All About Arch Wires - Biermann Orthodontics

All About Arch Wires in Orthodontics: Purpose, Types, and Recommended Uses

If you’re considering braces, you may have heard the term arch wire used. But you probably have no idea what that means!

We’ll explain what orthodontic arch wires are, the purpose they serve, and what types may be used in your braces. And if you’re interested in straightening your teeth without the use of wires, we can fill you in on that as well.

Table of Contents

What Is an Arch Wire?

An orthodontic arch wire is the wire that attaches to your braces. It is called an “arch wire” because your top teeth comprise your top arch, and your bottom teeth comprise your bottom arch. 

An arch wire is like the engine that guides and moves your teeth. Without an arch wire to connect your braces, you would just be wearing braces for fun and your teeth would never move! These braces wires come in different sizes and have different material compositions.

What Is the Purpose of the Arch Wire?

When you first start treatment with braces, your teeth are crooked. The wire that attaches to your braces must be able to return to its original shape when it is deformed or bent. The force that returns the wire to its original shape is what moves your teeth. The wire should be springy, yet exert a gentle force so that your brackets do not pop off when the orthodontist ties in your arch wire.

As your teeth get straighter, your orthodontist will exchange the wire in your braces for stronger wires that are usually less elastic and stiffer. These stronger, stiffer wires allow the orthodontist to have more control over tooth movements. Oftentimes, these later wires have characteristics that allow the orthodontist to put permanent bends in the arch wire if he wants to move individual teeth.

What Are the Different Types of Arch Wires?

When orthodontists discuss the different types of arch wires, they are typically referring to either the size/shape of the wires or the materials they’re made with.

Arch wires come in round or rectangular shapes, and they may be composed of stainless steel, nickel-titanium, or beta-titanium.

Size and Shape of Arch Wires

When orthodontists talk about the “size” of an arch wire, they are referring to the cross-section or thickness of the wire. Considering arch wires made from identical materials, the smaller the cross-section, the more elastic and less stiff the wire will be. 

Wires come in two types of cross-sections: 

  1. Round – These dental braces wires are round in a cross section.
  2. Rectangular – Rectangular wires can be square or rectangular in a cross section.

In the beginning stages of treatment, round wires are typically used to level and align the teeth. This is because when considering arch wires made from identical materials, round wires are more elastic and so the orthodontist will be able to engage all your teeth into the wire without popping off brackets. 

If the orthodontist uses a wire that is too stiff and tries to tie the arch wire to a really crooked tooth, the wire will put too much pressure on the bracket, and the bracket may break off from the tooth.

After the teeth are straighter, orthodontists usually advance to rectangular wires. Because the wire slot of the bracket is rectangular, a rectangular wire fits into the bracket like a hand fits into a glove. 

In the beginning, the smaller rectangular wire may be like a small hand in a large glove. However, by the end of treatment, the rectangular wire you have may be more like a large hand in a large glove. By fitting snugly into the bracket, the rectangular wire controls tooth movement better than a round wire.

Arch Wire Materials

Now that you understand a little about why orthodontists like elastic wires in the beginning of braces treatment and stronger, stiffer wires at the end of treatment, let us consider what materials the arch wires are made of.

There are three main types of material compositions for arch wires: 

  1. Stainless steel
  2. Nickel-titanium (Ni-Ti)
  3. Beta-titanium

Let’s look into these a little further.

Stainless Steel Braces Wires

Stainless steel wires have been used for decades due to their high strength. In addition, stainless steel wires do not rust and can be adjusted in many different ways by the orthodontist without breaking. 

However, stainless steel wires are not very elastic, meaning that if you bend these wires too much, they will assume the new position and will not return to their original position. 

In the beginning stages of treatment, it is important for the wires to be elastic so that the wires can bounce back to a nice smooth U-shape and carry the teeth with them at the same time. In the initial stages of aligning very crooked teeth, stainless steel wires may not be the best option.

