Radiographic root pulp visibility of the mandibular left second molar as an indicator of legal adulthood (≥ 18 Years): a panoramic study

This study aimed to evaluate the diagnostic performance of mandibular left second molar root pulp visibility (RPV) for legal age classification (≥ 18 years) using panoramic radiographs. A total of 983 orthopantomograms (492 males, 491 females) were retrospectively analyzed. Root pulp visibility was classified according to the staging system described by Olze et al. Diagnostic performance measures, logistic regression analysis, and receiver operating characteristic (ROC) analysis were performed. A p-value < 0.05 was considered statistically significant. A statistically significant association was observed between pulp stage and legal age classification (p < 0.001). Logistic regression analysis demonstrated a stage-dependent increase in the odds of being classified as ≥ 18 years, with Stage 2 and Stage 3 showing strong predictive effects (OR = 6.04 and OR = 19.13, respectively). Diagnostic performance analysis indicated that Stage ≥ 2 demonstrated high specificity (0.94). ROC analysis revealed moderate discriminatory performance (AUC = 0.676; 95% CI: 0.647-0.705). Mandibular second molar root pulp visibility may serve as a useful radiographic marker for legal age threshold assessment, particularly at higher pulp stages.