Topics covered:

• Definition, causes and recommended solutions for prescribing crowded cases
• Techniques for prescribing crowded cases including; proclination, expansion, distalization, and IPR

Definition

Crowding of teeth is where there is insufficient room for the normal complement of adult teeth.

Causes

There are many possible causes for malocclusion, including the size and shape of the teeth, the form of the dental arches, the relationship of the skeletal components and patient's own harmful habits. 

Determining the cause of each patient's malocclusion is essential for successful diagnosis, treatment planning and prognosis.

Some common causes for crowding are; extra teeth, lost teeth, impacted teeth or abnormally shaped teeth.

Please see our series of videos on the topic of malocclusion in our Basics of Orthodontics series.

Solution

The simplest option is to check “only if needed” and allow our dental technicians to offer their recommendations.

If you have specific preferences for a patient's treatment, though, please let us know when you submit your case. At ClearCorrect, doctors are in charge. We will customize the clear aligners to carry out whatever treatment you prescribe to the best of our ability. If you don't see an option on the form, feel free to provide special instructions in the “additional instructions” section.

For patients with severe crowding, it's usually best to use a combination of techniques. For instance, proclination and expansion are more predictable together than either technique alone.

If the crowding is not too severe, however, you may be able to achieve your goals with just one of the four options (procline, expand, distalize, or IPR).

Techniques for crowded cases

Following are the four main techniques for crowded cases, and when we recommend using each one:

Procline

Proclining teeth is a useful way to give a patient fuller lips or a fuller side profile. This is recommended for older patients whose lips are a little “droopy.” This can also be desirable for people who have a flat profile.

To check if a patient needs to be proclined, draw a line from the tip of the nose to the tip of the chin on a non-smiling profile picture. In an ideal profile, the upper lip should almost touch the line and the lower lip should overlap it slightly.

If both lips are well behind the line, the patient might benefit from proclination. If both lips are well past the line, lingualizing the teeth might improve the patient's profile. (Lingualization isn't one of the standard options, but you can request it in the “other instructions” section.)

Expand

Expansion is the most common method we use to create space. It should be used when there is visible space between the posterior teeth and the cheeks when the patient smiles. A wider smile that shows more teeth can help your patients “light up the room.” Think Julia Roberts or Anne Hathaway.

Distalize

We often recommend distalizing the anterior teeth and/or premolars 1-3 mm if you want to achieve a Class I bite and improve the patient's chewing function. We don't recommend distalizing molars; they're very difficult to translate. Distalizing and mesializing less than 4 mm per quadrant keeps the movements more predictable and reduces the chance of interference with other teeth. Of course, if you want to try for more than 4 mm, you can always request that in the “additional instructions” section.

IPR

We like to avoid IPR (interproximal reduction) whenever possible. However, IPR is sometimes necessary to create space for very crowded teeth to move. IPR can also be used to treat a case quickly by keeping the teeth in their current positions and just rotating them into alignment.

We usually recommend IPR when we are aligning both arches and we need to reduce the width of the teeth on one arch to get proper overjet. In this situation, IPR is usually only needed on one arch.

We can also use IPR to put premolars or canines into a Class I relationship, or to correct a midline misalignment.

As providers treat more patients, they usually get a feel for which techniques work best for them. If you have any comments, or preferred techniques and tips, please share them by emailing us at support@clearcorrect.com.