Key facts
- What HIFU reaches
- Lax skin and the platysma beneath the chin, through the 3.0 mm and 4.5 mm cartridges
- What it does not reach
- A full fat pad, the submandibular gland, a short chin, or forward head posture
- Where energy is kept away
- The thyroid, the course of the marginal mandibular nerve, and thin tissue over bone
- Who tends to suit
- A soft submental envelope that gathers when the head tilts down, with little fat on pinch
- Alternatives assessed
- Fat-directed energy, Time Freeze Laser LCLR®, VF Lift, botulinum toxin for bands, chin projection, referral
- Fee
- Set in writing after assessment; see how fees are quoted
What is actually under a double chin, and which part does HIFU reach?
A double chin is an appearance with up to six causes, and HIFU reaches one and a half of them. Focused ultrasound heats small points in lax skin and in the platysma, the thin sheet of muscle under the chin, so it addresses the loose envelope. It does not reduce the fat pad that sits above or below that muscle, shrink a prominent submandibular gland, bring forward a short chin, or correct the forward head posture that folds the neck. The double chin treatment page sets out all the causes; this page covers what HIFU does and does not do among them.
Most people have more than one cause. A lean person can carry a double chin from a short chin and a soft envelope, and a heavier person can have a full fat pad under skin that is still firm. Treating the envelope when the problem is the contents produces no visible change, which is why the examination below comes before any line is placed.
How does the assessment separate fat, skin and posture?
The assessment separates the causes by pinching, tilting and watching. Pinching the tissue under the chin shows how much of it is fat: a thick fold that persists with the head up is fat, a thin fold that gathers and creases when the chin drops is skin. Asking you to clench the jaw and grimace shows whether vertical platysmal cords appear. Pushing the lower jaw forward shows whether the fullness disappears, which points to chin or jaw position rather than to anything under the skin.
Posture is checked last and explained rather than treated. A neck that looks full only when you look down at a phone or a laptop is being folded by position, and no energy device changes that; a short neck or a low hyoid bone can make even a lean submental area read as full. Where the fullness is firm, rounded and sits under the angle of the jaw, the submandibular gland is suspected and left alone. Only when laxity is a meaningful part of the picture is HIFU planned.
“You can be lean and still have a double chin.”
Dr Sin YongOn what sits under the chin · from his Instagram explainer series
Which depths are used under the chin, and where is energy kept away?
Beneath the chin the 4.5 mm cartridge is directed at the platysma and the deeper envelope, and the 3.0 mm cartridge at the dermis, with the 1.5 mm cartridge over thinner skin towards the jawline. Which cartridge goes where follows the pinch: the 4.5 mm cartridge is used only where there is enough tissue depth for its focal point to sit in the platysma rather than against bone or into the fat of a lean neck, and the lines run along the submental area and the jawline rather than down the front of the neck.
Three structures are kept out of the field. The thyroid gland sits low in the front of the neck and is not treated over. The marginal mandibular nerve runs along the lower border of the jaw before turning up to the corner of the mouth, so lines near the jaw edge are placed with that course in mind. Thin tissue directly over the chin bone is spared at 4.5 mm. Energy is adjusted to what you feel line by line, and the HIFU page explains why line counts are not a measure of treatment.
What sits under a double chin, and whether HIFU reaches it| Component | How it is recognised | Does HIFU address it? |
|---|
| Submental fat | Thick pinch; fullness persists with the head up and jaw forward | No; fat-directed energy or Time Freeze Laser LCLR® is assessed |
| Loose skin | Thin pinch; the envelope gathers and creases when the chin drops | Yes, where tissue depth allows the cartridge |
| Platysma laxity or bands | Vertical cords on clenching; a blunted angle under the jaw | Partly; laxity yes, muscular bands answer to botulinum toxin |
| Submandibular gland | A firm, rounded fullness under the jaw angle that does not pinch | No; it is identified so it is not treated as fat |
| Short chin or jaw | Fullness that resolves when the jaw is pushed forward | No; chin projection is a structural question |
| Posture | Fullness that appears on looking down or at a screen | No; it is explained, not treated |
Who suits HIFU for a double chin, and who is better served elsewhere?
HIFU suits a double chin whose main component is a soft, loose envelope with little fat on pinch: typically someone in their late thirties onwards who has noticed the area gather and crease rather than fill out. It also suits the person who has already had fat reduced and is left with a lax envelope, once that area has settled. In both, the skin and platysma are the problem, and that is the layer focused ultrasound heats.
A full fat pad is better served by energy directed at fat, such as microwave energy that is absorbed preferentially by fat, radiofrequency contouring, or the Time Freeze Laser LCLR® protocol directed at compact submental fat together with dermal laxity. Vertical platysmal bands are muscular and answer to botulinum toxin rather than to heat. A short chin is a question of projection, assessed separately. Where the dermis and subcutaneous layer are the main issue, the VF Lift – Vertical Facelift, which uses Volnewmer monopolar radiofrequency and no focused ultrasound, may be considered instead. A heavy neck with a great deal of redundant skin is referred to a plastic surgery specialist.
What are the risks under the chin, and what determines the fee?
The risks specific to the submental area come from what lies close by. Heat near the marginal mandibular nerve can cause temporary weakness or asymmetry at the corner of the mouth, and heat placed into the fat of a lean neck can leave the area looking hollow or make the platysmal cords more visible. Bruising, tenderness over the jaw edge, a small welt and a patch of altered sensation can occur and are reviewed. Marked or one-sided swelling, a change in mouth movement or a welt that does not flatten should be reported the same day; the complication care page lists the signs that need prompt attention.
The fee follows the assessment rather than a list: the depths and zones the examination calls for, whether HIFU is planned alone or alongside a fat-directed step, botulinum toxin or chin projection, and how the plan is staged around review. Singapore's rules prevent clinics from advertising prices, so no figures appear here, and a written quote follows the consultation, as the how fees are quoted page explains.
