Types of Dermal Filler, and How Over-Filling Happens

Most people searching for dermal fillers in Singapore are not asking whether the product works. They are asking whether it will still look like them, whether it can be undone, and why some faces come out of repeated treatment looking heavier rather than younger. None of those questions is answered by the brand on the box.

A dermal filler is a gel placed beneath the skin to occupy space. That is the whole mechanism. Everything else follows from three decisions made before the syringe is opened: which material, which tissue plane, and whether missing volume was the problem at all. Every plan is made individually at consultation.

Dermal fillers in Singapore are HSA-registered gels, most often hyaluronic acid, injected by a doctor to restore volume or structure in areas such as the cheeks, chin, temples, lips and tear troughs. A filler occupies space; it does not lift or tighten. The material, the tissue plane and whether volume is truly missing are decided at assessment.

Key Facts

What a Dermal Filler Is — and What It Is Not

A dermal filler occupies space. Placed on the bone, within the fat or within the dermis, it adds volume where volume has been lost or was never there: a flattened cheek, a short chin, a hollow temple, a low nasal bridge. It restores structure.

It is not a skin booster, which is lightly cross-linked or uncross-linked hyaluronic acid or a polynucleotide placed within the dermis to act on hydration and skin quality, without projecting or contouring. It is not botulinum toxin (BTX), which acts on muscle by reducing the contraction that folds skin into a dynamic line. A filler does nothing to a muscle, and a toxin does nothing for a hollow. Which of the three fits depends on which tissue is responsible for what you see, and that is what the examination decides.

“Everyone says they want natural results. Almost nobody can define it.”

Dr Sin YongOn what natural means · from his Instagram explainer series

The Types of Dermal Filler

Hyaluronic acid

Hyaluronic acid is a polysaccharide already present in the dermis. In a filler it is cross-linked, usually with BDDE, so the gel resists enzymatic breakdown and holds its form; concentrations are typically 15–24 mg/mL. Where a gel belongs is governed by G′, the elastic modulus: a high-G′ gel where the filler must project against bone, a low-G′ gel where tissue is thin and mobile and a firm product would show as a ridge. HA is the usual first choice because it is the one material that can be reversed.

Calcium hydroxylapatite

Radiesse is 30% calcium hydroxylapatite microspheres, 25–45 µm in diameter, in a 70% carboxymethylcellulose gel. The gel gives volume at injection; as it is absorbed, the microspheres remain as a scaffold on which fibroblasts lay down collagen. It has a higher G′ than most HA gels and cannot be dissolved with hyaluronidase.

Polycaprolactone

Ellansé works on the same principle: 30% polycaprolactone microspheres in a 70% CMC carrier. It is likewise not reversible by enzyme, so placement has to be right the first time.

Poly-L-lactic acid

PLLA is a biostimulator rather than a filler: it does not occupy space at injection but prompts fibroblasts to make collagen, and it belongs under collagen biostimulators. The materials are set side by side in the Radiesse, Ellansé and HA comparison.

The Areas — and What the Filler Is Doing in Each

• Cheek. The malar fat pads deflate and the maxilla remodels with age. A firm gel on the periosteum of the zygoma restores anterior projection where the midface catches light.
• Chin. A retruded chin shortens the lower face in profile. Supraperiosteal filler at the pogonion adds forward projection and can lengthen or narrow the chin depending on placement.
• Jawline. Filler along the mandibular border and angle sharpens the edge between face and neck. It defines a line; it does not lift a jowl sitting over it.
• Temples. Hollowing exposes the bony rim of the orbit. Filler placed deep on the bone or within the temporal fascia restores the natural convexity.
• Forehead. A flat or concave forehead is a skeletal shape, not a skin problem. A soft gel in the supraperiosteal plane restores a gentle curve, placed with the supratrochlear and supraorbital vessels in mind.
• Nose. Filler raises a low radix or camouflages a dorsal hump by adding above and below it, so the profile reads straighter. It never makes a nose smaller, and the nasal arteries make it a high-risk zone.
• Tear trough. The hollow between lower lid and cheek takes a low-G′ gel placed deep to the orbicularis in small increments; too much or too shallow shows as puffiness or a blue tint.
• Lips. Filler adds volume to the body of the lip or defines the vermilion border. The lip is mobile, so a soft gel is used and proportion to the face governs the plan.
• Hands. Loss of dorsal fat exposes tendons and veins. HA or CaHA in the dorsal subcutaneous plane restores the cushion over them.

