Arch Expansion in Orthodontics: What is it?

Straight Teeth TV Season 2 is out now!

Join our CEO and co-founder Dr. Aalok Y. Shukla to learn all about the science of teeth straightening using invisible aligners, starting with arch expansion. This process is key to remote cosmetic orthodontics, so what is arch expansion?

#1 What is orthodontic expansion

In short, arch expansion or orthodontic expansion is the process of creating space for your teeth. When there isn’t enough space for your teeth to align next to each other, they become crowded or crooked, sometimes twisting, turning or overlapping. During arch expansion, all the visible teeth in your smile move outwards in small increments, giving your teeth up to 4.5mm of extra arch room to align. 

This is the process used for remote teeth straightening with invisible aligners. It is comfortable, safe and achieves impressive results for both mild and moderate cases.

#2 Arch shapes: genetics of teeth arch expansion

In arch expansion, it’s important to understand the effects of genetics – in this case, natural arch shapes:

• V-shaped arch: this dental arch is generally narrower to begin with and the bone profile makes it appear less straight. It is also the jaw shape where misalignment is most likely to happen!
• U-shaped arch: compared to the v-shaped arch, the u-shaped one generally allows for a bit more space and teeth to sit next to each other more easily
• Square shaped arch: this is the flattest arch shape and the most ideal with regards to space

#3 How aligners create space between teeth

No matter your genetics, teeth can always move in and out of alignment – even after having braces! As mentioned above, aligners expand your dental arch and create more space between the teeth. Each aligner represents the position of your teeth after two weeks of use, meaning your future tooth position. One by one, each aligner moves your teeth by a fraction of a millimetre and, over time, the entire dental arch expands enough to accommodate the front teeth in a new, straight formation. This method can be used in up to 80% of cosmetic teeth straightening cases, where a natural looking smile with the best tooth alignment is desired.

#4 Three things that affect arch expansion

So, can arch expansion with invisible aligners be used in every case? As always, there are more factors that come into play here. The arch expansion potential for each individual case depends on three things:

1. Biological limits of what is actually possible for you, based on your arch configuration
2. Gum biotype, meaning how thick your gums are and how much they protect and support your teeth
3. Physiological response to the treatment, so how your teeth actually respond to the aligners (which cannot always be predicted)

#5 Straight Teeth Direct’s transparent treatment plan

At Straight Teeth Direct™, we don’t like leaving things to chance – least of all your smile! That is why all the above mentioned influencing factors that make your teeth appear crooked are taken into account when creating your detailed orthodontic Straight Teeth Plan and 3D smile simulation.

Your individual treatment plan provides you with detailed information on your jaw configuration, achievable results for your unique case, as well as 3D renderings of the predicted teeth straightening treatment process. This means you understand your current dental situation and achievable future results with optimum treatment before committing.

There is no pressure to commit to treatment unless you feel 100% happy with your predicted results, after which you can order your StraightBox™ teeth straightening kit that includes your first aligner shipment!