Multi-factorial age estimation: A Bayesian approach combining dental and skeletal magnetic resonance imaging

Abstract

To study age estimation performance of combined magnetic resonance imaging (MRI) data of all four third molars, the left wrist and both clavicles in a reference population of females and males. To study the value of adding anthropometric and sexual maturation data.Materials and methods: Three Tesla MRI of the three anatomical sites was prospectively conducted from March 2012 to May 2017 in 14-to 26-year-old healthy Caucasian volunteers (160 females, 138 males). Development was assessed by allocating stages, anthropometric measurements were taken, and self-reported sexual maturation data were collected. All data was incorporated in a continuationratio model to estimate age, applying Bayes' rule to calculate point and interval predictions. Two performance aspects were studied: (1) accuracy and uncertainty of the point prediction, and (2) diagnostic ability to discern minors from adults (≥ 18 years).Results: Combining information from different anatomical sites decreased the mean absolute error (MAE) compared to incorporating only one site (P < 0.0001). By contrast, adding anthropometric and sexual maturation data did not further improve MAE (P = 0.11). In females, combining all three anatomical sites rendered a MAE equal to 1.41 years, a mean width of the 95% prediction intervals of 5.91 years, 93% correctly classified adults and 91% correctly classified minors. In males, the corresponding results were 1.36 years, 5.49 years, 94%, and 90%, respectively. Conclusion:All aspects of age estimation improve when multi-factorial MRI data of the three anatomical sites are incorporated. Anthropometric and sexual maturation data do not seem to add relevant information.

Dental and Skeletal Imaging in Forensic Age Estimation: Disparities in Current Approaches and the Continuing Search for Optimization

“…Experts advocate reporting a point prediction of age (i.e., the most likely age), together with the minimum age 7 or an uncertainty interval (prediction interval). [19][20][21]28,29 Additionally, some experts advocate reporting the probability of adulthood (i. e., 18 years in most countries). 19,28,30 Recommendations of the international Study Group on Forensic Age Diagnostics (Arbeitsgemeinschaft für Forensische Altersdiagnostik [AGFAD]) state that in the case of adolescents and young adults, development of the third molars, the left hand/wrist, and the sternal ends of both clavicles (later on referred to as the AGFAD triad) should be assessed.…”

“…This assumption was supported by some authors 21,57 but rejected by others. 19,20,28 Applying BioAlder to the case examples in ►Figs. 1-2 to 3 renders the results displayed in ►Table 1.…”

“…They reported the tables for SSA studies, 14,64,65 as well as for their MFA study. 20 Furthermore, in SSA studies, the applicability of known staging techniques for radiographs and CT were evaluated for MRI. Regarding third molars, the authors proposed an MRI-specific staging technique because the cementoenamel junction cannot be defined unambiguously on MRI.…”

“…The major limitation of the currently available MRI MFA studies is their relatively small study population. To date, only two suitable MFA studies have been published, Stern et al 24 and De Tobel et al 20 The first study included 322 males between 13 and 25 years of age; the second study included 138 males and 160 females between 14 and 26 years of age. By contrast, MRI SSA studies included larger study populations up to 496 males 67 and 623 females.…”

“…7,18 Unfortunately, reports on how to combine this information appropriately remain scarce. [19][20][21][22][23][24] Furthermore, some countries do not allow the use of medical imaging for forensic age estimation in the living. 25 Although studies on alternative approaches that do not use medical images are starting to be published, they remain unvalidated.…”