Abstract
This study aimed to validate the Willems model in a southern Saudi Arabian sample to develop and validate an age estimation model specific for the southern Saudi Arabian population and compare both models' age estimation performance. This cross-sectional study involved retrospective evaluation of orthopantomographs of 1206 children (658 males, 548 females) aged four to fourteen years. Initially, the Willems model was validated on the pooled sample. Next, this sample was split to develop a new Saudi-specific model using Willem's approach. The age estimation performance of both models was compared. Differences between chronological age (CA) and estimated dental age (EDA) were calculated and expressed in mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). The ME for the verified Willems model was 0.391 ± 1.479 years, whilst for the Saudi-specific model, it was 0.131 years ± 1.606 years. The difference in ME, MAE, and RMSE between the two models was 0.259, −0.113, and −0.082 years, respectively, and statistically significant (p < 0.05). However, clinically, these differences are trivial. Both the Willems model and the Saudi-specific model were similar in estimating CA. The use of the Willems model is recommended for estimating CA in the southern Saudi population.