Patent ID: 7077647

Claim:
A method for determining progress of a dental treatment, the method comprising: providing an initial digital model of a set of dental objects; determining planned positions for the set of dental objects; providing a subsequent digital model of the set of dental objects in their moved positions after at least some of them have been moved by the dental treatment; individually matching each of the dental objects in the subsequent digital model with a dental object in the initial digital model to determine corresponding dental objects, the matching comprising; identifying one or more reference points on each set of corresponding dental objects in the initial and subsequent digital models: approximately matching each set of corresponding dental objects by approximately aligning corresponding reference points on corresponding dental objects; and matching each set of corresponding dental objects more closely by iteratively minimizing error between corresponding reference points on corresponding dental objects; matching the subsequent digital model as a whole with the initial digital model; and calculating one or more positional differences between the moved and planned positions of at least some of the corresponding dental objects.