Tech Tip: Why do my patient’s teeth still need movement at the end of treatment?

Question:

My patient has finished wearing their final aligner, but some of the teeth still aren't where we want them to be. What gives?

Answer:

First, make sure that your patient has been wearing their aligners for at least 22 hours a day. You can ask your patient, of course, and you can also verify wear by checking for occlusal scuffing and slight yellowing of the aligner material. Patient non-compliance is a common reason for teeth not tracking.

Even if the patient has been wearing the aligners regularly, it's very common for cases to require overcorrection to acheive ideal results.The final aligner should match the shape shown on the treatment setup—however, this doesn't always actually move the teeth into that position. It may be necessary to apply additional force by creating aligners with the teeth moved farther than you actually desire.

This is not unique to ClearCorrect. Age, sex, root length, bone levels, bone density, medications, and some systemic conditions can all affect the effectiveness of treatment. Studies show that orthodontists often fall short of their goals, especially for certain types of tooth movement. 

Overcorrection is especially likely to be needed for these types of movement:

  • Rotations (particularly single-rooted teeth whose roots have a circular cross-section)
  • Labial-lingual alignment (particularly of incisors)
  • Expansion
  • Extrusion (because the PDL tends to pull the tooth back into the socket)

If you know you're going to need overcorrection, you can request it upfront in your initial prescription. Just be sure to keep an eye on those teeth so they don't move too far. 

It's always safest to err on the side of caution—if you submit your case as Unlimited, additional phases won't add to your lab fee. When you submit a Limited 6 or Limited 12 case, you should be prepared for the possibility of purchasing an additional phase.

Make sure your patient is aware that there is no guarantee of acheiving results within a certain timeframe. Make sure they're aware that additional treatment may be required after the final step. (Some of this is covered in the required informed consent & agreement, but you'll probably also want to attach your own conditions regarding fees and outcomes.) It's better for everyone when you set realistic expectations at the beginning of the case.

Until next time…

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