When an enlarged masseter is the cause of a square-looking jaw, botulinum toxin injection can relax the muscle, which may make it less bulky and the jawline look softer over the following weeks. It cannot change bone shape, results vary and are temporary, and repeat treatment is needed. Masseter treatment at Trust Dental is $650 before GST, by Dr Celeste Ng or Dr Celeste Ling.
Is It Muscle or Bone?
A square jaw can come from a large masseter muscle, the shape of the jawbone, or both. Clench your teeth and feel the angle of your jaw: if a firm bulge pops out, muscle is likely contributing. Your dentist checks this at your assessment, because injections only affect the muscle.
What to Expect: Timeline
| When | What usually happens |
|---|---|
| First few days | Little visible change; possible mild tenderness |
| Around 2 weeks | Clenching force noticeably lower; chewing tough food may feel tiring |
| Following weeks | Muscle may gradually become less bulky; jawline can look softer |
| Several months on | Effect wears off gradually as the muscle recovers; repeat if wanted |
Results vary from person to person, so we don't promise a particular change in face shape.
Masseter treatment at Trust Dental: $650 before GST ($708.50 with GST). Carried out by Dr Celeste Ng or Dr Celeste Ling, both accredited by the Singapore Dental Council for botulinum toxin injection.
See botulinum toxin injection at Trust DentalThe Dental Benefit
For many people with a large masseter, the cause is clenching or grinding. Relaxing the muscle can also ease jaw tension and reduce the force on the teeth. That's why we treat it as a dental issue first. See botulinum toxin for grinding and clenching.
Side Effects and Who Should Wait
- Tenderness or bruising at the injection sites
- Chewing tough food may feel tiring for a while
- Headache
- Not suitable during pregnancy or breastfeeding, with neuromuscular conditions such as myasthenia gravis, with infection at the site, or with a previous allergy to botulinum toxin
Aftercare
For the rest of the day, avoid massaging the jaw, lying flat for a few hours, strenuous exercise and saunas. Normal eating and work can continue.
