Most aligner problems do not appear suddenly. They start as small signals: a gap here, a tight contact there, a stage that never quite fits. The earlier you notice them, the cheaper they are to fix.

This guide lists seven warning signs that a case needs a second look, what each one usually means, and what to do next. At the end you will find a one-page checklist you can use at every review.

Sign 1: The aligner does not seat fully

If a patient shows a visible gap between the aligner and the tooth surface, especially at the biting edges or around attachments, the aligner is not tracking the planned movement.

What to check

• Is the patient wearing each aligner for the full time you prescribed?
• Did the previous stage really finish its movement?
• Were chewies or other seating aids used as instructed?

What to do: if the gap stays after consistent wear, do not move to the next stage. Review the plan, and consider going back a stage or ordering a refinement.

Sign 2: The plan asks too much in one step

Heavy movements packed into a single stage are a common cause of poor tracking. Large rotations, extrusions or tipping movements in one step may not be realistic.

What to check

• Which movements are the most demanding in the plan?
• Are they spread across several stages, or stacked together?
• Does staging match what you expect for this type of case?

What to do: ask for the staging to be reviewed before production. See our guide to aligner QC service for what a review looks at.

Sign 3: Attachments are missing, damaged or in the wrong place

Attachments help aligners grip the teeth and apply force. If they are lost, worn down or placed where they cannot do their job, movement suffers.

What to check

• Are all planned attachments present and intact at each visit?
• Do their positions match the plan?
• Are they on usable tooth surfaces, with enough enamel and room?

What to do: replace lost attachments promptly, and flag any placement that does not match the plan.

Sign 4: The bite is changing in ways you did not plan

New open bites, early contacts or collisions between teeth can appear during treatment. Some are expected and corrected later in the plan. Others are signs of a problem.

What to check

• Does the final position show a healthy bite on screen?
• Are there planned or unplanned contacts at each stage?
• Do the patient’s reports of how their teeth meet match the plan?

What to do: compare the current bite with the planned stage. If they differ, review the plan before continuing.

Sign 5: The result drifts from the prescription

Sometimes the setup you receive is not exactly what you prescribed. Midlines, tooth positions or end-of-treatment goals may differ from your instructions without anyone noticing.

What to check

• Does the final position follow your written prescription tooth by tooth?
• Were your earlier change requests really applied?
• Is the midline where you want it?

What to do: compare the setup with your prescription line by line before approval, and do not rely on a quick glance.

Sign 6: IPR and spacing do not match reality

Interproximal reduction (IPR) that is planned in the wrong place, in the wrong amount or at the wrong stage can leave tight contacts or unplanned gaps.

What to check

• Was the IPR done at the planned stage and in the planned amounts?
• Are contacts tight where the plan expects space?
• Is spacing opening where it should not?

What to do: check the plan against what was done in the mouth, then decide whether to adjust the IPR or the plan.

Sign 7: The scan or model had problems from the start

A plan built on a flawed scan carries the flaw forward. Missing areas, distorted surfaces or poor bite registration can make every stage slightly wrong.

What to check

• Were the scans complete and clean?
• Did the aligner fit well from the very first stage?
• Is the model free of holes and defects? See our guide to Meshmixer for aligner models.

What to do: if the first aligners already fit poorly, consider a new scan before spending more time on the current plan.

Your one-page aligner case checklist

Use these questions at setup approval and at each review visit. If any answer is no or unsure, pause and review.

Check	Yes	No
Does each aligner seat fully, with no gaps at edges or attachments?
Are the planned movements realistic for each stage?
Are all attachments present, intact and correctly placed?
Does the bite look right now and in the planned final position?
Does the setup match my written prescription?
Do IPR and spacing match the plan?
Were the scans and models clean from the start?

When to ask for a second opinion

A second look is most useful when:

• A case is not tracking after consistent wear
• You are about to approve a complex setup
• You are new to aligner planning and want a safety net
• A previous case with the same pattern did not go well
• You plan many cases and worry about fatigue errors

Not sure whether a case suits aligners in the first place? Review our guide to treatable cases.

How OrthoAlign Solution can help

Our QC Service gives your aligner setups an independent check before you approve them, so problems are found on screen instead of in the patient’s mouth. Add your own details here about what your QC review covers and how long it takes, so readers know what to expect.

Frequently asked questions

How do I know if an aligner is tracking properly? The aligner should sit snugly against the teeth and attachments, with no visible gaps after consistent wear. Persistent gaps are a sign to review the case.

Should I always order a refinement if a case is not tracking? Not always. First rule out compliance issues, lost attachments and unrealistic staging. Then decide between going back a stage, a refinement or a new plan.

Can a second look prevent these problems? Many of them, yes. A review before production catches plan errors early, when they are easiest to fix.

Is this checklist only for new aligner providers? No. Experienced clinicians also benefit, especially on complex cases or when working at high volume.

Can I use the checklist for patients treated by an outside planner? Yes. It works for any setup, whoever planned it.

Get a second pair of eyes on your next case

Send us a setup and see what a review can find. Visit our QC Service page, or contact OrthoAlign Solution to get started.