Orthotown March 2020 - 30

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Clear Aligner Therapy
A case where clear aligners come up short, but traditional expertise can get the job done

dmachen47
Member Since: 12/21/12
Post: 1 of 5

Has anyone had success using clear aligners to move a maxillary second molar into the place
of an extracted maxillary first after failed endo treatment? ■
1/28/2020

Terry Gruelle
Member Since: 05/03/08
Post: 2 of 5

No! With more than 5,000 aligner cases under my belt, I am totally unimpressed with my
ability to move U7s in any direction except intrusion. Of course, I'm talking about 7s that aren't
erupting, but present in a static malocclusion. Buccal crossbites need cross-bite elastics from day one.
Buccal root torque, which most seem to need, is difficult. The wide contact between the 7s
and 6s makes it harder to open to avoid collisions. IMO, that is the biggest issue, because the
aligners will "shorten" at the terminal end due to mechanics placed for movements on teeth more
anterior. Expansion is possible, but it depends on what needs to be done with the other posterior
teeth. Do they need expanding, rotation, extrusion, etc.?
Distal root tip. I have placed every type of attachment possible with no predictable recommendation. These include attachments on the buccal and lingual, and dual attachments as well.
Back to your question: I have failed at using Class III elastics. The elastics often pull the teeth
out of the aligners. There is no predictable way of knowing how fast the tooth will move and how
to program that in so the aligners can keep up with the tooth movement.
Although I love power arms, I've not found them reliable to allow the roots to come forward
first/gable.
The issue is keeping the 7s in the aligners: They rotate, they extrude out of the aligner, they tip.
IMO, interarch elastics are not predictably good for 7s. So that leaves intraarch mechanics.
But can one move the 7s' roots mesial first before the crown movement, and do it enough times
to close a 10mm space? I will not try again.
I have an hour presentation that I call "7s UP" to show my failures with the upper 7s over
the years. Good luck to all. ■
1/29/2020

justinudm
Member Since: 09/29/14
Post: 3 of 5

Here is a case where I moved an UL7 into an UL6 position. The first set of photos is the
initial, taken 9/13/18. Note that the UL6 has a temp crown; the patient's dentist contacted me
and asked if I could substitute the UL7 for the UL6 and allow the UL8 to erupt. I said, "Yes, we
can, but it will require traditional braces."
My initial plan was to use a MARPE because the 15-year-old patient had a transverse skeletal
issue. Note that the lower posteriors are tipped lingually and the upper posteriors are tipped buccally.
Because the intermaxillary suture may have been starting to fuse at this age, I decided to
go straight to a TAD-borne Moon expander or MARPE. My plan was to then cut the arm to
the UL7 off the MARPE, have the GP extract the UL6 and use the anchorage of the MARPE
TADs to protract. I waited to extract the UL6 until I was in a large, rectangular steel wire and
ready to protract. I did this because I did not want pneumatization of the maxillary sinus to
occur. Well, the patient didn't keep the MARPE clean and the palatal tissue overgrew, so that
plan went out the window.

MARCH 2020 // orthotown.com

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