“A filler adds volume. It does not lift, and it does not tighten. Asking it to do either is how faces end up over-filled.”

Dr Sin YongOn what a filler cannot do

The Assessment: Why the Whole Face Is Examined

Facial ageing is three processes at once: volume loss (fat-pad deflation and bone resorption), laxity (ligaments and skin losing their hold) and declining skin quality. A filler acts on the first. Given to someone whose main change is laxity, it produces a heavier lower face with the same sag. The examination separates the three, and it covers the whole face because the face is one structure: a deflated midface deepens the nasolabial fold, and filling the fold treats the shadow rather than the cause. Volume restoration is planned across the face, not per syringe.

The pillow face pattern comes from the opposite habit: the same zones filled repeatedly over years, each addition layered on product still present, without asking whether the hollowing was structural. Cumulative volume is assessed at every visit, and ultrasound is used where the history of previous filler is unclear.

Who It Suits — and Who It Does Not

Filler suits a change that is genuinely volumetric — deflated cheeks or temples, a hollow tear trough — in a face whose skin and ligaments still provide support, and shapes that were never age-related: a retruded chin, a low nasal bridge, thin lips.

Treatment is deferred in pregnancy and breastfeeding and where there is active infection at or near the site, including a cold sore. Autoimmune and inflammatory conditions are assessed individually rather than excluded outright. Previous non-resorbable fillers — silicone, PMMA — must be declared, because layering HA over them raises the risk of nodules and infection. Filler is declined where the expectation is something it cannot do: lift a jowl, tighten loose skin, make a nose smaller.

What Happens at the Appointment

The appointment begins with the examination, photographs and a plan naming the areas, the product and the plane for each. The skin is cleaned and a topical anaesthetic applied; most HA fillers also contain lidocaine. Product is delivered by needle or cannula. A needle is precise and suits small deposits placed directly on bone. A cannula is blunt-tipped, enters through a single port and glides through the subcutaneous plane, tending to push vessels aside rather than pierce them. The choice is made per area. Product is placed in small increments, moulded and checked against the other side before more is added.

Recovery

Recovery varies. Swelling, tenderness and some bruising at the entry points are expected; lips and tear troughs swell more than bony areas. Temporary asymmetry while swelling settles at different rates is common and is not a reason for more product. What warrants review is different in kind: pain out of proportion to the injection, skin that blanches, turns dusky or develops a net-like mottling, or any change in vision. These are reported the same day.

Risks, Stated Plainly

Vascular occlusion. Filler can enter or compress an artery, and the tissue it supplies loses its blood flow. The signs are blanching, dusky or net-like discolouration and pain out of proportion; in the rarest cases filler reaching the ophthalmic circulation affects vision. It is an emergency treated with high-dose hyaluronidase, which is why HA is used in the highest-risk zones and the enzyme is kept in the room.

Nodules. Non-inflammatory (product in the wrong plane or too much in one spot) or inflammatory, sometimes appearing late.

Migration. Filler can drift, most often in mobile areas like the lips and when placed too superficially or in too large a volume.

Tyndall effect. HA placed too close to the surface scatters light and reads as a blue-grey tint, particularly under the eyes.

Infection. Uncommon with sterile technique; the risk rises with previous non-resorbable filler or active skin infection nearby.

Reversibility runs through all of these. With HA a misplaced deposit can be dissolved and the plan revisited; with CaHA and PCL the alternative is waiting for resorption. That is a reason to begin with HA, not a reason to avoid the other materials where they are the right tool.

How Over-Filling Is Avoided — and Corrected

Over-filling is avoided by asking what is missing before asking what to add: structure before volume, bone before soft tissue, and a plan for the whole face rather than a count of syringes. The endpoint is proportion, not fullness.

