The Brazilian (FRANCO) method for dental age estimation: Willems' model revisited.

OBJECTIVES: This study aimed (I) to test the Willems' dental age estimation method in different geographic samples of the Brazilian population, and (II) to propose a new model combining the geographic samples in a single reference table of Brazilian maturity scores. MATERIALS AND METHODS: The sample consisted of 5017 panoramic radiographs of Brazilian males (n = 2443) and females (n = 2574) between 6 and 15.99 years (mean age = 10.99 ± 2.76 years). The radiographs were collected from the Southeastern (SE) (n = 2920), Central-Western (CW) (n = 1176), and Southern (SO) (n = 921) geographic regions. Demirjian's technique was applied followed by Willems' method and the proposed Brazilian model. RESULTS: Willems' method led to mean absolute errors (MAE) of 0.79 and 0.81 years for males and females, respectively. Root mean squared errors (RMSE) were 1.01 and 1.03 years, respectively. The Brazilian model led to MAE of 0.72 and 0.74 years for males and females, respectively, and RMSE of 0.93 years for both sexes. The MAE was reduced in 70% of the age categories. Differences between regions were statistically (p < 0.05) but not clinically significant. CONCLUSION: The new model based on a combined population had an enhanced performance compared to Willems' model and led to reference outcomes for Brazilians. CLINICAL RELEVANCE: Assessing patients' biological development by means of dental analysis is relevant to plan orthopedic treatments and follow up. Having a combined-region statistic model for dental age estimation of Brazilian children contributes to optimal age estimation practices.

Radiographic dental age estimation applying and comparing Demirjian's seven (1973) and four (1976) teeth methods.

To apply Demirjian's seven (1973, D7) and four (1976, D4) teeth methods in a sample of Brazilian children and compare their performances for age estimation. Panoramic radiographs of 1200 children (600 females and 600 males) were collected from Southeast Brazil. The children were equally distributed (n = 60 females and 60 males) between age intervals of 1 year between 6 and 15.9 (mean age = 10.9; standard deviation [SD]: 2.9) years. D7 and D4 dental age estimation methods were applied by two observers and were compared based on their error rates (error = estimated age-chronological age). Both methods overestimated the chronological age (p < 0.0001). D7 led to overestimations of 0.71 (p < 0.0001) in females and 0.83 (p < 0.0001) in males, while the overestimations with D4 were 0.14 (p = 0.0067) and 0.73 (p < 0.0001) for females and males, respectively. The mean age estimated by D7 was 11.7 (SD: 3.1) years, while for D4, it was 11.3 (SD: 3.3) years. Intra- and interobserver agreement was ≥ 0.98. D4 optimized the performance of radiographic dental age estimation compared to D7. Improvements were reflected in the total sample and separately for female and male children from Southeast Brazil.