Impaction and Mineralization Status of the Mandibular Third Molar: A Retrospective Study

Chronological age estimation is used in legal contexts to determine the transition between minor and adult status, with the third molar (3M) being a primary biological indicator. This retrospective study aimed to analyze the relationship between the topographic position of impacted mandibular 3Ms and their mineralization stages, evaluating how specific angulations influence developmental chronology. Using a database of digital panoramic radiographs from 731 individuals aged 16 to 20 years, 3M development was assessed via Demirjian’s stages and impaction was classified by Winter’s angulation. Results demonstrated that non-impacted teeth consistently show more advanced mineralization compared to impacted teeth, with an average maturational delay of 0.35 stages in the latter. Furthermore, horizontal impactions exhibited significantly accelerated maturation, with 88.2% reaching the terminal Stage H, while mesioangular impactions were associated with marked developmental delay and were significantly underrepresented in Stage H. In conclusion, both eruption status and topographic orientation significantly modulate 3M mineralization. These findings suggest that applying uniform reference standards without considering tooth angulation may cause systematic bias in forensic age estimation, potentially leading to the underestimation or overestimation of age around critical legal thresholds.