Where previous treatment has gone too far, correction begins with high-frequency ultrasound, which shows where existing filler sits, in which plane and in what relation to vessels. Hyaluronidase is then delivered under ultrasound guidance so the excess is targeted rather than the whole area, and the face is re-assessed from the beginning. The approach is set out on the filler correction page.

What Determines the Cost

Cost is set out at consultation, once the plan exists. The factors are the areas treated and how many, what the examination finds in each, the product chosen and the quantity the anatomy calls for, whether filler is used alone or combined with toxin or a biostimulator, and whether the plan is staged across more than one visit. Correction of previous filler is costed separately from new treatment.

Watch

Dr Sin Yong explains

What "natural" means in technical terms: movement preserved, proportions unchanged, no new shapes. A short video from Dr Sin Yong’s Instagram, with captions.

Watch on Instagram: What "natural" means in technical terms: movement preserved, proportions unchanged, no new shapes.

Lip fillers in Singapore: what decides the result

Lip filler adds volume to the body of the lip, defines the border or corrects asymmetry, and the plan is built around proportion rather than size. The lips are assessed against the rest of the lower face: the ratio of upper to lower lip, the shape of the Cupid's bow, the position of the corners of the mouth, and how the lips move in speech and in a smile.

A soft, low-G′ hyaluronic acid gel is used because the lip is constantly moving and a firm product would feel and look wrong. Product goes in small amounts, and the vermilion border is treated separately from the body of the lip, because overfilling the border is what produces the shelf-like upper lip that reads as treated. Migration above the border is more likely when volume is excessive or placed too superficially.

Lips swell more than most areas, so they look fuller at first than they will once settled, and judging the result early is unreliable. A history of cold sores should be mentioned, since injection can trigger an outbreak. As with any area, cost follows the plan and is set out at consultation rather than quoted in advance.

Under-eye filler: who it suits and who it does not

Under-eye filler suits a tear trough that is a genuine hollow: a groove between the lower lid and the cheek, in skin that is not too thin, under lids that are not puffy. It is a poorer choice where the main problem is herniated orbital fat, fluid that comes and goes, marked lower-lid laxity or pigment, because filler adds volume and none of those is a shortage of volume.

Where it is appropriate, a low-G′ hyaluronic acid is placed deep, beneath the orbicularis muscle, in small increments, often by cannula. Hyaluronic acid is chosen because it can be dissolved: this is an area where the Tyndall effect, persistent swelling and vascular events are taken especially seriously, and reversibility matters. Calcium hydroxylapatite and polycaprolactone are generally avoided here.

People who already retain fluid under the eyes, or who wake with puffiness that settles through the day, tend to do less well with filler, because hyaluronic acid attracts water. In some of these cases supporting the cheek below, or addressing laxity with an energy-based approach, is the better route, and where fat herniation dominates, a surgical opinion is the honest answer.

How long do dermal fillers last?

How long a dermal filler lasts depends on the material, how densely it is cross-linked, where it is placed and the individual, so no single figure applies. Hyaluronic acid is broken down gradually by the body's own enzymes; more highly cross-linked, higher-G′ gels placed deep on bone tend to persist longer than soft gels in mobile areas such as the lips.

Imaging studies have reported hyaluronic acid filler remaining in tissue well beyond the period in which it is visible, which is one reason repeated treatment on a fixed schedule leads to accumulation. Calcium hydroxylapatite and polycaprolactone are resorbed as the carrier is absorbed and the microspheres break down, while poly-L-lactic acid acts through the collagen it stimulates rather than through the product itself.

So the question at a review is not whether it is time for more filler, but what the face needs now. Existing product is assessed first, with ultrasound where the history is unclear, and nothing is added simply because time has passed.

