What is Botox and how does it work?

“Botox” is the popular name; the medical name is botulinum toxin type A. It temporarily reduces the “contract” signal travelling from the nerve to the muscle. As a result, the treated muscle contracts less, and the lines created by that muscle’s movement soften.

The effect starts within a few days, becomes clear in about two weeks and usually lasts a few months. Muscle movement gradually returns. Textbooks stress that Botox gives effective and safe results particularly in the upper third of the face (forehead, between the eyebrows, the outer corners of the eyes), while in the lower face it should be used more cautiously because of speaking and eating functions.

What are fillers and how do they work?

A dermal filler is a substance placed under the skin or in deeper tissues to replace lost volume. Today the most commonly used type is hyaluronic acid (HA) filler. Thanks to its ability to hold water, HA provides volume and support to the tissue.

The result of a filler is usually visible immediately after treatment; the final look appears as the swelling of the first days goes down. How long it lasts varies by area and product; the body gradually breaks the filler down. An important safety feature of HA fillers is that they can be dissolved by a doctor with an enzyme called hyaluronidase if necessary.

What are the differences between Botox and fillers?

Why does the difference between dynamic and static wrinkles matter?

The key to choosing the right treatment is when the wrinkle appears:

• Dynamic lines: Appear only with expressions such as raising the eyebrows, frowning or smiling. They are caused by muscle movement, so Botox is the first option that comes to mind.
• Static lines: Are visible even when the face is at rest. Years of repeated movement, reduced skin elasticity and volume loss make these lines permanent. In this case fillers, skin rejuvenation methods or a combination of methods are considered.

For example, forehead lines are completely dynamic at first; over the years they start to show at rest as well. In such a case, Botox alone may not erase the line completely.

What is each used for in dentistry?

Medical Botox and fillers should not be thought of as purely cosmetic; they have uses directly related to the mouth and jaw area.

Dentistry-related uses of Botox

• Teeth clenching and grinding (bruxism): Can be used as a supportive measure to reduce the load on the teeth and jaw joint by reducing the strength of the chewing muscle; it does not replace a night guard.
• Masseter muscle enlargement: Can be considered for a square jaw appearance caused by a thickened muscle.
• Muscle-related gummy smile: One of the options when it is caused by muscles that lift the upper lip too much when smiling.

Dentistry-related uses of fillers

• Lip support and contour: For thinning or asymmetric lips.
• Volume loss around the mouth: For smile lines and lines running down from the corners of the mouth.

As dentists, we want to add an important caution here: the cause of a sunken look around the mouth is sometimes missing teeth, a resorbed jawbone or teeth that have worn down and become shorter. In that case a filler only corrects the appearance temporarily; the real problem is solved by treating the teeth, the bite and the bone support. For patients planning implant, denture or orthodontic treatment, it is better to decide on fillers together with these treatments.

Can Botox and fillers be combined?

Yes, in many cases the two methods complement each other. While Botox reduces the movement that creates the line, a filler can support an established line and volume loss. The doctor decides after the examination which area is treated, in what order, and whether in the same session or on separate days.

The order also matters in treatment planning at a dental clinic. For example, if a comprehensive smile design, crowns or implant treatment is planned, it often gives a more predictable result to assess treatments for the lips and surrounding tissues after the final shape of the teeth has been decided. This is because the length and inclination of the teeth and the bite height directly change the position of the lips. If you are planning dental treatment in Istanbul, it is worth discussing the timing of any Botox or filler with us at the same time. Likewise, if masseter Botox is being considered for a patient who clenches their teeth, the need for a night guard to protect new restorations is discussed as well.

Who should not have them, and what are the risks?

The main contraindications common to both treatments are pregnancy and breastfeeding, active infection or cold sores at the injection site, allergy to the product’s ingredients, bleeding disorders and uncontrolled systemic diseases. For Botox, neuromuscular diseases such as myasthenia gravis and certain medicines that affect nerve-muscle transmission are also important. For fillers, an untreated tooth or gum infection in the mouth is a reason to postpone treatment.

Side effects of Botox are mostly temporary and improve as the effect of the product wears off. With fillers, situations requiring emergency intervention, such as vascular occlusion, can occur, although rarely. For this reason both treatments should be carried out by a trained doctor who knows facial anatomy well, after an examination.

Frequently asked questions

Related pages

Medically reviewed by: Dr. Dt. Mehmet Fuat BozabaSpecialist in periodontology · September 2026

To find out whether Botox or fillers are right for you, you can message our clinic in Bahçelievler, Istanbul on WhatsApp or call +90 544 289 66 33.

Sources: Small R, Hoang D. A Practical Guide to Botulinum Toxin Procedures. 1st ed. Lippincott Williams & Wilkins (Wolters Kluwer), 2012. · Kontis TC, Lacombe VG. Cosmetic Injection Techniques: A Text and Video Guide to Neurotoxins and Fillers. 1st ed. Thieme, 2013. · Pirayesh A, Bertossi D, Heydenrych I (eds). Aesthetic Facial Anatomy Essentials for Injections. 1st ed. CRC Press, 2020.

This article is for information only; diagnosis and treatment planning are determined solely by a doctor after an examination.