Nickel-Titanium Braces Wires

Nickel-titanium (Ni-Ti) wires are elastic and can return to their original shape when deformed. Therefore, in the beginning stages of orthodontic treatment, Ni-Ti wires are frequently used to put gentle forces on the crooked teeth to align them. 

A variation of Ni-Ti wires is heat-activated Ni-Ti (copper Ni-Ti) wires. Heat-activated Ni-Ti wires can hold the deformed configuration at room temperature, but when the wire reaches the temperature of a patient’s mouth, the wire will return to its original shape. 

Heat-activated Ni-Ti wires are useful in the beginning stages of treatment. If the teeth are extremely crooked, the wire can be cooled so it can be tied into the brackets easier. Then after a few minutes, it will reach the temperature of the patient’s mouth, displaying its Ni-Ti elastic properties. The warm wire will want to assume its original U-shape and carry the teeth to their new, straighter positions.

Beta-Titanium Braces Wires

Beta-titanium wires were developed after Ni-Ti wires and offer an intermediate range of elasticity and strength while also being able to be permanently deformed. 

This wire serves as a good intermediary wire between Ni-Ti and stainless steel. Some orthodontists will use this wire starting in the middle of treatment while other orthodontists do not use this type of wire at all.

What’s the Best Orthodontic Arch Wire To Use?

So which arch wires will your orthodontist use? It is difficult to say because all patients are different and all orthodontists have their own technique for adjusting braces. 

Some orthodontists only use Ni-Ti wires while other orthodontists only use stainless steel wires. However, most orthodontists typically start with small Ni-Ti wires to align crooked teeth in the beginning and then progress to larger stainless steel or beta-titanium wires when more control of teeth is necessary.

Many patients think that their wires need to be changed at every visit. This is usually not true. With the wide assortment of wires these days, your orthodontist may only need to use three to five sets of wires during treatment. More wires may be needed for complicated cases.

Is It Possible To Straighten My Teeth Without Using Wired Braces?

Yes, it is! Many people want straighter teeth and a more beautiful smile without the hassle of having wires attached to their teeth. 

For these patients, we highly recommend Invisalign. This series of digitally-designed, nearly invisible aligners will straighten your teeth comfortably, plus you can remove them when needed.

Biermann Orthodontics is a Diamond Plus Invisalign Provider, meaning we are in the top 1% of orthodontist’s offices that provide this service.


See if Invisalign will work for you, and then contact us today to set up a consultation.

Stephen Yang, DMD, MS, is a writer and Senior Editor for Dr. Yang received his Bachelors degree in Psychology at the University of California at Los Angeles. Following his undergraduate studies, Dr. Yang attended the Harvard School of Dental Medicine, where he completed his Evidence-Based-Dentistry thesis and obtained his Doctor of Dental Medicine degree. After receiving his doctorate, Dr. Yang went on to study at the University of Southern California where he received his Certification in Orthodontics. Concurrently at USC, he completed his thesis on one phase versus two phase treatment in patients with large overbites, and obtained his Masters of Science in Craniofacial Biology.

Dr. Yang is a Board Certified Orthodontist, practicing in Antioch, California. He is a Certified Invisalign Provider, and is a member of the American Association of Orthodontists, Pacific Coast Society of Orthodontists, American Dental Association, and California Dental Association.

Original Article:

Looking for an orthodontist in Beaverton, Oregon? Biermann Orthodontics is a cutting-edge orthodontic practice that serves Beaverton and Molalla, OR, and focuses on providing world-class customer service and efficient treatment. We strive to create stunning smiles in the shortest amount of time without ever sacrificing quality.

Visit our Locations page to find a clinic near you, or schedule an initial consultation.

Biermann Orthodontics

17885 NW Evergreen Parkway, Suite 200
Beaverton, OR 97006


The content in this blog should not be used in place of direct medical advice/treatment and is solely for informational purposes.