Options for volume loss and facial contour, compared

Option	What it does	What it cannot do	Typical recovery	Who it tends to suit
Hyaluronic acid filler	Cross-linked gel that occupies space to restore volume or projection, with G′ chosen to suit the area	Does not lift a jowl or tighten loose skin; does not act on muscle	Swelling, tenderness and possible bruising while it settles	Volume loss or shape in the cheeks, chin, temples, lips and tear troughs; the usual first choice because it can be dissolved
Calcium hydroxylapatite (Radiesse) or polycaprolactone (Ellansé)	Carrier gel gives volume; microspheres act as a scaffold for collagen as the gel is absorbed	Cannot be dissolved with hyaluronidase; generally avoided in thin, mobile areas such as the lips and tear troughs	Swelling, tenderness and possible bruising	Structural support on bone, such as the jawline, chin or cheek, where reversibility is not the priority
Poly-L-lactic acid (collagen biostimulator)	Prompts fibroblasts to produce collagen over time rather than filling at injection	Does not give shape on the day; cannot be dissolved	Swelling and tenderness as the injected fluid settles	Gradual, diffuse volume loss across the face rather than a single hollow
Skin booster	Lightly cross-linked or uncross-linked hyaluronic acid, or a polynucleotide, placed within the dermis for hydration and skin quality	Does not project, contour or replace lost volume	Small raised bumps at the injection points while they settle	Dull, dehydrated or crepey skin over adequate underlying structure
Energy-based tightening (HIFU, VF Lift – Vertical Facelift)	Heats deeper layers to provoke a collagen response in lax tissue	Does not replace lost volume or change skeletal shape	Transient redness, tenderness or swelling	Laxity rather than volume loss, the change a filler cannot address
Surgery (facelift, rhinoplasty, implants, fat grafting)	Repositions or removes tissue, reshapes the nose, or adds volume surgically	Not reversible in the way hyaluronic acid filler is; involves incisions and anaesthesia	The longest recovery of these options, set out by the operating team	Marked laxity, a nose that needs to be made smaller, or change beyond what filler can do; referred for a surgical opinion

Fillers for the face: which filler goes where?

Which filler goes where depends on what the area needs to do: project against bone, soften a hollow, or move with expression. Firmer gels and microsphere fillers suit areas that need support on bone, while soft hyaluronic acid suits thin, mobile tissue where a firm product would show or feel wrong, and where reversibility matters most.

On the cheekbone, chin and jawline, filler is placed deep on bone to restore projection, using a high-G′ hyaluronic acid or, where reversibility is not the priority, calcium hydroxylapatite or polycaprolactone. In the temples, a hollow is softened in a deep plane. For the nose bridge, calcium hydroxylapatite or polycaprolactone is usually chosen here for the support they give, with hyaluronic acid where a dissolvable option is preferred; filler can raise or straighten a bridge but cannot make a nose smaller.

The lips and tear troughs take soft, low-G′ hyaluronic acid in small increments, because these areas move constantly, sit close to the surface and benefit from a material that can be dissolved. Diffuse volume loss across the face is often better suited to a collagen biostimulator than to filler placed point by point. In every area the plan follows the examination, not a fixed number of syringes.

Which filler goes where: area by area

Area	What the filler is doing	Usual material	Plane
Cheeks	Restoring projection and support over the cheekbone	High-G′ hyaluronic acid; CaHA or PCL where reversibility is not the priority	Deep, on bone, with softer layering above where needed
Chin and jawline	Adding projection and definition to the lower face	High-G′ hyaluronic acid, CaHA or PCL	On bone
Temples	Softening a hollow that lets the tail of the brow fall	Hyaluronic acid	Deep on bone, or in the superficial fat by cannula
Nose bridge	Raising or straightening the bridge; it cannot make the nose smaller	Usually CaHA or PCL; hyaluronic acid where a dissolvable option is preferred	Deep, close to bone and cartilage, in small amounts
Lips	Volume, border definition or symmetry	Soft, low-G′ hyaluronic acid	Within the body of the lip and along the border
Tear trough	Softening a genuine hollow between the lower lid and cheek	Soft, low-G′ hyaluronic acid; CaHA and PCL generally avoided	Deep, beneath the muscle, often by cannula

Frequently Asked Questions

Are dermal fillers regulated in Singapore?+

Dermal fillers are registered with the Health Sciences Authority (HSA) as medical devices, and injecting them is a medical treatment performed by a registered medical practitioner. Regulation covers the product; it does not remove the risks of injection, which are managed by assessment, choice of material and plane, and having hyaluronidase available.

