ABSTRACT
The dental arch post-therapeutic modification plays a significant role in relapse phenomenon. This article describes the design work of the dental arches used as a base for the study of modifications that have arisen during orthodontic treatment then during the retention stage using pre-formed arch wires. ARCAD'Image software tries to design the patients dental arches by submitting a linear regression mathematical design on some characteristic landmarks of a photograph of the buccal impression. The designed dental arch can then be considered as being the closest/nearest to the patients morphology. This model enables the practitioner to bend the arch wire and is used as a base for the study of arch shape modifications. Our study shows that the term "relapse" appears to be used excessively; it would be more matter of evolution due to changes in neuro-muscular balance along with facial aging.
