Backtracking is when you have a patient wear the previous aligners longer than originally planned. Often, when the teeth have gone off track, they need additional time in a previous aligner to move fully into position. Backtracking gives the teeth the time that they need to get back on track with treatment.
Indicators for when backtracking may be needed:
- An incisal gap
- Aligners not seating
- Aligners gradually worsening in fit
- Incomplete tooth movements
- If the patient has been non-compliant and hasn't stuck to the recommended wear schedule of at least 22 hours per day
Here's an example of how to backtrack:
Lets say there is a poor fit on aligner #15.
1. Ask the patient to return with their bag of aligners they have 'worn and saved'.
2. Starting with the aligner they are currently wearing (#15), have them try the previous set (#14). If it does not fit satisfactorily, ask them to put on the next previous aligner (#13). Repeat this process until you find a set of aligners that fit well, (lets say, for the sake of example, #12 fits well).
3. Then with the aligner that fits well (#12), have the patient begin wearing the next aligners in sequence, (#13) for 2 weeks each.
4. Progress forward through the series until reaching the last aligner that did not fit well (#15), then continue moving through the series of aligners as long as each aligner fits as it should.
A couple notes on backtracking:
- Patients should be educated to keep (do not throw away) their previously worn aligners through treatment.
- If your patient does not have their previous aligners, they can be remade by the lab. Keep your patient in their current aligners until these arrive.
- Backtracking may not work if some teeth have progressed and others have not. If you do not find an aligner that fits well, you may need to do a revision.