Masseter Botox in Mersin: A Guide to Jaw Slimming, Teeth Clenching and Bruxism

Masseter Botox is a botulinum toxin injection into the chewing muscle (masseter) at the corner of the jaw; as the muscle's volume gradually decreases the lower face can slim down, and jaw tension and headaches linked to teeth clenching and grinding (bruxism) may ease as well. People in Mersin who are considering masseter Botox usually ask: who is it suitable for, when does it work, how long does it last, does it help with teeth clenching? Below we summarise the information on our treatment page and what scientific studies show, together with their limits.

How Does Masseter Botox Slim the Lower Face?

Masseter Botox temporarily relaxes the chewing muscle; as the muscle's volume decreases over time, the lower face slims and gains a softer, more oval contour. The masseter is a strong muscle at the corner of the jaw that works when you chew; when it is prominent or thick (masseter muscle hypertrophy), it can widen the lower face (a review of 40 articles: Kundu et al., 2022).

A 2026 meta-analysis pooling 5 randomised, placebo-controlled trials (536 participants) reports that, compared with placebo, botulinum toxin reduced masseter prominence and muscle thickness in the short term; because the differences between trials were large, the size of the reduction should be interpreted with caution, and the optimal dose and protocol have not yet been defined (Machado et al., 2026).

A Wide Lower Face Is Not Always Muscle: Who Is It Suitable For?

Masseter Botox is particularly suitable for people with a broad or angular jawline and for those who clench their teeth at night, but a wide lower face is not always caused by the muscle. Muscle, bone structure, fat tissue and skin laxity may play a role separately or together; which of them predominates is assessed at the examination, and if your concern is not within the scope of Botox, it is not recommended.

When the chewing muscle is prominent, jawline filler on its own may not deliver the definition expected; a holistic plan combined with Botox can produce a more balanced profile. When jawline filler is planned in Mersin, this distinction is clarified with a facial assessment; for the options see our filler page. For the details of jawline and chin filler, see our guide to jawline and chin filler.

How Masseter Botox Is Done, Step by Step

Masseter Botox is a short injection procedure planned at an examination; the injections are completed in a few minutes, Botox treatment usually takes 15–20 minutes and no anaesthesia is needed. The steps are as follows:

1. 1Examination and plan: Your facial anatomy, expectations, medical history and medications are assessed and the dose is planned individually. Be sure to mention any teeth clenching or grinding.
2. 2Injection: It is given into the masseter muscle with fine needles. One review stresses that there are no standard guidelines, that the injection points should lie within the boundaries of the muscle and that the number of units and the technique must be individualised (Kundu et al., 2022).
3. 3Aftercare: It is recommended not to lie down for the first 4 hours, not to massage or press the area and to avoid intense exercise and excessive heat (sauna, steam bath) on the same day; mild redness or small bruising can occur. Small corrections are made at the follow-up visit if needed.

When Does It Start Working and How Long Does It Last?

With masseter Botox the effect becomes noticeable within 15–20 days; to maintain the slimming effect, a repeat every 3–6 months is generally recommended, and as sessions are repeated the slimming effect often becomes longer-lasting. The durations reported in studies can look different: the reduction in muscle volume progresses over weeks to months, and the studies differ widely in dose, participant characteristics and the extent of hypertrophy (Kundu et al., 2022). The table separates which figure comes from where:

What Does the Evidence Say About Teeth Clenching (Bruxism)?

Studies show that masseter Botox can reduce pain and biting force in bruxism; they do not show that bruxism goes away. A systematic review of 4 randomised controlled trials found that botulinum toxin injected into the masseter and/or temporalis muscle can reduce the frequency of bruxism episodes, pain and maximum biting force, and that it showed a more marked effect than placebo or traditional methods (oral splints worn at night, medicines, cognitive-behavioural therapy) (Fernández-Núñez et al., 2019).

In a meta-analysis of 10 studies, botulinum toxin reduced biting force and pain compared with oral splints and saline injections; the effect appeared before 4 weeks, peaked at 5–8 weeks and lasted up to 24 weeks. The benefit of Botox appeared early but gradually diminished, whereas splints had a more enduring effect, especially after 9–12 weeks; Botox was recommended as an option for people who struggle to wear a splint or want earlier relief, and effects beyond 24 weeks and after repeated injections have not yet been studied enough (Chen et al., 2023).

Bruxism is a medical topic: if you have symptoms, it is appropriate to be assessed by a dentist or physician before deciding on Botox.

