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Glossary: the words we use, explained plainly.

Aesthetic and dermatology terms as they are actually used in the clinic, including the Malaysian regulatory vocabulary nobody explains. Written for patients, not for other doctors.

Injectables, what they are

Dermal filler

A gel, almost always hyaluronic acid, placed to restore volume or refine contour. It works by occupying space, which is why it is the right answer for a hollow and the wrong answer for pigmentation. Fillers used here are registered with Malaysia's Medical Device Authority, and unusually low quotes are worth questioning: counterfeit product is a real trade in this region.

Dermal fillers at AOKLINIK

Biostimulator

An injectable that provokes your own collagen rather than filling space directly. Results arrive over months rather than at the appointment, which is the whole point and also the reason patients expecting an immediate change are sometimes disappointed. Poly-L-lactic acid and calcium hydroxylapatite are the two in common use.

Biostimulators explained

Cross-linked and non-cross-linked hyaluronic acid

Cross-linking binds hyaluronic acid chains together so the gel holds a shape and lasts. Non-cross-linked hyaluronic acid does not hold shape and is used to improve hydration and skin quality instead. The distinction matters because the two are sold under similar names and do entirely different jobs.

Skin boosters guide

CaHA, calcium hydroxylapatite

Microspheres suspended in a gel carrier. Used at standard concentration it lifts and contours; diluted, it behaves as a collagen stimulator across a broader area. It is not reversible with hyaluronidase, which is the main practical difference from a hyaluronic acid filler and the reason placement matters more.

Hyperdilution with CaHA

PLLA, poly-L-lactic acid

A biostimulator that works by controlled inflammation, prompting fibroblasts to lay down new collagen over three to six months. Delivered in a series rather than a single session. It suits gradual, structural change in the midface and lower face, and it is a poor choice for anyone wanting to look different by the weekend.

Sculptra and Radiesse compared

Hyperdilution

Diluting a biostimulator well beyond its standard concentration so it can be spread across a wide area for skin quality rather than volume. Common on the neck, decolletage and lateral face. The technique changes what the product does, so the dilution ratio and the injection plane are the decision, not the brand.

Hyperdilution explained

Botulinum toxin type A

A purified protein that temporarily reduces muscle contraction, softening the lines that repeated expression creates. It is a prescription medicine, registered in Malaysia by the National Pharmaceutical Regulatory Agency rather than as a medical device, and supplied only by a registered practitioner. The products available are not interchangeable unit for unit. Effect appears over three to ten days and fades over three to four months.

Botulinum toxin, what changed

Unit

The measure of botulinum toxin activity. Units are specific to each product and cannot be compared directly, so a price quoted per unit means nothing without knowing which product it refers to. This is the most common source of confusion when patients compare quotes between clinics.

Seven questions on botulinum

Diffusion

How far botulinum toxin spreads from the point of injection. Greater diffusion can be useful across a broad forehead and unhelpful near the eyelid or mouth, where it causes unintended weakness. Managing it is a matter of dilution, dose and placement rather than a property of the product alone.

Botulinum toxin, what changed

Neocollagenesis

The formation of new collagen in response to a controlled stimulus, whether injectable, ultrasound or laser. It is slow by nature. Any treatment claiming to build collagen and show the result the same week is describing swelling, not collagen.

Fillers versus biostimulators

How an injectable gel behaves

Rheology

The study of how a gel flows and deforms. It is the honest basis for choosing an injectable, because it describes what the product will actually do under skin rather than what the box says. Two fillers with identical hyaluronic acid concentration can behave completely differently.

Tear trough guide

Elastic modulus, G prime

How firmly a gel resists deformation. High G prime holds structure and suits deep placement on bone; low G prime integrates softly and suits thin, mobile skin. Using a high G prime product under the eye is a common cause of a visible ridge.

Tear trough guide

Cohesivity

How strongly a gel holds together rather than spreading after placement. Cohesive products stay where they were put, which matters most in areas with movement and thin skin. It is measured separately from firmness, and the two are frequently confused.

Tear trough guide

Hydrophilicity

How much water a gel draws in after placement. Useful in a cheek, unhelpful under an eye. A highly hydrophilic product placed where lymphatic drainage is sluggish produces puffiness weeks after the procedural swelling has settled, and that puffiness can last a long time.

Tear trough guide

Cross-linking

The chemical bonding that turns free hyaluronic acid into a gel with structure and duration. Degree and pattern of cross-linking drive firmness, longevity and how the product integrates. It is the single biggest reason two hyaluronic acid fillers are not substitutes for each other.

Skin boosters guide

Anatomy the result depends on

Tear trough ligament

A true osteocutaneous ligament running from the inner corner of the eye diagonally downward, anchoring skin directly to the maxillary bone. It creates a fixed groove between two tissue planes of very different thickness. Filling the hollow without respecting it produces the shelf-like look you see on people who have obviously had something done.

Tear trough guide

Orbicularis retaining ligament

The lateral continuation of the tear trough ligament, tethering the eyelid tissue to the orbital rim. Together they form the boundary that gives the under-eye its shadow. Understanding where it sits is the difference between softening a groove and creating a new one.

