1. A computer-implemented method for identifying and/or presenting changes in dental images over time, comprising the steps of: a user selecting using the computer a first dental image of a dental region taken at a first point in time and a second dental image of said dental region taken at a second point in time, wherein said second dental image is captured from a similar perspective as said first dental image; adjusting using the computer at least one of said first and second dental images so as to compensate for differences in perspective, size, and rotation to thereby register the first and second digital images to each other; and the computer presenting the registered images in alternating views.