[The micro-anatomy and clinical significance of the apical foramen in 1,282 permanent teeth].

To study the shape and size of the apical foramen of permanent teeth and their relations, we observed 1,282 permanent teeth. The teeth were photographed by XTL-2 photstero microscope. The rule of its shape and its clinical significance were discussed. In the 1,282 teeth, the round and oralshaped accounted for 94.77% (1,215/1,282), indicating that the morphological appearance of the apical foramen is inconsisted with that of vessels or/and nerves in the tissues.