Tear trough guide

Supraperiosteal plane

The layer immediately above the bone and beneath the muscle. Placing product here, deep and on bone, is standard practice in high-risk regions because it keeps the gel away from superficial vessels and away from translucent skin where it would show.

Tear trough guide

Periorbital region

The area around the eye. Skin here is around half a millimetre thick, the thinnest on the body, with almost no subcutaneous fat. Every technical decision, product, plane, volume and instrument, is stricter here than anywhere else on the face.

Tear trough guide

Lid-cheek junction

Where the eyelid tissue meets the cheek. Restoring support at this junction frequently improves the under-eye shadow before anything is placed in the trough itself, which is why an experienced injector treats the foundation before the hollow.

Tear trough guide

Midface

The region between the lower eyelid and the mouth, including the anterior cheek. Deflation here is often the cause of complaints attributed to the eyes or the nasolabial folds. Treating it first changes what the rest of the face needs.

Aesthetic medicine

Fat pad prolapse

True herniation of orbital fat, producing a bulge with a groove beneath it. This is a surgical problem. Filling the groove to camouflage the bulge is a compromise, and often a poor one, which is why assessment matters more than product choice.

Tear trough guide

SMAS

The superficial musculoaponeurotic system, a fibrous layer connecting facial muscles to skin. It is the layer surgical facelifts address and the layer focused ultrasound targets non-surgically, which is why the two are sometimes compared.

Aesthetic medicine

Glabella

The area between the eyebrows. Along with the nose and the under-eye, it is one of the highest-risk zones on the face for filler-associated vascular events, because of its arterial supply and its connection to the ophthalmic circulation.

Tear trough guide

Safety, complications and reversal

Vascular occlusion

Filler entering or compressing an artery, interrupting blood supply. In the periorbital region, glabella and nose, product can travel back into the ophthalmic circulation and cause sudden, usually permanent vision loss. It is rare and it is not theoretical. Ask any clinic whether they stock hyaluronidase and what their written protocol is.

Tear trough guide

Hyaluronidase

An enzyme that dissolves hyaluronic acid, used both to correct an unsatisfactory result and as emergency treatment for vascular occlusion. Its availability on the premises is a reasonable question to ask before treatment, and it is one reason permanent fillers are not used in high-risk areas.

Tear trough guide

Tyndall effect

The blue-grey cast that appears when clear gel sits too superficially beneath translucent skin, scattering shorter blue wavelengths back at the viewer. It is a placement error rather than a product fault, it can persist for a long time, and it is correctable with hyaluronidase.

Tear trough guide

Malar oedema

Persistent swelling over the cheekbone where lymphatic drainage is already marginal. Water-attracting product placed in this region can make it dramatically worse for months or years. Morning puffiness before treatment is a reason to decline, not a reason to inject more.

Tear trough guide

Festoon

A hammock of lax skin and swelling sitting below the lower eyelid. Festoons do not respond to filler and are reliably worsened by it. Recognising them at assessment is one of the more useful things a doctor can do for a patient asking for under-eye treatment.

Tear trough guide

Delayed inflammatory nodule

A firm, tender lump appearing weeks or months after injection, sometimes triggered by illness or vaccination. It is uncommon, it is usually manageable, and it is one of the recognised risks that should be discussed before treatment rather than after.

Aesthetic medicine

Cannula and needle

A cannula is blunt-tipped and introduced through a single entry point; a needle is sharp. A cannula is significantly less likely to enter a vessel, which is why it is preferred in higher-risk regions. Neither instrument removes risk on its own.

Tear trough guide

Biofilm

A community of bacteria that can establish on an implanted material and remain dormant, sometimes becoming symptomatic long after the procedure. It is one reason sterile technique and product provenance matter more than the price on the quote.

Aesthetic medicine

Energy devices and lasers

Micro-focused ultrasound, HIFU

Ultrasound energy focused at defined depths to create small zones of controlled thermal injury, prompting collagen contraction and remodelling. Used for lifting at the lower face and neck. It is never delivered inside the bony orbital rim, and eye shielding is used near the eye.

Aesthetic medicine

Er:YAG laser

A 2940nm laser strongly absorbed by water. Delivered ablatively it resurfaces; delivered as a long pulse train in non-ablative mode it heats the dermis without breaking the surface, which is the setting used around the eye where downtime is unacceptable.

Aesthetic medicine

Nd:YAG laser

A 1064nm laser that reaches deeper and is comparatively safe in darker skin, which matters here: most of our patients are Fitzpatrick III to V. Used for vascular targets, pigment and gentle dermal heating.

Dermatology care

Pico laser

A laser delivering energy in picosecond pulses, shattering pigment with a photoacoustic effect rather than heat. Lower thermal load means lower risk of post-inflammatory hyperpigmentation, which is the main reason it is favoured for pigment work in Asian skin.

Melasma in darker skin

Q-switched laser

The nanosecond-pulse predecessor to picosecond systems, still effective for many pigment targets. The distinction between the two is pulse duration, and in darker skin that difference changes the risk profile rather than only the speed of clearance.

