An In Vitro Evaluation of Pulp-tooth Volume Ratio in Primary and Mixed Dentition Using Micro-CT Scans for Age Estimation

Despite the increasing use of CBCT, its spatial resolution remains inferior to that of micro-computed tomography (micro-CT).Micro-CT offers ultrahigh-resolution imaging, enabling precise 3D reconstruction and accurate segmentation of dental hard tissues and pulp space without destructive sectioning.Microfocus X-ray CT has been shown to provide superior accuracy in pulp volume measurement compared to conventional imaging techniques, particularly in teeth with complex internal morphology.5 However, existing micro-CT-based age estimation studies are limited in number and are predominantly focused on permanent teeth in adult populations. IntroductIonDental age estimation plays a pivotal role in pediatric dentistry, orthodontics, forensic science, and legal medicine, particularly in children, where chronological age documentation may be incomplete or unreliable.Teeth are considered one of the most stable biological structures in the human body and undergo predictable age-related changes, making them reliable indicators for age estimation.Among these changes, continuous deposition of secondary dentin leads to a gradual reduction in pulp size, resulting in a measurable decrease in the pulp-tooth volume ratio (P/TVR) over time.This biological phenomenon has been widely utilized as a nondestructive parameter for dental age estimation. 1 Conventional dental age estimation techniques have largely relied on two-dimensional (2D) radiographic methods; however, these approaches are limited by image distortion, superimposition, and inaccuracies in volumetric assessment.The advent of three-dimensional (3D) imaging modalities such as cone-beam computed tomography (CBCT) has significantly improved the accuracy of pulp and tooth volume measurements and strengthened the correlation between P/TVR and chronological age.1,2 Systematic reviews and meta-analyses have further validated pulp volume quantification as a reliable method for age estimation, while also highlighting methodological variability and the need for standardized imaging protocols.3,