Optimization of panoramic radiographic dose for third molar dental age assessment

This study aimed to assess the influence of reduced exposure parameters on the reproducibility of two radiographic dental age assessment methods in panoramic radiographs: the staging system (GHK) proposed by Gleiser and Hunt (1955) modified by Köhler et al. (1994) and the metric method by Cameriere et al. (2008) (I3M). Five phantoms were prepared using dry human skulls and subjected to three different radiographic image acquisition protocols with variations in peak kilovoltage (kVp) and tube current (mA), resulting in different absorbed dose levels: Protocol 1 (70 kVp, 12.5 mA), Protocol 2 (66 kVp, 8 mA), and Protocol 3 (66 kVp, 3.2 mA). A total of 57 cropped digital images of third molars were obtained and evaluated by 10 trained examiners at two different times. Intra-observer agreement was assessed using Fleiss' weighted Kappa coefficient for the GHK method and the intraclass correlation coefficient (ICC) for I3M. The results showed substantial to good agreement for both methods, with high mean kappa and ICC values and no significant statistical differences among the protocols. In the dichotomous classification of legal adulthood (< 18 or ≥ 18 years) using the I3M, the lowest-dose protocol performed equivalently to the standard protocol. Considering the current study settings, reducing exposure parameters did not compromise the reproducibility of radiographic third molar analysis for dental age assessment methods. This outcome supports the use of low-dose image acquisition protocols as a potentially viable and (bio)ethical alternatives in forensic contexts.