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 by creating formulae for mapping relative positions of landmarks between said first and second dental images and identifying corresponding points between the first and second dental images using said formulae; and the computer presenting the registered images in alternating views by overlaying the aligned first and second dental images over each other for display whereby differences between the first and second dental images are displayed in flicker as the registered images alternate views on the display.