Apical foraminal openings in human teeth. Number and location

One hundred forty extracted permanent human teeth were prepared for examination with a scanning electron microscope to determine the number of foramina, their distances from the apices, and their locations. In most of the specimens, the root canals deviated to one side and ended short of the apices. Some specimens showed interradicular openings; others had configurations on the top of the apices that were similar to the crest on a helmet.