Applicability of different mixed dentition analysis in Lucknow population

The aim of this study was to test the reliability of Moyer's and Tanaka-Johnston method of mixed dentition analysis among Lucknow population and also derive a linear regression equation that would predict sum of mesiodistal widths of upper and lower canines and premolars for both sexes.

Moyer's and Tanaka-Johnston mixed dentition space analysis were developed from a sample of North European descent children. Hence, it becomes questionable when applied to individuals with different ethnic origin.

Actual mesiodistal widths of permanent upper and lower incisors, canines, and premolars were recorded on 100 dental casts for both sexes using digital Vernier caliper nearest of 0.02 mm. Predicted values of mesiodistal widths of permanent upper and lower canines and premolars were obtained using Moyer's probability analysis at the 75th percentile and Tanaka-Johnston method. Both actual and predicted values for both sexes were put to statistical evaluation using student "t" test and unpaired "t" test.

Differences between the actual and predicted values of upper and lower permanent canines and premolars were statistically significant in both sexes (P < 0.05) for both Moyer's and Tanaka-Johnston mixed dentition analysis. Four linear regression, equations were developed for both sexes to predict mesiodistal widths of erupting upper and lower permanent canines and premolars using the lower incisors. No significant difference was observed when the regression equations were applied.

Predictions from linear regression equations matched well with the data obtained from the samples of the present study for both males and females of Lucknow population.