85% of patients rate the pain at 3/10 or below. Cannula use further reduces pain compared to a needle.
2. When are results seen after filler?
Results are visible immediately after filler. However, the true result cannot be assessed for the first 2–5 days due to swelling. The filler takes its final shape over 2–4 weeks as the HA draws water from the surrounding tissue to reach optimal volume.
3. Will my face swell after filler?
Yes, mild-to-moderate swelling is a normal and expected side effect. Swelling generally subsides significantly within 2–5 days. Lip filler swelling may be more pronounced than in other areas. Cold compresses help reduce swelling.
4. What is the difference between cross-linked and non-cross-linked filler?
Cross-linked HA is a gel stabilized by chemical cross-linking with BDDE and remains effective for 6–18 months. Non-cross-linked HA consists of free molecules, is more fluid in consistency, and is absorbed within 24–72 hours. Cross-linked fillers are used for volume creation, while non-cross-linked forms are used for skin hydration (mesotherapy).
5. Does filler dissolution (hyaluronidase) hurt?
Hyaluronidase injection causes mild discomfort similar to filler injection. Topical anesthetic is applied beforehand. The dissolution process is completed within 10–15 minutes and the filler largely dissolves within 24–48 hours.
6. Can I exercise after filler?
Intense exercise should be avoided for the first 24–48 hours after filler. Activities that raise blood pressure may increase the risk of swelling and bruising. Light walking is fine, but weightlifting, running, and swimming should not begin until after 48 hours.
7. Can filler and Botox be done in the same session?
Yes, filler and Botox can be administered in the same session — this combination is called a "liquid facelift." Botox treats dynamic wrinkles (forehead, crow's feet), while filler treats static lines and volume loss. The combined approach provides 30–40% higher patient satisfaction.
8. How do you recognize filler migration?
Filler migration presents as abnormal fullness, nodularity, or distortion outside the injection area. It can be noticed especially in lip filler as a "mustache line" prominence above the upper lip. If migration is suspected, consult your physician; ultrasound can confirm it.
9. Can filler be administered during pregnancy?
No, hyaluronic acid filler is contraindicated during pregnancy and breastfeeding. Although HA is a naturally occurring substance, there are insufficient clinical studies on its safety during pregnancy. Filler can be administered 3 months after breastfeeding has ended.
10. From what age can filler be administered?
Hyaluronic acid filler is generally performed in individuals aged 18 and above. The most commonly preferred age range is 25–55. In younger patients, lip and chin contouring are typically prioritised, while volume restoration is more common in patients over 40.
11. What does G prime value mean and why is it important?
G prime (G') measures the stiffness of the filler gel. Fillers with a high G prime (e.g. Voluma, >300 Pa) provide strong volume projection in deep areas. Low G prime fillers (e.g. Volbella, <100 Pa) give more natural results in delicate areas (under eye, lips).
12. What is the key difference between Vycross and OBT technology?
Vycross (Allergan) combines HA chains of different molecular weights to achieve low swelling rates and long longevity. OBT (Galderma) can independently adjust gel particle size and binding tightness, offering a wide product range. Vycross-technology fillers last 12–24 months, while OBT products remain effective for 6–18 months.
13. Why is the Teoxane RHA series different?
Teoxane RHA has the lowest cross-linking ratio on the market at 2% MoD (other brands are in the 5–10% range). Thanks to Preserved Network Technology, the natural HA structure is preserved and the filler dynamically adapts to facial movements, producing more natural results especially in the lips and perioral region.
14. What should be done in the event of vascular occlusion?
If vascular occlusion signs appear (sudden blanching, severe pain, purple discolouration), consult your physician immediately. According to the CMAC protocol, 1,500 units of hyaluronidase are administered every 20 minutes per angiosome. Intervention within the first 4 hours significantly improves outcomes. This is why every clinic performing filler must have hyaluronidase available.
15. How is an overfilled face corrected?
An overfilled face is gradually corrected with hyaluronidase. Excess filler is progressively dissolved over sessions spaced 2–4 weeks apart. After dissolution, 4–6 weeks are waited for natural HA to be resynthesized. New filler can then be planned in minimal amounts consistent with natural proportions.
This article is for informational purposes only. Please consult a qualified physician for treatment decisions.