COMPUTER-BASED IDENTIFICATION OF LANDMARKS IN CEPHALOGRAMS

Abstract

The aim of the project was to detect and measure some craniofacial landmarks for use by the orthodontist in diagnosis and treatment planning. Altogether eight landmarks were to be detected. They were the sella, nasion, pogonion, menton, incisor superious, apicale superious, incisor inferious and apicale inferious. The original image was divided into smaller sub-images that contained the landmarks of interest, which were then analyzed accordingly.

A windows-based application software was built. The user needs only to highlight the region containing the sella and all other landmarks are detected automatically. Acceptance tests were performed on detected landmarks to ensure that the results obtained were valid. The results of landmark identification were classified as pass, fail or unsure. The algorithm successfully detected 70% of the sella, 70% of the nasion, 50% of the menton and the pogonion, and 30% of the incisor/apicale inferious/superious within the margin of error of 2 mm.