External validation of a country-specific model for radiographic dental age assessment of Brazilian children and adolescents.

Dental age assessment may have important clinical and forensic applications. Testing the existing methods is fundamental to promoting best clinical and forensic practices. The present study aimed to test a Brazilian country-specific model for dental age assessment in a population of Bahia State, Brazil. A total of 1009 panoramic radiographs of Brazilian individuals (n=556, 55.1% females and 453, 44.9% males) aged between 6 and 15.99 years were collected. The seven permanent left mandibular teeth from central incisor to second molar were analyzed in each radiograph. Demirjian's dental staging technique was applied followed by age estimation through Franco's dental age assessment model. Differences between chronological and estimated ages were quantified as mean error (ME), mean absolute error (MAE), and root means squared error (RMSE). The overall (sex combined) ME, MAE, RMSE were -0.51, 1.11, 1.63, respectively. For females and males separately, the error metrics were: -0.55, 1.16, 1.65 and -0.45, 1.05, 1.59, respectively. Bland-Altman plots showed narrower age limits among males, while higher discrepancies were observed for females. The analysis based on age categories showed the worst predictions between the ages of 6 and 6.99 years. The tested country-specific model was applicable to individuals aged above 7 years in the target population, being an alternative for dental age assessment.