Age estimation of skeletal remains: principal methods

Research and Reports in Forensic Medical Science Dovepress open access to scientific and medical research Review Research and Reports in Forensic Medical Science downloaded from https://www.dovepress.com/ by 88.198.20.149 on 06-May-2021 For personal use only. Open Access Full Text Article Age estimation of skeletal remains: principal methods This article was published in the following Dove Press journal: Research and Reports in Forensic Medical Science 5 February 2014 Number of times this article has been viewed Chiara Villa Niels Lynnerup Unit of Forensic Anthropology, Department of Forensic Medicine, University of Copenhagen, Copenhagen, Denmark Introduction and background Correspondence: Niels Lynnerup Unit of Forensic Anthropology, Department of Forensic Medicine, Frederik d 5´s Vej 11, DK-2100 Copenhagen, Denmark Tel +45 3532 7239 Fax +45 3532 6150 Email Identification of human remains almost always involves assessment of the age at death of the individual. While aging phenomena occur in non-bony tissues, it was for a long time osseous tissue and teeth that were at the core of most methods.1–7 This was due both to the persistence of these tissues (when most soft tissues would decompose) and the fact that age determination is much-used also in archaeological work, when excavating prehistoric and historic skeletons.3,4 In forensic cases, determining age at death and year of birth are, in all practicality, two sides of the same issue. However, since many of the most-used methods were developed also for use in archaeological anthropology, they are usually referred to as methods for determining age at death. An archaeologically recovered individual can seldom be set in an absolute chronological framework (unless, for example, by tombstones, inscriptions on coffins, coffin plates, etc). But in forensic cases, determining age at death is often translated into probable year of birth (or a range for this), as this is an item of data that may be registered, and thus lead to identification. A fundamental presupposition of most forensic anthropological methods is that the biological age of an individual more or less follows the chronological age. The chronological age is our calendar age, which we identify in years, while the biological age refers to how aging affects our bodies and how this may be observed. Generally, most age assessment methods rely on identifying certain age-related skeletal traits, then setting these traits in a system of stages or scores, which results in an estimated 3 submit your manuscript | www.dovepress.com Research and Reports in Forensic Medical Science 2014:4 3–9 Dovepress © 2014 Villa and Lynnerup. This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php http://dx.doi.org/10.2147/RRFMS.S35660 Powered by TCPDF (www.tcpdf.org) Abstract: The age of an individual is often a fundamental piece of data in connection with forensic identification of unidentified bodies. The methods most often used are based on visually determining various morphological, age-related changes in the skeleton (or teeth, although odontological methods are not reviewed in this paper). As such, these methods are all relative: ie, they do not obtain results in calendar years but estimates of the age at death, often with a rather large range. Recently, methods have been proposed for more direct ascertainment of age at death: eg, protein racemization and radiocarbon methods. The latter method, especially, may yield absolute age (year of birth), because radiocarbon activity (as measured in specific proteins in specific cells or tissues of the body) may be in equilibrium with the so-called bomb-pulse, when atmospheric radiocarbon content has changed markedly from one year to another. This review covers the basic and most often used gross morphological methods, radiologically-based methods, biochemical methods, and radiocarbon dating. Keywords: skeletal, aging, human remains Research and Reports in Forensic Medical Science downloaded from https://www.dovepress.com/ by 88.198.20.149 on 06-May-2021 For personal use only. Villa and Lynnerup age interval.2–7 However, more recently, methods that rely on biochemical analyses, as well as isotope, heavy metals, and radiocarbon analyses, have been introduced that are also applicable to other tissues (although most methods still focus on skeletal and dental tissues). In this review, the conventional morphological methods used by the forensic anthropologist will be presented. Odontological methods will be addressed elsewhere. Methods relying on macroscopic morphological features Assessing age may be done somewhat reliably when dealing with subadults, as the biological–chronological relationship is clearly reflected in the growing subadult skeleton. Thus, features associated with bone growth, such as epiphyseal closure,4–7 closure of the sphenobasilar synchondrosis,5 and, obviously, (diaphyseal) bone length4,7–9 may be used. Concerning the adult skeleton, most methods focus on the nonsynovial joints (synostoses and synchondroses), ie, joints between single bones, without a synovial membrane between (which also precludes any movement in the joint except for minor elastic bending), as seen, for example, in the sacrum and innominates. One of the first methods to be devised relies on cranial sutures. Described by Broca in 1875, it has since been tested extensively – although, with the overall finding that, even though there seems to be an age-related trend in the complete ossification of the sutures (seen as obliteration), this trend is, perhaps, more tenuous than for the other methods described below.7,10–13 It has also been difficult to develop unbiased and definite criteria for using sutures in age determination.11–14 Several standards have been proposed for tabulating sutural ossification, including those of Acsadi and Nemeskeri15 (as incorporated in their Composite method), Buikstra and Ubelaker,3 and Meindl et al.12 The latter standard, especially, which also utilizes some minor sutures of the lateral aspect of the skull, is commonly used. One benefit of Meindl et al’s method, aside from accuracy, is the documentation of the skull gained indirectly; assigning scores for ten sutural areas on the skull attests also to the preservation and completeness of the cranial vault.12 As such, this method is often recommended, although some studies seem to indicate that endocranial ossification might be more accurate (...truncated)