Landmarking of cephalograms using a microcomputer system.

Landmarks, or certain characteristic reference points, on cephalograms are used as a diagnostic aid employed in treatment planning by orthodontists. This work presents an algorithm for recognizing some anatomical features and locating landmarks on lateral skull X rays (cephalograms) using digital image processing and feature recognition techniques. A cephalogram is digitized and stored in a computer memory. Prefiltering is applied to remove image noise. The bony and flesh profiles of jaw and front face are traced. Using these profiles the algorithm locates 17 points on the image, some on bony features and others on soft tissue. To locate these points, edge-enhancement, thresholding, and edge-detection techniques are applied. The algorithm can be run on an IBM compatible microcomputer.