There are any number of reasons your case might need a revision, the most common being when teeth don't move as planned. You can check for any of the following possible issues that can potentially be resolved without having to submit a revision:
Aligners don't fit - Incisal Gaps

An incisal gap (large or small) is when there is a gap between the incisal edge of the tooth and the aligner. Incisal gaps are usually the first sign of a case going off track.
Troubleshooting options:
Aligners don't fit - Rocking

Rocking is when one side of the aligner first but the other does not. The side that is tracking will fit nicely (flushed), but the side that is tracking poorly will not want to sit at all.
Troubleshooting options:
- Check for impression distortions in the original impression
- Try the following steps:
- Seat the aligner on one side
- Align the aligner over the teeth on the opposite side
- Using your thumb on the aligner over the first molar, push the aligner toward the teeth
- Rotate the thumb down and toward the gingiva, torquing the aligner onto the teeth
- Section the aligner at the midline and seat each half independently
Non-compliant patients

Non-compliant patients are patients who are not following their recommended wear schedule (at least 22 hours a day). Compliance is the most common reason things go off track during treatment.
Troubleshooting options:
- Document the non-compliance
- Re-state wearing instructions and importance
- Show them their treatment setup so they know what results await if they stick to their treatment plan
- Extend the time the patient has to wear their current aligners
- Remind them of the alternative treatment (braces) & about the time/money spent on clear aligner treatment
- Consider terminating the patients treatment vs. having the treatment fail
Tight Contacts

Tight contacts exist when there is tension or compression between two teeth. Tight contacts between teeth exist naturally when the collective size of the teeth (the cumulative total of the mesiodistal width of all teeth in an arch) is larger than the amount of room available for those teeth in the supporting bone. The natural condition of properly aligned teeth in a dental arch does not find them tightly compressed together into a "tight contact", only "in contact with each other."
Troubleshooting options:
- Floss between the suspect teeth to check for tight contacts
- Check subgingival too
- If tight contacts exist, hand stripping can be done to create 0.1 mm of IPR
You can find more information about clear aligner treatment, invisible braces and/or ClearCorrect in our online Help Center.