Possible Side Effects and Who Should Not Have It

Masseter Botox is considered for people over 18 whose general health is suitable; in the following situations it is postponed or not carried out:

• Pregnancy and breastfeeding
• Known allergy to botulinum toxin or to any of the product ingredients
• Neuromuscular conditions such as myasthenia gravis
• Active infection or an inflamed skin problem in the treatment area
• A bleeding disorder or regular use of blood thinners (planned with physician assessment)

Common, temporary side effects are redness, tenderness and small bruises at the injection points and a mild headache in the first days; less commonly, asymmetry or a change in expression can occur, and these resolve as the effect wears off. Rare ones are infection and prolonged muscle weakness. In a review of 36 articles on complications of masseter injections, most complications appeared within 2–4 weeks and disappeared within 12 weeks; knowing the regional anatomy and injection safety zones is stressed (Yeh et al., 2018). Because studies measured a reduction in biting force, ask any questions about chewing at the consultation. If you notice an unexpected, severe or prolonged symptom (for example a marked asymmetry when smiling or chewing), contact the clinic; if there is a sudden, serious symptom such as difficulty breathing or swallowing, go to an emergency department without delay.

What to Ask When Choosing a Doctor

When choosing a doctor, check whether the person treating you is a medical doctor, whether the product is approved, whether the dose is planned individually and whether there is a follow-up visit:

• Who performs it: Is the person treating you a medical doctor?
• Product: Is it approved by the Ministry of Health, and how can its licence be checked? For details see our guide to spotting counterfeit botox.
• Assessment and dose: Is the cause of the wide lower face (muscle, bone, fat, skin) assessed at the examination, and are the dose and injection points planned individually?
• Follow-up: Is there a follow-up visit to assess the result?

At Dr. Doğan Uysal's clinic in Mezitli, medical doctor Dr. Doğan Uysal performs Botox himself; treatments are carried out with Ministry of Health–approved products, in a sterile environment and with an individualised dose plan. Clear information on the price is given at the first consultation after the facial analysis; treatments that are not needed are not recommended. For a more detailed checklist see our guide to choosing a Botox doctor and clinic.

The decision on suitability and the plan is made at a face-to-face examination. You can reach the clinic by phone or WhatsApp at 0538 279 38 33 or through our contact page; Turkish, English and Russian are spoken, and the clinic in Mezitli is about 10 minutes from Mersin city centre. For all botulinum toxin treatments see our Botox page, for the other areas of the face our article on where botulinum toxin is applied and for the general effect timeline our article on how many days until Botox takes effect.

Frequently Asked Questions

Does masseter Botox slim the face?

Yes, if the width of the lower face comes from a prominent chewing muscle (masseter). Botox gradually reduces the volume of the muscle and the lower face gains a softer, more oval contour. If the width comes from bone structure, fat tissue or skin laxity, Botox does not remove it; this distinction is made at the examination.

When does masseter Botox start to work?

The effect becomes noticeable within 15–20 days. Because the reduction in muscle volume progresses over weeks to months, studies have reported the maximum effect of a single session at about month 3, and at 5–8 weeks in bruxism studies.

How long does masseter Botox last?

It varies from person to person; to maintain the slimming effect, a repeat every 3–6 months is generally recommended. In studies the effect of a single session lasted 6–12 months, and up to 24 weeks in bruxism studies; as sessions are repeated the slimming effect often becomes longer-lasting.

How is masseter Botox done?

First the face and jawline are examined, your medical history is reviewed and the dose is planned individually. The injections are given into the masseter muscle with fine needles; they are completed in a few minutes, Botox treatment usually takes 15–20 minutes and no anaesthesia is needed. It is recommended not to lie down for the first 4 hours and to avoid intense exercise that day.

Does Botox work for teeth clenching (bruxism)?

Studies report that masseter Botox can reduce pain, biting force and the frequency of bruxism episodes; they have not shown that bruxism goes away. The effect appears early but diminishes over time, whereas splints worn at night may have a more enduring effect. If you clench your teeth, an assessment by a dentist or physician is recommended first.

What are the side effects of masseter Botox?

Common ones are redness, tenderness, small bruises at the injection points and a mild headache in the first days. Less commonly, asymmetry or a change in expression can occur; these resolve as the effect wears off. A review reports that most complications appeared within 2–4 weeks and disappeared within 12 weeks.

Who should not have masseter Botox?

It is not given to people under 18; it is not carried out, or is postponed, during pregnancy and breastfeeding, in people with a known allergy to botulinum toxin or to product ingredients, in neuromuscular conditions such as myasthenia gravis and when there is an active infection in the treatment area. A bleeding disorder or regular use of blood thinners is planned with physician assessment; the decision is made at a face-to-face examination.

Where can I have masseter Botox in Mersin?

For masseter Botox in Mersin you can visit Dr. Doğan Uysal's clinic in Mezitli (Ofisium İş Merkezi, Yeni Mahalle, Gazi Mustafa Kemal Blv. No:665 6/24). Botox is performed by medical doctor Dr. Doğan Uysal himself; to book an appointment you can call or message on WhatsApp at 0538 279 38 33.