Aligner staging: where series fail
A plan that looks smooth in software can stall at stage 12. The cause is usually movement per stage, not the aligner material.
Movement per stage
Thermoformed aligners have an elastic limit. When a stage asks for more rotation or translation than the material can deliver, the aligner seats but does not move the tooth, and the tracking failure appears two or three stages later.
We review the plan for per-stage movement before printing and re-order the stages that exceed the limit, rather than printing a series that will fail.
Attachment design
Rotations need attachments; extrusions need them more. A plan without the right attachment geometry will not deliver the movement, and the attachments cannot be added later without re-planning.
Retention was decided at the start
If retention is planned after the last aligner, the patient spends weeks without it. We include retainers in the same order by default.