Animations showing basic orthodontic techniques used with the Invisalign® system.

Extraction and arch expansion cases. | Tooth stripping. | Methods of correcting tooth crowding, rotations, inclinations and gaps.

This page features simple animations that illustrate the use of basic orthodontic techniques to straighten teeth.

And while the ones we show were chosen because they're frequently used with the Invisalign® system, they're also routinely used with all other types of dental braces too.

A) Closing spaces between teeth.

An animation showing how orthodontists close tooth gaps.

Closing tooth gaps.

Removable braces systems, like Invisalign®, are generally considered to be an appropriate treatment method for closing relatively small tooth gaps.
As a general rule of thumb, the total amount of spacing involved (cumulatively) should measure no more than 6mm per arch.

Here's a digital smile makeover that illustrates the type of tooth gap that Invisalign® might be used to close.


B) Crowded teeth are sometimes narrowed first, and then realigned.

Animation showing how crowded teeth can be narrowed, and then realigned.

Crowded teeth can be narrowed, and then realigned.

Some cases that involve tooth crowding can be transformed into, and then treated as, a case where the bulk of the tooth movement involves space closure.

With this approach, the dentist will shave down the crowded teeth just slightly using their dental drill or a diamond-coated strip (a process termed "tooth stripping").

It's then possible to use Invisalign® to realign the teeth within the same amount of space that already existed.


C) Resolving tooth crowding by "expanding" the patient's dental arch.

Animation showing how crowded teeth can be realigned by expanding the dental arch.

Crowded teeth can be realigned by expanding the dental arch.

Another approach that can be used with the Invisalign® system is to correct tooth crowding by flaring out the patient's teeth just slightly (expanding their arch).

With Invisalign® cases, the amount of arch expansion that's created (the amount of extra space made so the crowded teeth can be realigned) can be as much as 2 to 4 mm.


D) Extraction cases.

Animation showing how the space needed to realign teeth is sometimes created by extracting teeth.

The space needed to realign teeth is sometimes created by extracting teeth.

One way to create the space that's needed to realign crooked teeth is to extract one or more of them.

"Extraction" cases are commonplace in the orthodontic world. In most cases, they only involve the removal of back teeth (usually bicuspids), often in right/left pairs.

An example that involves front teeth.

This animation illustrates a case where a single crowded front tooth is extracted, and then the remaining 3 incisors are realigned into the space formerly occupied by all 4.

Philosophically this approach strays from the ideal (pulling a perfectly good tooth just as an orthodontic short cut). But from a practical standpoint, it's sometimes chosen.

When this method is used, it almost always involves the realignment of lower front teeth. And yes, the patient will end up only having 3 lower incisors (positioned in a space that's normally occupied by 4). But the vast majority of people who see this smile will never notice.

E) Rotated teeth can be realigned with removable braces.

Animation showing the realignment of rotated teeth.

Realigning rotated teeth.

Cases involving minor tooth rotations can be suitable candidates for Invisalign® treatment.

It's usually best suited for cases where the teeth have a rotation that's less than 20 degrees from normal.

"Attachments" may be needed for these cases. These strategically placed lumps of dental bonding help the aligners direct their forces to teeth in a way that without them Invisalign® might not be able to (efficiently, effectively) make the needed corrections.



F) Treating cases with both Invisalign® and conventional braces.

A picture showing a comparison of the appearance of Invisalign® vs. traditional braces.

Invisalign® vs. conventional braces.

It's possible that Invisalign® might be used for just a portion of a patient's total treatment plan.
  • The case might be started with traditional braces, so to accomplish those types of tooth movements that can be difficult for removable aligners to make.
  • And then, once that stage has been completed, the case finished using Invisalign®.

Since both types of braces are involved, the total
cost for this type of treatment plan would be expected to be greater than if it was treated with conventional braces only.