Masseter Botox
Masseter Botox slims the lower face and quiets jaw clenching at the same time. By relaxing the chewing muscle that runs along the side of the jaw, the treatment narrows a square or wide jawline and relieves the grinding, tension headaches, and TMJ pain that often go with a strong masseter.
The masseter is the thick chewing muscle that sits on the side of the jaw, between the cheekbone and the angle of the jawline. When it is overworked, from genetics, from chronic clenching, or from grinding teeth at night, it becomes hypertrophic, meaning visibly bulky. The result is a wider, more square lower face, a fuller jaw angle, and often morning soreness, tension headaches, and worn or sensitive teeth.
Masseter Botox, also called jaw slimming or masseter reduction, uses small-volume injections of botulinum toxin type A, Botox, Dysport, Xeomin, or Daxxify, placed directly into the muscle. Over the following weeks, the muscle contracts less forcefully, gradually atrophies, and the lower face narrows. The cosmetic slimming and the functional relief, less clenching, less grinding, less jaw fatigue, usually arrive together.
Patients come in for one of two reasons, sometimes both. The cosmetic patient wants a softer, more oval lower face; less width at the jaw angle; a more refined profile from the side. The functional patient wants relief from bruxism (teeth grinding), morning jaw stiffness, headaches that start at the temple, or TMJ symptoms. The treatment is the same. The dosing is calibrated to the goal.
Dosing in the masseter is larger per side than dosing in the forehead, because the muscle is large and deep. This matters for product choice. Daxxify, with its approximately six-month duration, can be efficient in the masseter because fewer visits per year are needed. Botox and Dysport are workhorses here and very well studied. Xeomin is a good choice for patients who have built reduced response to other formulations.
As a board-certified oculofacial plastic surgeon in Los Angeles, Dr. Boxrud personally evaluates and personally injects every patient. The masseter is palpated while you clench, the muscle is mapped, and dosing is matched to its actual size and your goal, not to a default unit count. Patients across Los Angeles, Santa Monica, and Beverly Hills see her for the version of this treatment that is calibrated, conservative, and adjusted at every visit.
- Visit
- 15 to 20 minutes.
- Anesthesia
- None required; topical numbing available.
- Onset
- Functional relief (less clenching) within 1 to 2 weeks. Visible slimming at 4 to 6 weeks, continuing for 2 to 3 months.
- Duration
- 4 to 6 months for Botox, Dysport, Xeomin. Up to 6 months or longer for Daxxify.
- Products available
- Botox, Dysport, Xeomin, Daxxify.
- Downtime
- None. Light bruising possible; chew softer foods for 24 hours.
- Maintenance
- Most patients return every 4 to 6 months; some can extend after several cycles.
How long until I see jaw slimming?
Functional relief, less clenching and less morning soreness, often begins within 1 to 2 weeks. Visible slimming of the lower face takes longer because the muscle has to atrophy. Most patients see meaningful change at 4 to 6 weeks, with continued slimming through 2 to 3 months.
How long do results last?
A single treatment typically lasts 4 to 6 months for Botox, Dysport, and Xeomin; Daxxify can extend that. After several treatment cycles, many patients find the muscle stays smaller for longer between visits.
Will it change how I chew or smile?
No, when dosed correctly. The masseter is one of several chewing muscles and is targeted precisely. Smiling, talking, and normal chewing are unaffected. Very tough foods may feel slightly more effort during the first weeks of treatment.
Does masseter Botox help TMJ?
For many patients, yes. By reducing the contraction force of the masseter, the treatment relieves the muscular component of TMJ pain, the clenching, the tension, the radiating headaches. It is not a treatment for structural joint disease, which is evaluated separately.
Which is better for the masseter, Botox or Dysport?
Both work well. Dysport has a slightly faster onset and a broader diffusion pattern; Botox is the most studied. Daxxify is often chosen here for its longer duration, since the masseter requires larger doses. Dr. Boxrud will recommend the right product based on your goals and prior response.
Is masseter Botox covered by insurance?
Cosmetic jaw slimming is generally not covered. Treatment for documented bruxism or TMJ-related muscle pain may be reimbursable in some plans. The office can discuss specifics at consultation.
Will it sag my face?
Not when dosed and placed correctly. Concerns about “face sagging” from masseter Botox come from over-dosing or off-target placement. Conservative, anatomic dosing, refined over multiple visits, is the way to avoid this.