The application of computerized tomography (CT) to the dental ageing of children and adolescents

Following a mass disaster, the aim of the Disaster Victim Identification process is to establish the identity of the victims. The ageing screening process on victims in Victoria may now be complemented with the use of computerized tomography (CT), where previously any dental ageing analysis was performed using conventional radiographs. The aim of this study was to assess the accuracy of age estimation using the dental ageing method proposed by Moorrees, Fanning and Hunt (MFH) using CT images. Intra- and inter-rater variability between two raters, one experienced and one inexperienced, was also assessed.

The two raters were blinded to the ages of 96 deceased Australian children aged up to 15 years. Using three-dimensional (3D) shaded surface displays (SSD) and reformatted CT images, the age was first estimated based on prior experience alone, followed at a later date by the age estimation utilizing the MFH method. These estimates were then compared to the known chronological age. The results were statistically analyzed in a one-sample t-test, using the mean log-ratio of the estimated age to the chronological age.

Our findings show that the experienced rater was more accurate in age estimation than the less experienced when using prior experience (p<0.0001). The use of reformatted CT images to perform an ageing estimate using the MFH method was found to systematically underestimate the chronological age by 10% by both raters (p=0.784). There was no significant difference between the two raters. Intra-rater reliability was high (p=0.135).

CT can provide accurate estimates of dental ages. Prior experience with dental ageing and/or CT improves the accuracy. However, with the use of validated ageing charts, inexperienced raters can also achieve accurate age estimates using CT images.