What is the difference between a dermal filler and a skin booster?+

A dermal filler is a cross-linked gel that occupies space and restores structure, such as a cheek, chin or temple. A skin booster is lightly cross-linked hyaluronic acid or a polynucleotide placed within the dermis to act on hydration and skin quality. One adds volume, the other acts on the skin itself, and neither does the job of the other.

Can dermal filler be dissolved?+

Hyaluronic acid filler can be dissolved with hyaluronidase, an enzyme that breaks the gel down so the body clears it. Calcium hydroxylapatite (Radiesse), polycaprolactone (Ellanse) and poly-L-lactic acid cannot be dissolved by enzyme and are resorbed over time. Ultrasound guidance lets the enzyme be directed at the misplaced product rather than the whole area.

What is pillow face and how does it happen?+

Pillow face is the rounded, heavy appearance that results from too much filler, usually accumulated over repeated treatments in the same zones. Each addition is layered on product still present, so the total volume rises past what the facial skeleton supports. It is corrected by dissolving the excess hyaluronic acid under ultrasound guidance and re-assessing the face from the beginning.

Does filler lift a sagging face?+

A filler adds volume; it does not lift tissue or tighten skin. Restoring a deflated cheek can improve how the midface is supported, but jowls and loose skin are laxity, a different process addressed by energy-based or thread-based methods that act on the supporting layers by a different mechanism. Filling a lax face makes it heavier, not lifted.

What is a vascular occlusion and how would I know?+

A vascular occlusion happens when filler enters or compresses an artery and blocks blood flow to the tissue it supplies. The warning signs are skin that blanches or turns dusky or mottled, pain out of proportion to the injection, and in rare cases any change in vision. It is an emergency treated with high-dose hyaluronidase and should be reported the same day.

Can I have dermal fillers if I am pregnant or breastfeeding?+

Filler treatment is deferred during pregnancy and breastfeeding. Fillers have not been studied in these groups, and the fluid shifts of pregnancy alter how the face looks in any case. Treatment is also deferred where there is an active infection at or near the site, including a cold sore, and is assessed individually in people with autoimmune or inflammatory conditions.

What determines the cost of dermal fillers in Singapore?+

Cost depends on the areas treated and how many, what the examination finds in each, the product chosen and the quantity the anatomy calls for, whether filler is used alone or with toxin or a biostimulator, and whether the plan is staged across more than one visit. Correction of previous filler is costed separately. Cost is set out at consultation.

Do dermal fillers hurt?+

Most people describe pressure and a brief sting rather than significant pain. A topical anaesthetic is applied beforehand, and most hyaluronic acid fillers contain lidocaine, a local anaesthetic that numbs the area as the product is placed. The lips are the most sensitive area and comfort there is managed accordingly.

What should I avoid after dermal filler treatment?+

Avoid pressing or massaging the treated area unless advised to, and keep make-up off the entry points until they have closed. Strenuous exercise, saunas, alcohol and facial treatments that apply heat or pressure are postponed for a short period. Dental work, vaccinations or travel planned close to the treatment date are worth mentioning beforehand. Specific aftercare is given for the areas treated.

Can filler and botulinum toxin be given at the same visit?+

Often, yes. They act on different tissues, filler on volume and botulinum toxin on muscle contraction, and both can be planned within one appointment where the assessment calls for it. Sometimes the toxin is given first and filler later, so the effect of relaxing a muscle is seen before volume is added. The sequence is decided individually.

Which type of filler is used for the nose?+

Here, nose filler is usually calcium hydroxylapatite or polycaprolactone, chosen for the support they give the bridge, with hyaluronic acid where a dissolvable option is preferred. CaHA and PCL cannot be dissolved with hyaluronidase, so placement and quantity are planned conservatively. The nose also carries a higher vascular risk than many areas, which shapes the technique and the amount used.

Is there a right age to start dermal fillers?+

No. Filler follows anatomy rather than age: a retruded chin or low nasal bridge can be addressed in younger adults, while volume loss from fat-pad deflation and bone change tends to appear later. The useful question is whether volume is genuinely missing, which the examination decides. Starting early with repeated top-ups is one of the routes to over-filling.

Medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last updated 5 October 2026 · Editorial policy