[Three-dimensional surface reconstruction of spiral CT for teeth and clinical use in examining impacted teeth of jaws].

OBJECTIVE

To establish a new technique for three-dimensional surface reconstruction of teeth (dental surface reconstruction), and apply it to investigate impacted teeth in bone before operation.

METHODS

On the basis of three-dimensional surface reconstruction of teeth and jaws, the dental surface reconstruction is obtained with the technique of shaded surface display (SSD), making transparent bone around. This technique is applied to investigate 9 cases of supernumerary and impacted teeth.

RESULTS

Dental surface reconstruction image can present the dental surface image including crown, root, neck and root bifurcation in three-dimensional way, without presenting the image of other tissue around. In 4 cases, the abnormal configuration, labial or palatal location, and relation with dentition in anterior maxilla of 5 supernumerary were shown. In 1 case, the shape, location, eruption orientation and the angle of orthodontic distraction of 1 impacted permanent canine were displayed. In 3 cases, the shape, location, and extraction resistance of 6 impacted wisdom teeth were revealed. In 1 case, the configuration, distance to adjacent molar of 1 impacted wisdom tooth, which is a transposition tooth in maxillary sinus, were also demonstrated.

CONCLUSION

The dental surface reconstruction is a new technique to display three-dimensional surface configuration of teeth. This technique can be applied to examine impacted and supernumerary teeth before surgical and orthodontic treatment.