Dermatology care

Fractional resurfacing

Treating a fraction of the skin surface in columns, leaving untreated skin between them to speed healing. It trades intensity per session for safety and downtime, and in Fitzpatrick IV and V skin that trade is usually worth making.

Acne scars in Asian skin

Radiofrequency

Electrical energy converted to heat within the dermis to stimulate collagen. Depth is controlled by device design rather than by pigment absorption, which makes it comparatively colour-blind and therefore useful across a wide range of skin tones.

Aesthetic medicine

Thread lift

Absorbable sutures placed under the skin to reposition tissue and provoke collagen along their path. Effect is modest compared with surgery and depends heavily on patient selection. It suits mild laxity with good skin quality, and disappoints where there is significant descent.

Choosing a thread lift

PDO and PCL threads

Polydioxanone and polycaprolactone, the two common absorbable thread materials. PDO absorbs over months, PCL considerably more slowly with a longer collagen response. The material affects duration and the type of lift achievable.

Choosing a thread lift

Skin conditions and Asian skin

Fitzpatrick skin type

A six-point scale describing how skin responds to ultraviolet light. Most patients in Malaysia fall between III and V, which changes almost every treatment decision: laser settings, energy levels, the risk of post-inflammatory pigmentation and how cautiously a course should be escalated.

Dermatology care

Melasma

A chronic, relapsing pigmentation pattern driven by hormones, heat and light, common in Asian skin and rarely cured outright. It is managed rather than removed, and aggressive laser treatment frequently makes it worse. Control comes before clearance.

Melasma in darker skin

Post-inflammatory hyperpigmentation

Darkening that follows inflammation, whether from acne, a procedure or an injury. It is far more common and more persistent in Fitzpatrick III to V skin, and it is the single biggest reason treatment intensity is kept conservative in this population.

Acne scars in Asian skin

Visible light photoprotection

Protection against the visible part of the spectrum, not just ultraviolet. Visible light worsens melasma in darker skin, and most conventional sunscreens do little against it. Tinted formulations containing iron oxide are the practical answer.

Sunscreen and visible light

Tranexamic acid

A medication used in melasma management, topically or under supervision by other routes. It works on the vascular and inflammatory drivers of pigmentation rather than on melanin alone, which is why it is often combined with other measures rather than used by itself.

Melasma in darker skin

Atrophic scarring

Depressed acne scarring, usually described in three shapes. Icepick scars are narrow and deep, boxcar scars have defined edges, rolling scars are broad and tethered from beneath. Each responds to a different technique, which is why one laser rarely fixes an entire face.

Acne scars in Asian skin

Subcision

Releasing the fibrous tethers that hold a rolling scar down, using a needle or cannula passed beneath it. It addresses the mechanical cause rather than resurfacing the top, and it is frequently the step that makes subsequent laser work worthwhile.

Acne scars in Asian skin

TCA CROSS

Chemical reconstruction of skin scars: a high concentration of trichloroacetic acid applied precisely into an icepick scar to prompt it to fill from below. Focal and technique-dependent, and unforgiving of imprecision in darker skin.

Acne scars in Asian skin

Keloid

Scar tissue that grows beyond the boundary of the original wound. Risk is higher in darker skin and there is a familial tendency, which is why it is asked about before any procedure that breaks the skin.

Dermatology care

Erythema

Redness from dilated superficial blood vessels or inflammation. Transient erythema after a procedure is expected; erythema persisting well beyond the stated recovery window is worth reviewing rather than waiting out.

Dermatology care

Malaysian regulatory vocabulary

MDA registration

The Medical Device Authority registers medical devices for use in Malaysia under Act 737. Dermal fillers and biostimulators fall into this category. Botulinum toxin does not: it is a medicine, and sits under a different authority. Registration is a legitimate question to ask about any product proposed for you, and a clinic should be able to answer it without hesitation.

About AOKLINIK

NPRA registration

The National Pharmaceutical Regulatory Agency registers medicines for use in Malaysia, botulinum toxin among them. Registered products carry a MAL number. It is a separate system from device registration, and the distinction matters in practice: a medicine must be prescribed by a registered practitioner, and there are limits on how it may be advertised to the public.

About AOKLINIK

LCP credential

Accreditation under the Letter of Credentialling and Privileging framework, which permits a registered medical practitioner to perform specified aesthetic procedures in Malaysia. It is issued to the individual doctor for named procedures, not to the clinic in general.

Our doctors

KKLIU and the Medicine Advertisements Board

The Medicine Advertisements Board, Lembaga Iklan Ubat, reviews healthcare advertising in Malaysia and issues a KKLIU approval number for approved material. It is why medical clinic advertising here is more restrained than you may be used to elsewhere, and why prescription medicines are not named in public-facing material.

About AOKLINIK

Off-label use

Using a registered product outside the specific indication it was registered for. It is lawful, common in aesthetic medicine and often well evidenced, but it should be stated openly during consent rather than discovered afterwards.

About AOKLINIK

These definitions are general educational information, not medical advice, a diagnosis or an offer of treatment. Suitability and outcomes are determined individually at consultation and vary between people. Longevity and preventive health terminology is covered separately by Hayat Longevity.

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