Written by Jeremy Graham

  • Thesis Title: The Application of CT Imaging to the Dental Ageing of Children and Adolescents
  • Author: Jeremy Graham
  • Submitted as a requirement for: Master of Philosophy
  • Date: 2008

Abstract: Dental ageing can be the first step in the identification of young people especially following a mass disaster.
In the past, radiographs were traditionally used to perform the analysis. With the advent of computed tomographical (CT) technology in forensic medicine, the need for assessment of this modality for dental ageing is necessary. The aims of this study were 1. to compare ageing estimates using five ageing methods between CT and X-Ray and to determine inter- and intra-rater variability of these methods and 2. to utilise one of the five methods to estimate dental ages among 96 retrospectively collected cases at The Victorian Institute of Forensic Medicine and compare results with the real ages.

The CT images of 10 children were retrospectively analysed using CT and X-Ray by three odontologists blinded to the real ages of the cases. Estimated ages were evaluated using five ageing methods. A General Linear Model was fitted to compare methods, imaging modalities, raters and cases.

The main study involved dental ageing using CT images only using the method of Moorrees, Fanning and Hunt (MFH). This ageing estimate was complemented with an additional ageing estimate at the time of the image enhancement, based on the overall appearance of the CT images, without resorting to any specific ageing technique. CT based and experiential ageing estimates were compared with real ages upon completion of the study using the log(ratio estimated age/real age).

Results in the pilot study showed that CT was as accurate as X-rays. Inter- and intra-rater reliability was high. The results of the Main Study showed that the MFH method underestimated the age of the children by approximately 10% (95% CI: 83.9% to 98.4%) (p=0.019). The experiential estimate was found to be more accurate, with the rater assessing age within 2% of the actual age (95% CI: 92.5% to 112%) (p=0.719).

The study has shown that dental ageing based on CT imaging is as accurate as X-Ray. Both an established method or experience can yield realistic estimates of deceased children’s ages.