[The preliminary study on creating the differential templates of the skeletal profiles for Shanghainese with normal occlusion in early permanent dentition].

OBJECTIVE

To establish the differential templates of the skeletal profiles for Shanghainese with normal occlusion in early permanent dentition.

METHODS

71 lateral cephalometric radiographs of subjects with normal occlusion in early permanent dentition, aged from 11 - 15 years (37 females and 34 males) were traced. 23 skeletal landmarks were identified on the tracings, which afterwards were scanned on the computer. An x-y coordinate system was established: the tracing superimposed on sella rotated 7 degrees down from the sella-nasion line as the x axis and the vertical line through sella perpendicular to the x axis as the y axis. A special length/depth ratio was designed. The length/depth ratio of each graph were calculated. Steiner analysis was applied to check the difference between genders.

RESULTS

There was no difference between genders. The tracings were divided into three categories: short face, normal face and long face according to the mean and standard deviation of the ratio. The three types of tracings were superimposed on the x axis with sella registered. Three templates were created.

CONCLUSIONS

The differences were apparent when the three templates were superimposed.