Objective To discuss the clinical value of spiral CT in locating impacted teeth. Methods 23 cases with impacted teeth were examined with spiral CT scanning, which was to demonstrate the shape and location of impacted teeth and their relationship with neighbor teeth by means of three dimensional construction including multiplanar reconstruction（MPR）, surface shaded display（SSD） and volume rendering（VR）. Results There were 28 impacted teeth in 23 patients. The number of impacted teeth, shape, labial or palatal lacation, eruption orientation and their relationship to adjacent teeth could be clearly demonstrate on the reconstructed three dimensional images. Conclusion The combination of CT axial images with different reconstructions is an accurate and effective method to examine impacted teeth.
