A method for generating a 3D digital, updated, model of a dental arch, including:



Acquiring at least one updated image. Each updated image representing an active aligner attached, in an operating position, to a dental arch, or ‘image with aligner’, or representing the dental arch without an aligner, or ‘image of uncovered teeth’.
Searching in an updated image, referred to as the ‘updated analysis image’, for representations of teeth that are non-compliant with the treatment scenario.
If one or more non-compliant teeth are identified, determining, depending on the updated time, one of an intermediate models, or ‘active intermediate model’, then identifying one or more models of teeth representing the noncompliant tooth or teeth, respectively, in the active intermediate model.
Deforming the active intermediate model until an updated model is obtained that is compatible with at least one of the updated images.