Age estimation based on Demirjian's method using third molars in individuals from Southeastern Brazil

Area of Science:

• Forensic Anthropology
• Odontology
• Radiology

Background:

• Accurate age estimation is crucial in forensic and clinical contexts.
• Third molar mineralization stages are a reliable indicator for age assessment in adolescents and young adults.
• Previous age estimation formulas may lack accuracy in specific populations.

Purpose of the Study:

• To assess the applicability of third molar mineralization stages for chronological age estimation in a Southeastern Brazilian population.
• To test a previously developed age estimation formula from a Northeastern Brazilian population.
• To develop and validate a new, population-specific age estimation formula based on third molar development.

Main Methods:

• Analysis of digital panoramic radiographs from 1570 individuals aged 7-22 years.
• Classification of third molar developmental stages (Demirjian's scale) by two independent examiners.
• Development of a new age estimation formula using multiple linear regression on 1260 radiographs and validation on 310 radiographs.

Main Results:

• A strong positive correlation (R=0.925) was observed between chronological age and third molar mineralization stages.
• The previously developed formula significantly overestimated chronological age.
• The new formula demonstrated high performance, explaining 85% of age variance (R²=0.85) with low prediction errors (MAE=1.35, RMSE=1.71).

Conclusions:

• Third molar mineralization stages are strongly correlated with chronological age in Southeastern Brazilians.
• Population-specific age estimation models are necessary due to variations in developmental timing.
• The newly developed formula offers a more accurate and reliable method for age estimation in this subpopulation, with significant forensic and clinical implications.