Masseter Botox — anti-wrinkle injections into the large chewing muscle on either side of the jaw — is used both for aesthetic jaw contouring and to reduce jaw tension. This article explains what it involves, who it may help, and what to expect, including where its limitations lie.
What Is the Masseter Muscle?
The masseter is one of the primary muscles involved in chewing. It runs along the lower jaw on both sides, from the cheekbone to the lower edge of the mandible. In some people, this muscle is larger or more developed than average — either naturally or because of habitual teeth grinding (bruxism) or jaw clenching. A pronounced masseter can give the lower face a wider, more square appearance.
Two Reasons People Seek Masseter Treatment
1. Aesthetic: Jaw Slimming and V-Shape Contouring
When botulinum toxin is injected into an overdeveloped masseter, the muscle gradually reduces in bulk over the following weeks. This can soften the lower face and create a slimmer, more tapered jawline — sometimes called a “V-shape” or masseter reduction. The effect is temporary and requires maintenance treatments to sustain.
This treatment tends to be most noticeable in people whose masseter is genuinely enlarged. If jaw width is primarily due to bone structure rather than muscle size, the effect will be more limited — something an honest consultation will tell you upfront.
2. Functional: Jaw Tension and Teeth Grinding
Some people use masseter injections to reduce jaw tension, discomfort from clenching, or the effects of bruxism — teeth grinding, often during sleep. By reducing the muscle’s activity, the treatment may help with tension-related symptoms like jaw soreness or headaches linked to clenching.
An important note: jaw pain, headaches, and clicking or locking of the jaw can be symptoms of temporomandibular joint (TMJ) disorders, which have a range of possible causes. If you’re experiencing significant jaw pain or TMJ symptoms, the appropriate first step is an assessment by a dentist or doctor — not an aesthetic treatment. Masseter injections may be one part of managing some TMJ-related symptoms, but they are not a treatment for TMJ disorders themselves, and they are not suitable for all causes of jaw pain.
What the Treatment Involves
The injector asks you to clench your teeth so they can locate and assess the masseter. A series of small injections are then placed into the muscle on each side. The appointment typically takes around 30–45 minutes. There is minimal downtime — some people experience slight tenderness or swelling at the injection sites for a day or two.
The full effect takes time. The muscle doesn’t reduce immediately — most people start to notice a change in jaw appearance and feel after 4–6 weeks, with the full result visible closer to 3 months. The effect is temporary; maintenance treatments are needed to sustain it.
Who May Be Suited to This Treatment
Masseter injections may be worth exploring if:
- You have a noticeably enlarged masseter muscle (not just broad bone structure)
- You grind your teeth or clench your jaw and are looking for symptom management alongside, or after, professional dental or medical advice
- You want a non-surgical approach to softening the lower face
A consultation is the right starting point. An experienced injector will assess your anatomy, ask about your goals, and be honest about whether the treatment is likely to make a meaningful difference in your case.
Pricing at MJ Aesthetics
At MJ Aesthetics in North York, masseter and jaw slimming treatments are priced at $6.50 per unit — the same per-unit rate as other anti-wrinkle treatments. The masseter typically requires more units than upper face treatments; the total depends on muscle size and the number of units used, which is determined at consultation.
TMJ-related jaw treatments are also available at the same per-unit rate. See the full anti-wrinkle treatment page for pricing details.
About MJ Aesthetics
Mehran Javidan is an International Medical Graduate (IMG) with approximately 20 years of hands-on experience in medical aesthetics. He is not currently registered as a physician with the College of Physicians and Surgeons of Ontario (CPSO), and all aesthetic procedures at MJ Aesthetics are performed under physician delegation in accordance with Ontario’s Regulated Health Professions Act.
MJ Aesthetics is located at 1110 Sheppard Ave E #304, North York. Book a free consultation online or call 437-556-1119.
Frequently Asked Questions
Is masseter Botox painful?
Most people find it manageable — the masseter muscle is thick, and the injections are relatively quick. Some find the jaw area slightly more sensitive than the forehead, but discomfort is typically brief.
How long does masseter Botox last?
Results typically last 3–6 months, though this varies. Some people find the effect lasts longer after several treatments, as the muscle gradually reduces in size over time. Individual results vary.
Will it affect my ability to chew?
Done correctly with appropriate dosing, masseter treatment should not significantly impair chewing. You may notice the muscle feels slightly weaker for a few weeks, but eating is generally not affected. This is something to discuss with your injector at consultation.
Should I see a doctor before having this treatment for jaw pain?
Yes — if jaw pain, headaches, or jaw dysfunction are significant concerns, an assessment by a dentist or doctor is the appropriate first step. Masseter injections may complement other management approaches but are not a standalone treatment for TMJ disorders.