Estimate the Age of Han Adult Based on the Pulp Chamber Volume and Pulp Dentinal Index of Right First Molars Using Oral and Maxillofacial CBCT.

OBJECTIVES: To explore the correlation between the actual age and the pulp chamber volume (PCV) and pulp dentinal index (PDI) of the right first molars based on cone beam computed tomography (CBCT) technology, and to construct an accurate and convenient model for age estimation. METHODS: CBCT image data of 1 857 Han adults (883 males and 974 females) from the Department of Stomatology, Affiliated Hospital of North Sichuan Medical College were collected. The data were divided into training and validation sets at a ratio of 8ratio2. A total of 1 485 training samples were used to construct the age estimation model, and 372 samples were used to validate the accuracy of the model. The Mimics 21.0 software was used to measure the PCV and calculate the PDI of the right first molars. Their correlations with age and the differences between different sexes and tooth positions were analyzed. RESULTS: Both the PCV and the PDI of the first molars showed strong negative correlations with the actual age (r values ranged from 0.82 to 0.89). The differences in PCV and PDI between different sexes and tooth positions were statistically significant (P<0.05). The age estimation model based on PDI was superior to that based on PCV. The model based on the PDI values of the two right first molars (y=73.72-44.15 x(3)-28.27 x(4), where x(3) and x(4) are the PDI values of the right maxillary and mandibular first molars, respectively) was the best, with the R(2) of 0.79 and the mean absolute error of 4.90 years. CONCLUSIONS: Both PCV and PDI of the first molars are effective indicators for age estimation. The age estimation model based on the PDI is more convenient and accurate than that based on the PCV, providing a more effective method for age estimation in forensic practice.