Authors: Slowey RR.
Title: Radiographic aids in the detection of extra root canals.
Journal: Oral Surg Oral Med Oral Pathol
Date: May 1974
Citation: 37(5):762-72
Category: Radiology and Imaging
Evidence-based Ranking: 4
Purpose/Objective: This is an article that reviews the detection of extra root canals through the use of radiographic aids.

Discussion: 1. In single-rooted teeth with 2 canals, a straight on view will frequently show a sharp change in density in the root canal space. This indicates that a broad pulp chamber has split into 2 distinct finer canals. 2. With a file in 1 canal, a second canal in close proximity can be seen as a dark shadow in the coronal third of the root. This dark shadow usually runs for only a short distance along the file before becoming obscured. This is usually seen in MB canals that have an MB2. 3. Also, extra canals should be looked for in the coronal third of the root because they are at their largest diameter in this area, as well as being most widely separated from one another. The majority of these join into either a Y or a V configuration, but some continue as completely separate canals with their own separate apical openings. 4. When the radiograph reveals that the root canal space is not in the center of the root, one should be suspicious of an extra canal. If the canal appears to be located far to one side of the root, there is a good possibility that 2 fine canals are present rather than one larger canal.

ReviewerÂ’s comments: A good article that describes the various ways radiographs can help in detecting extra root canals. It discusses a variety of radiographic clues pointing to several anatomic variations.