Botox injections to the masseter muscles are used for both medical and aesthetic purposes, including jaw slimming, teeth grinding (bruxism), and jaw tension or pain. At Dr Kynan Aesthetics on the Gold Coast, masseter Botox is performed by a medical doctor using a conservative, anatomy-focused approach to maximise benefit while minimising risk.

Why Treat the Masseter Muscles with Botox?

The masseter muscles are powerful chewing muscles located at the angle of the jaw. In some individuals, these muscles become overactive or hypertrophied, leading to functional symptoms or facial widening.

Common reasons patients seek masseter Botox include:

• Masseter hypertrophy causing a square or bulky jawline

• Teeth grinding or clenching (bruxism), particularly at night

• Jaw tension or facial pain, often stress-related

• Headaches associated with jaw overuse

Why Does Masseter Hypertrophy Occur?

Masseter enlargement and overactivity may result from:

• Genetic predisposition (naturally stronger jaw musculature)

• Chronic clenching or grinding

• Stress and anxiety

• Stimulant use (including caffeine and certain medications)

• Recreational drug use (e.g. MDMA), which increases jaw activity

In patients with bruxism, prolonged overuse can lead to tooth wear, fractures, jaw pain, and temporomandibular joint (TMJ) strain.

Benefits of Masseter Botox

Botox works by reducing excessive muscle contraction. Benefits may include:

• Reduction in jaw clenching and grinding

• Decreased jaw pain and tension

• Reduced tooth damage over time

• Slimming of the lower face in patients with hypertrophy

• Improved facial balance and contour

Importantly, Botox does not stop chewing or speaking—it selectively weakens excessive force.

Risks and Considerations

Masseter Botox is an advanced treatment that requires precise anatomical knowledge. Potential risks include:

• Temporary chewing fatigue

• Jaw weakness when eating hard foods

• Facial asymmetry

• Asymmetrical smile, particularly if toxin diffuses into nearby muscles such as the risorius

• Rare changes in bite sensation

These risks are higher with excessive dosing or overly superior injection placement.

Dr Kynan’s Conservative Injection Approach

To reduce the risk of smile asymmetry and unintended muscle involvement, Dr Kynan preferentially injects the lower portion of the masseter muscle, well away from the risorius and smile elevator muscles. This conservative placement strategy maintains facial expression while still achieving therapeutic effect.

Dosage and Duration

Typical dosing varies based on muscle size, sex, and clinical indication:

• Approximately 15–50 units per side

• Higher doses are usually required for severe bruxism or marked hypertrophy

Results typically last 3–6 months, with repeated treatments often leading to longer-lasting muscle reduction over time.

What to Expect After Treatment

• Initial effects begin at 5–7 days

• Peak effect is seen at 3–4 weeks

• Gradual reduction in jaw bulk and tension occurs over weeks

Because larger volumes of Botox are used in this area, it is particularly important to:

• Avoid rubbing or applying pressure to the jaw for at least 4 hours

• Avoid heavy chewing or gum during the first day

• Follow all post-treatment instructions carefully

Doctor-Led Masseter Botox on the Gold Coast

The masseter region is functionally and aesthetically complex. Treatment should be performed by a practitioner with detailed knowledge of facial anatomy and neuromuscular balance. At Dr Kynan Aesthetics, all masseter Botox treatments are performed by a medical doctor, ensuring safety, precision, and natural results.

If you are considering masseter Botox on the Gold Coast, a personalised consultation will determine whether this treatment is appropriate for your symptoms and goals.

For Injectors: Masseter Neuromodulator Technique — Depth, Mapping, and Safety

Masseter neuromodulator treatment carries a high functional risk profile if anatomical boundaries are poorly respected. At Dr Kynan Aesthetics (Mermaid Waters, Gold Coast), technique selection prioritises smile preservation, predictable diffusion, and avoidance of adjacent mimetic musculature.

Choosing the Correct Working Line

A commonly taught method is to draw a line from the inferior tragus to the lateral oral commissure. Dr Kynan does not recommend this approach.

This line frequently lies too superior on the masseter, encroaching upon the inferior fibres of the risorius muscle. In patients with anatomical variation—particularly those with a more inferiorly positioned risorius—this creates a high-risk injection zone.

A superficial or misdirected injection in this region can result in:

• Asymmetrical smile

• Reduced oral commissure excursion

• Patient dissatisfaction that is slow to resolve

Preferred Safety Line

Instead, Dr Kynan advocates drawing a line from a point midway between the inferior tragus and the superior lobe to the mental crease. This line more accurately reflects the safe superior boundary of the masseter muscle and significantly reduces the likelihood of risorius involvement.

This line should be drawn carefully and respected throughout the procedure.

Muscle Mapping and Landmark Identification

With the patient clenching firmly:

1. Palpate and mark the anterior border of the masseter

2. Palpate and mark the posterior border

3. Confirm bulk and symmetry in both relaxed and clenched states

Accurate marking is essential. Anatomical variation is common, and visual estimation alone is insufficient.

Injection Point Distribution

Dr Kynan uses a five-point injection pattern, distributing the total toxin dose evenly:

• Two superior points, placed:

• Approximately 1 cm inferior to the safety line

• Within the upper third of the masseter belly

• Two inferior points, placed:

• Approximately 1 cm superior to the inferior margin of the masseter

• One central point, located midway between the superior and inferior points

This configuration ensures even muscle weakening while avoiding excessive diffusion into adjacent musculature.

Injection Depth

Depth control is critical.

• A 30-gauge insulin needle is used

• Advance until periosteal contact is felt

• Withdraw 1–3 mm prior to injection, depending on patient anatomy

This technique deposits toxin into the deep belly of the masseter, reducing superficial spread toward facial expression muscles.

In patients with marked masseter hypertrophy, periosteal contact may be difficult to appreciate. In these cases, depth should still favour deep intramuscular placement rather than superficial injection.

Documentation and Audit

All markings should be:

• Carefully drawn

• Photographed

• Stored for future reference and comparison

This allows refinement of technique over time and supports consistent outcomes, particularly in high-dose bruxism patients.

Clinical Philosophy

Masseter Botox should be approached as a functional neuromuscular treatment, not simply a volumetric aesthetic procedure. Conservative mapping, deep placement, and equal dose distribution minimise complications while delivering reliable results.

This anatomy-led approach underpins Dr Kynan’s masseter treatments for patients undergoing doctor-led Botox in Mermaid Waters and across the Gold Coast.

Masseters