A validation study of the Stoyanova et al. method (2017) for age-at-death estimation quantifying the 3D pubic symphyseal surface of adult males of European populations

Abstract

The age-at-death estimation thresholds have recently been shifted towards a more objective assessment of the aging process. Such a non-subjective approach offers quantitative methods of age estimation; for instance, the method relating to the surfaces of pubic symphyses of males published by Stoyanova et al. (J Forensic Sci 62:1434-1444, 2017). A validation study was conducted to test the method performance in European samples. The sample consisted of 96 meshes of pubic symphyses of male individuals (known sex and age) that came from four different samples (two Portuguese collections, one Swiss, and one Crete). Stoyanova's method based on five regression models (three univariate and two multivariate models) performed worse in our sample, but only when the whole sample (without age limitation) was included. A sample limited to individuals under 40 years of age achieved better results in our study. The best results were reached through the thin plate spline algorithm (TPS/BE) with a root mean square error of 5.93 years and inaccuracy of 4.47 years. Generally, the multivariate regression models did not contribute to better age estimation. In our sample in all age categories, age was systematically underestimated. The quantitative method tested in this study works best for individuals under 40 years of age and provides a suitable basis for further research.

The computational age-at-death estimation from 3D surface models of the adult pubic symphysis using data mining methods

“…It should also be noted that the models of Stoyanova are restricted to male individuals only. 2018) also included male individuals only 27,57 , while Joubert et al 55 , Johnson and Bethard 54 and the present study incorporated both sexes. As the results of all the validation studies are similar, the inclusion of female individuals did not appear to affect the performance of the method.…”

“…The most prominent computational approach for estimating adult age based on the analysis of surface changes in 3D models is the approach of Stoyanova et al (2017) 25 . We applied their ve models on our dataset and found signi cant discrepancies between the MAE (and RMSE and MBE as well) presented by Another reason for such poor results when the models of Stoyanova were applied to our or other validation datasets could partially be seen in the population speci city 27,55,56 and different aging rates between populations, since their models were proposed solely on American samples. Several studies reported population speci city when evaluating the performance of the traditional Suchey-Brooks method (e.g.…”

“…Since different types of scanning devices and technologies (laser and structured light) have different resolutions and capture different levels of detail on the scanned surface (e.g. Structured Light Technology, which was used in this and our previous studies 27,57 , is known for providing higher resolution), it could be assumed that this will also affect subsequent analyses (e.g. results of the approach of Stoyanova et al).…”

“…However, their approach is far from being perfect since, for example, it is not able to distinguish younger from older individuals whose pubic symphyseal surfaces are both rugged but in different ways (irregular in older individuals). This results in the strong underestimation of not only older individuals 25 but of the whole sample 27 . Recently, Bravo Morante et al (2021) presented a new quantitative method based on the bandpass ltering of partial warp bending energy 28 , which is a modi cation of one of the shape scores (bending energy) applied in a previous study 25 .…”

Impact of 3D surface scanning protocols on the Os coxae digital data: Implications for sex and age-at-death assessment

“…The forAge software is one of the few age estimation approaches using mathematical quantification of bone surface that has been published so far. Repeatability of the method was tested with excellent results [60] and its use is suitable for individuals under 40 years of age [61].…”