Face slimming in Singapore starts with finding what makes the lower face wide: an enlarged masseter, buccal or subcutaneous fat, skin laxity or the jaw bone. Botulinum toxin narrows the face only where muscle is the cause; fat, laxity and a short chin need other approaches, and buccal fat removal is surgery, referred to a plastic surgery specialist.
- What decides the plan
- The cause of width: masseter muscle, buccal or subcutaneous fat, skin laxity or bone
- Masseter botulinum toxin
- Relaxes an enlarged chewing muscle so it gradually reduces in bulk; the effect is temporary
- Buccal fat removal
- Surgery through the inside of the mouth; referred to a plastic surgery specialist
- Filler contouring
- Chin and jawline structure that changes how the face tapers; it does not reduce width
- Not changed by injection
- The width of the jaw bone
- First step
- Clench test and pinch test at assessment with Dr Sin Yong
What Is Masseter BTX?
Masseter BTX involves the injection of BTX into the masseter muscles — the large jaw muscles on either side of the face. By reducing the contractile activity of the masseter, BTX causes the muscle to reduce in bulk gradually over the following weeks, which narrows the lower face where muscle is the cause of width.
BTX Dosing for Jaw Slimming
Dr Sin Yong's dose for jaw slimming is set per side at consultation, calibrated to the individual patient's masseter mass and expression strength. Potency units are specific to each formulation's own assay and are not directly comparable to units of other BTX products. The muscle relaxes first and reduces in bulk gradually over the following weeks.
“Patients with wide jaw bones will not achieve full width reduction from BTX alone.”
Dr Sin YongOn who masseter treatment suits
How Many Sessions Are Needed?
The response to a first treatment is reviewed before a repeat is planned. Repeat timing is not fixed in advance. As the masseter atrophies progressively with repeated treatment, the interval between sessions extends. The interval is set individually at review.
Face Slimming Beyond the Masseter
For patients where masseter reduction alone is insufficient: chin filler adds vertical length and reduces relative width; jawline filler creates a more angular jaw that reads as narrower; the lipo-modelling arm of Time Freeze Laser LCLR® is directed at compact fat along the jowl and under the chin.
Who Is a Good Candidate?
Masseter BTX suits faces where apparent facial width is primarily due to muscle bulk rather than bone structure. Patients with wide jaw bones will not achieve full width reduction from BTX alone. Dr Sin Yong assesses the primary cause of facial width at consultation.
Ready to Book a Consultation?
All treatments performed personally by Dr Sin Yong at Orchard Road, Singapore.
WhatsApp +65 8023 7170How Dr Sin Yong approaches face slimming
Dr Sin Yong begins with the cause rather than the request. At every consultation he works through the four possible sources of lower-face width, masseter muscle, buccal fat, skin laxity and the jaw bone, using the clench test at the angle of the jaw, a pinch test for the softer fat nearer the surface, and a profile view of the chin.
Where the masseter is responsible, the muscle is mapped with the jaw clenched and botulinum toxin is placed with a few small injections into its lower part on each side. He uses a formulation whose potency units are specific to its own assay, so unit figures quoted for other products are not comparable. Whether and when to repeat is decided at review rather than in advance.
For round faces he plans frame-first: defining the jawline, chin and cheek structure, reducing the masseter only where muscle contributes, and contouring subcutaneous fullness, rather than removing the buccal reserve. Where buccal fat is genuinely the main cause and surgery is a considered choice, he refers to a plastic surgery specialist.
Masseter botox vs buccal fat: which is making the face wide?
The quickest way to tell masseter from buccal fat is where the width sits and whether it changes when you clench. The masseter lies at the angle of the jaw, just in front of and below the ear, and firms and bulges when the teeth are clenched. Buccal fat sits higher and further forward in the cheek, and clenching does not change it.
That distinction decides the treatment. Botulinum toxin acts on muscle: it relaxes an enlarged masseter so the angle of the jaw narrows over the following weeks, and it does nothing for fat. Buccal fat lies deep inside its own capsule, where neither injections nor energy devices reach it; removing it is surgery, and patients for whom it is a considered choice are referred to a plastic surgery specialist.
