Age Estimation by Pulp/Tooth Ratio Using Digital Orthopantomograms – A Preliminary Retrospective Study

Introduction: Age estimation of both the living and the dead is one of the most important sub disciplines of forensic sciences and is of significance in medicolegal issues. Teeth can also be used to determine the age of a living individual in association with crimes and other purposes. Radiographic assessment of age is a simple, non-invasive and reproducible method that can be employed on the living and unknown dead. After root completion, secondary dentine is deposited throughout one's life, reducing the pulp chamber. The pulp chamber reduces as the chronological age advances and is least influenced by other environmental factors.
Aim: The study aimed to evaluate reliability of dental radiographic age assessment for adults using pulp /tooth ratio in digital panoramic radiographs.
Materials and methods: Digital orthopantomograms (OPG) of 20 individuals (10 males and 10 females) were taken from the digital archives (October 2019) of the Department of Oral Medicine and Radiology of our college. Good quality radiographs of patients above 18 years and up to 70 years of age were included. The reference teeth were 36, 37, 46 and 47. The measurements were performed on the JPEG images of selected digital OPGs. The measurements were done using GNU Image Manipulation Program (GIMP) [2.10.22] and were recorded by a single observer. Crown Root Trunk Height (CRTH) was calculated by measuring the distance between the central fossa and the highest point on root furcation. Pulp Chamber Height (PCH) was calculated, which is the distance between the roof and floor of the pulp of the pulp chamber. Pulp Chamber Crown Root Trunk Height Ratio (PCTHR) was obtained as the ratio of PCH to CRTH. Chronological age of the subject was recorded based on his/ her date of birth. All data were entered and analysed using SPSS (Statistical Package for Social Science) v11.5TM. The age estimation formula was derived by simple linear regression analysis.
Results: The Pearson’s correlation coefficient test shows that the PCTHR value of all the teeth except 36 are significantly correlated with the age of the study population. (As age increases, there is a significant reduction in PCTHR of teeth 37, 46, and 47 in the study). R2 value denotes the variance in the age as explained by the PCTHR value of tooth 47 in the study. It means that 66.2% of change in age is explained by the change in the PCTHR value of tooth 47 in the study. The Pearson’s correlation coefficient test shows that the predicted age and actual age are strongly correlated with each other (r=0.813).
Conclusion: This study showed that PCTHR has a negative correlation with chronological age. There was a statistically significant correlation observed between chronological and calculated age by this method. Validation with a larger population of wider geographic and ethnic diversity is recommended to generalize the results of this study. The limitations of the study include a small sample size and a single observer recording the measurements.