Tech Tip: Difficult tooth movements

Not all tooth movements are created equal. As our case parameters guide explains, tooth movements can be easy, moderate, or difficult depending on the direction and distance of movement. When a tooth needs to perform a difficult movement (such as intrusion or extrusion), an aligner may not apply enough force by itself.

Here are some methods you can use to complete those difficult tooth movements without resorting to case revisions.


When treatment gets off track and the next set of aligners doesn't fit, the teeth may just need more time to make those difficult movements. This is especially true if the patient hasn't stuck to the recommended wear schedule of at least 22 hours per day. All the case revisions in the world won't help if the patient doesn't wear the aligners regularly.

Use the models from the last step that fit to create a fresh pair of aligners in your office. A fresh pair of aligners will have more resilience and tension than a three-week-old aligner. Advise your patient to wear those aligners for another week, or until the aligners feel loose. If they stick to the schedule, it's likely that the next set of aligners will fit when they're done.

You can use a standard thermoforming plastic like Biocryl or Essix, or (if you have the right equipment) a premium material like Zendura. If you're all out, just give your account rep a call at (888) 331-3323 to place an order.

If you're sure the patient is being compliant and you've tried backtracking and breaking tight contacts, but the next set of aligners still doesn't fit, then the teeth just might be plain old stubborn. Then it's probably time to order a case revision.

Dealing with broken engager templates

Engagers give the aligner extra leverage to complete difficult movements. We include an engager template whenever it's time to install engagers.

If the engager template breaks, we'll be happy to replace it. Of course, it will take at least a few days to manufacture and ship. (And again, if you're out of phases, you might need to buy a step.) Fortunately, there is a quick & easy alternative that keeps your patients in active treatment:

Let's say that your patient is currently wearing step 3B, and comes to your practice for his 3C fitting appointment. As you prepare to place the engager, the template breaks.

Instead of waiting for a replacement template, just let your patient wear the step 3C aligners without engagers. Have your patient come back for an interim appointment three weeks later. There, you can use the worn-out 3C aligners as engager templates for the next step.

(A guide to placing engagers is available in the Documents section of ClearComm.)

Extruding teeth with auxiliaries

When a tooth does not erupt as desired, you can apply some extra force with auxiliaries by following our step-by-step guide. The treatment plan will never instruct you to place auxiliaries -- this is an advanced technique that you can use yourself whenever you see fit.

(This guide is also available in the Documents section of ClearComm.)

If you have any other suggestions or tips that you'd like to share, please leave a comment and let us know!

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