Many faces have more than one contributor. A pinch test separates the softer subcutaneous fat near the surface from deep fullness, skin laxity can blur the jawline without adding width, and a short chin can make a modest jaw look square. Because the buccal pad deflates with age and does not regenerate once removed, all four causes are assessed before any decision to reduce it.
| Option | What it changes | What it cannot change | Typical recovery | Who it tends to suit |
|---|---|---|---|---|
| Masseter botulinum toxin | Relaxes an enlarged masseter so it reduces in bulk over the following weeks, narrowing the angle of the jaw | Fat, skin laxity, chin projection or the width of the jaw bone | Small injection marks or a bruise; firm food may feel harder to chew for a while | A wide jaw angle that bulges and firms on clenching, often with clenching or grinding |
| Buccal fat removal (surgical; referred to a plastic surgery specialist) | Removes part of the deep buccal fat pad through an incision inside the mouth | Masseter bulk, subcutaneous fat, laxity or bone; removed fat does not regenerate | Surgical recovery and aftercare set by the operating team | Fullness confirmed to be buccal, where surgery is a considered choice after the surgical team's own examination |
| Non-surgical options for buccal and lower-face fullness | Energy-based contouring of the pinchable subcutaneous fat, such as the lipo-modelling arm of Time Freeze Laser LCLR®, with definition of the jawline, chin and cheek structure around the fullness | Reach the deep buccal fat pad, which sits inside its own capsule | Depends on the components chosen; usually transient redness, swelling or bruising | A round lower face where the fullness is subcutaneous, or where a frame-first plan is preferred to removal |
| Chin and jawline filler contouring | Adds chin length and projection and defines the jawline, which changes how the face tapers towards a V shape | Narrow the jaw angle or reduce fat | Possible swelling and bruising that settle | A short or set-back chin, or a jawline that lacks definition |
- Ozempic Face: Volume Loss After Weight Loss — “Ozempic face” in Singapore: why rapid weight loss hollows the face, and how post-weight-loss volume is assessed and res…
- Pillow Face: How It Happens & Correction — Pillow face rarely arrives in one visit. How faces become overfilled gradually, and how correction is sequenced, by Dr S…
- Jaw Clenching & Face Shape: The Masseter — Masseter jaw clenching and face shape: why a wider jaw is often a stronger muscle, not weight — and how to check. Dr Sin…
- Botulinum toxin for masseter hypertrophy — Cochrane Database of Systematic Reviews (Fedorowicz Z et al.), 2013.
- Botulinum toxin type A injections for masticatory muscles hypertrophy: a systematic review — Journal of Cranio-Maxillo-Facial Surgery (Rauso R et al.), 2022.
- Efficacy of botulinum toxin for masseter muscle hypertrophy: a systematic review and meta-analysis — Journal of Plastic, Reconstructive & Aesthetic Surgery (Machado GF et al.), 2026.
- A review of the gross anatomy, functions, pathology, and clinical uses of the buccal fat pad — Surgical and Radiologic Anatomy (Yousuf S et al.), 2010.
Medically reviewed by Dr Sin Yong · Updated 7 October 2026
Frequently Asked Questions
Masseter BTX is a widely used non-surgical face slimming treatment. Combined with chin filler, a V-shape face can be refined. For fat-driven lower face heaviness, the lipo-modelling arm of Time Freeze Laser LCLR® is assessed separately.
Visible jaw slimming usually needs repeat treatments spaced months apart, planned individually. The masseter progressively reduces in bulk with each session.
Mild changes in bite strength may occur for 2–4 weeks as the masseter adapts. Normal eating is maintained throughout treatment.
With sustained treatment, masseter reduction becomes progressively more sustained. Stopping treatment allows the muscle to gradually regain bulk over 6–12 months.
Non-surgical options act on parts of it, depending on what makes the lower face wide. A V shape reads from the width at the jaw angle, the length and projection of the chin, and the line of the jaw between them. Botulinum toxin addresses an enlarged masseter, chin filler adds projection and length, and lifting addresses laxity; the width of the jaw bone is not changed by injection.