Computer-aided identification of the root apex in dental radiographs

A digital image analysis method has been developed to retrieve information about the location of a root apex in a dental radiograph. This method was tested on a sample of 262 roots. The distance between the location of the apex obtained from the system and the location obtained from five expert observers was less than 2 millimeters in 78.2% of the cases and less than 1 mm in 49.2%. The method was based on the assumption that the shape of a root in the image was correctly identified through a shape analysis procedure. When the results were corrected for incorrect shape identification, the distance between the boundary of the root in the image and the boundary identified by the system was less than 2 millimeters in 92.7% of the cases and less than 1 millimeter in 74.0%. It is concluded that this method is promising in its capacity to add relevant spatial information to imaging systems, aimed at the analysis of the periapical region.