Volumetric Pulp Analysis of Mandibular Molars on CBCT as a Supplementary Indicator for Age-Related Dental Changes: A...

Background/Objectives: This study aimed to evaluate the relationship between CBCT-derived total pulp volume and chronological age in mandibular first molars (M1) and second molars (M2), and to explore the preliminary utility of volumetric pulp analysis as a supplementary indicator for age-related dental changes in a Turkish population sample. Methods: CBCT scans of 60 individuals (32 females, 28 males; age range: 18-48 years) were retrospectively analysed. Pulp volumes of 60 mandibular molars (32 first and 28 second molars) were segmented using a semi-automatic thresholding approach with manual correction. Spearman correlation analysis was performed to assess the relationship between pulp volume and chronological age, stratified by sex and tooth type. Following comprehensive regression diagnostics-including the Shapiro-Wilk test, Breusch-Pagan test, and Cook's distance-Huber M-estimator robust regression was selected as the primary analytical method, with OLS bootstrapped regression retained as a sensitivity analysis. Results: A statistically significant negative correlation was found between pulp volume and chronological age in both mandibular first molars (Spearman ρ = -0.554, p = 0.001) and second molars (ρ = -0.693, p < 0.001). Huber robust regression confirmed pulp volume as a significant predictor in both groups: M1 (β = -0.151, p = 0.001; Age = 33.646 - 0.151 × Volume) and M2 (β = -0.205, p < 0.001; Age = 36.833 - 0.205 × Volume). OLS sensitivity analysis yielded R² = 0.238 (SEE = ±5.978 years, n = 32) for M1 and R² = 0.499 (SEE = ±4.908 years, n = 28) for M2. No statistically significant sex differences were detected in either molar group. Conclusions: This preliminary study suggested that CBCT-derived mandibular molar pulp volumetry demonstrates a statistically significant negative association with chronological age in a predominantly young adult Turkish population.