A systematic review and meta-analysis of the fully formed wisdom tooth as a radiological marker of adulthood

Assessment of third molar development on dental radiograms is one of the most commonly used methods of forensic age estimation. Despite widespread use and numerous studies, there is a paucity of aggregated data on how well a fully mature third molar identifies adulthood (> 18 years), the most important threshold in a medicolegal context. Therefore, a systematic review and meta-analysis was conducted. A total of 1229 studies were screened, and 82 studies were assessed for inclusion. Twenty-four studies, with a pooled cohort of 19,690 individuals, presented true positive (TP), true negative (TN), false positive (FP), and false negative (FN) outcomes, enabling meta-analysis. The outcomes were based on using the third molar in the fully mature stage as a diagnostic test to indicate age 18 years or above. The false positive rate (fall-out/1-specificity) was 3.1% (95% CI 2.1–4.6%), and the true positive rate (recall/sensitivity) was 51% (95% CI 44–58%). Diagnostic accuracy was 71%. These findings, while reassuring in terms of the low false positive rate, highlight the need for complementary age estimation methods to avoid a significant number of false negatives.