Browsing by Author "Gosset, Didier"
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- Automated age‐at‐death estimation by cementochronology: Essential application or additional complication?Publication . Bertrand, Benoit; Vercauteren, Martine; Cunha, E; Bécart, Anne; Gosset, Didier; Hédouin, ValeryIt has been repeatedly acknowledged that age-at-death estimation based on dentalcementum represents a partial and time-consuming method that hinders adoptionof this histological approach. User-friendly micrograph analysis represents a grow-ing request of cementochronology. This article evaluates the feasibility of using amodule to accurately quantify cementum deposits and compares the module's per-formance to that of a human expert. On a dental collection (n=200) of known-ageindividuals, precision and accuracy of estimates performed by a developed pro-gram (101 count/tooth;n=20,200 counts) were compared to counts performedmanually (5 counts/tooth;n=975 counts). Reliability of the software and agree-ment between the two approaches were assessed byintraclass correlation coeffi-cient and Bland Altman analysis. The automated module produced reliable andreproducible counts with a higher global precision than the human expert. Althoughthe software is slightly more precise, it shows higher sensitivity to taphonomic dam-ages and does not avoid the trajectory effect described for age-at-death estimationin adults. Likewise, for human counts, global accuracy is acceptable, but underestima-tions increase with age. The quantification of the agreement between the twoapproaches shows a minor bias, and 94% of individuals fall within the intervals ofagreement. Automation gives an impression of objectivity even though the region ofinterest, profile position and parameters are defined manually. The automated systemmay represent a time-saving module that can allow an increase in sample size, whichis particularly stimulating for population-based studies.
- The off-season of dental cementum investigations. A critical appraisal of season-of-death prediction in medico-legal investigationsPublication . Benoit Bertrand; Kaddoura, Ahmad; Cunha, Eugénia; Bécart, Anne; Gosset, Didier; Hédouin, Valery; Marques, CarinaIt has been suggested that death seasonality could be estimated based on the dark/ bright appearance of the outermost dental cementum deposit. The few existing studies show variable accuracy rates. The question whether estimating season-of-death based on dental cementum represents a realistic and achievable goal can arise. This work, based on a softwareassisted procedure and direct human observation, aims to critically evaluate the applicability of dental cementum to estimate the season-of-death in forensic anthropology. The sample consists of 20 canines from individuals belonging to the 21st century Identified Skeletal Collection, University of Coimbra, Portugal, and with documented biodemographic data. Fifty percent of the individuals died during the summer and 50% during the winter. Five non-decalcified 100 mm cross-sections per tooth were prepared, using a standardized protocol. Images of the region of interest, with the acellular cementum, were captured, and imported into FIJI/ImageJ software. Performance of the season-of-death predictions was very low, with 50% accuracy, score of 0.0000 for Matthews Correlation Coefficient, and F1-score of 61.5% for Summer and 28.6% for Winter, were obtained for the observer assessment. For the software model, performance was equally poor, with 52.6% accuracy, score of 0.0272 for Matthews Correlation Coefficient, and F1-score of 30.8% for Summer and 64.0% for Winter. This work is of relevance to the forensic science community by demonstrating the prospects and limitations of dental cementum as a method for estimating seasonality of death.