Willems I VS Willems II: A comparative study of accuracy in 5-15 year old Indian children

Studies testing the Willems method of age estimation with gender-specific scores on different population groups have reported consistently more accurate results over other methods. Not enough is known about the validity of Willems non-gender specific scores.

The present study aimed to compare the accuracy of the Willems I (gender-specific scores) and Willems II methods (non-gender-specific scores) in the age estimation of 5-15 year-old Indian children.

In this cross-sectional observational study, the Willems I and II methods were tested and compared for accuracy in estimating the age of 1200 Indian children aged 5-15 years.

The mean differences between dental age calculated by the Willems I method and chronological age were +0.09±0.80 years, +0.08±0.80 years and +0.09±0.80 years for boys, girls and the total sample, respectively. With the Willems II method, the values were -0.06±0.80 years, +0.11±0.79 years and +0.01±0.80 years for boys, girls and the total sample, respectively. Both methods did not show any statistically significant differences between dental and chronological ages for either gender or the total sample (p>0.05).

The Willems I method was more accurate in predicting age of boys, while the Willems II method was more accurate in girls in the present study, but not significantly so. Both methods are appropriate for use in this population.