Age estimation using the pulp-to-tooth volume ratio of canines based on cone-beam computed tomography: a systematic review and meta-analysis

The continuous deposition of secondary dentin as age advances leads to a pulp chamber reduction, which has enabled the development of methods for dental age estimation. The aim of this systematic review and meta-analysis was to assess the reliability of the pulp-to-tooth volume ratio of canines, measured using cone-beam computed tomography (CBCT), as an indicator for chronological age estimation. After searching for and selecting studies according to predefined eligibility criteria, data were extracted and organized into spreadsheets using Microsoft Excel© software (Microsoft Corp., Redmond, WA, USA). Risk of bias was assessed using the checklist proposed by the Joanna Briggs Institute, and quantitative analysis was conducted using RStudio software (R Foundation, Vienna, Austria). Ten studies were included and classified as having a low risk of bias. Nine studies were included in the meta-analysis, totaling 15 correlation coefficients between the pulp-to-tooth ratio and chronological age. Substantial heterogeneity was observed (I2 = 98.8%), along with a moderate negative correlation (r = -0.59). After the removal of outliers, heterogeneity was reduced (I2 = 70.4%) and the correlation increased (r = -0.70). The pulp-to-tooth volume ratio obtained from CBCT examinations of canines may be used for age estimation in individuals with complete dental development. However, in light of the findings, this parameter should be applied with caution.