Benchmark
Accurate age estimation of skeletal remains is fundamental to any bioarchaeological or forensic anthropological study. Biological and cultural interpretations of the remains depend on the age-estimation results. The acetabulum became a focus of age-estimation research at the beginning of this century, with early authors noting that this robust, relatively damage-resistant joint exhibited progressive changes that could be useful to estimate age at death in adults (Rissech and Malgosa, 2000; Rissech, 2001; Rissech et al., 2001; Rougé-Maillart, 2000; Rougé-Maillart et al., 2004).
In 2006, Rissech and collaborators proposed seven variables of the acetabulum (1, acetabular groove; 2, rim shape; 3, rim porosity; 4, apex activity; 5, activity on the outer edge of the rim fossa; 6, activity of the acetabular fossa; 7, porosities of the acetabular fossa) useful for estimating age in adult males (n=242, Coimbra, Portugal). Each of the seven variables of the acetabulum was broken into different states describing the different morphological conditions of the acetabular region (e.g., acetabular groove can be scored as: no groove [0], groove [1], pronounced groove [2], and very pronounced groove [3]). The method was validated on 394 male individuals from four documented Western European collections: the Coimbra and Lisbon collections from Portugal, the Universitat Autonònoma de Barcelona collection from Spain, and the St. Bride collection from England (Rissech et al., 2007). Their results indicated significant correlation between all the acetabular variables and age, illustrating the potential value of the acetabulum as an age marker for young, middle-aged, and older adults.
These studies utilized a freely distributed MS2 computer program named IDADE2 (“idade” is the Portuguese word for “age”). The IDADE2 program was developed by the late Professor George Estabrook of the University of Michigan to facilitate calculations for age prediction by Bayesian inference (Rissech et al., 2006). Now, to renew IDADE2 with an easier performance and broader applicability, we have re-written IDADE2 in the open source software R. This new IDADE2 web page is a free web server that allows users to work with: (1) our acetabular reference collections as a reference for acetabular age estimation of your test samples (IDADE2-Option 1); and (2) your own reference collections as a reference for age estimation of your test sample (IDADE2-Option 2).
Population differences
The applicability of the Rissech et al. (2006) method has been demonstrated on various European and European-American samples (Powanda, 2008; Miranker, 2016; San-Millán et al., 2017a). However, there is population variability in the age-related morphological changes of the acetabulum. Specifically, Iberian individuals seem to present a similar aging pattern (tendency toward bone production on the acetabular rim and fossa), whereas most English individuals do not exhibit this bone-formation tendency (Rissech et al., 2007). This Iberian pattern has also been observed in modern Colombian acetabula—possibly due to the recent historical and biological relationship between these two regions—but not in modern Scottish individuals (data not published; summarized in Rissech, 2013). As Mays (2015) has pointed out, age-related changes in most adult skeletal age indicators predominantly involve bone formation. This is also the case in the acetabulum, where most age-related changes involve bone production around the border of the lunate surface (San-Millán et al., 2017a), and bone loss seems to have little influence on the seven variables of the Rissech et al. (2006) method (Rissech et al., 2004; 2018). However, the degree of bone formation with aging seems, in general terms, to be variable between populations, depending on where the population lies on the bone-former/bone-loser continuum (Schmitt et al., 2007; Rissech, 2013; Mays, 2015). The new IDADE2 web page (Option 1) offers the choice of multiple European, Euro-American and South American reference samples, so that users can select the sample that is biologically and/or geographically closest to the remains under study. For users studying remains that are more distantly related to the samples currently available in IDADE2, Option 2 may be selected, and the user’s own reference data uploaded (also see “The future of acetabular age estimation,” below).
Sex differences
Differences in bone production have also been described between males and females, with males having a tendency to form more bone and females a tendency to lose it (see Schneider et al., 2002). Yet, multiple authors report no sex differences in acetabular age estimates (Calce, 2012; Rougé-Maillart et al., 2007; Stull and James, 2010), and recent research indicates a common aging pattern in acetabular shape—particularly in the regions that experience osteophytic proliferation (San-Millán, 2015; San-Millán et al., 2017b). The pace of acetabular change differs, however, between males and females (Mays, 2012; San-Millán 2015; San-Millán et al., 2017b), with females generally aging at a slower rate, possibly linked with their smaller body size (Campanacho, 2016). The similar aging pattern in both sexes suggests that the same acetabular variables can be applied in males and females; however, because of sex-based differences in aging pace, it is advisable to use sex-specific reference samples. The new IDADE2 web page (Option 1) gives the user the option of choosing male, female, or combined-sex reference samples when generating age estimates from acetabular data.
New acetabular variable definitions
Some research has suggested a low correlation with age for variables related to the acetabular fossa (Calce and Rogers, 2011; Calce, 2012; Mays, 2012). Specifically, previous authors have taken issue with variables V5, V6, and V7 of the Rissech et al. (2006) method, indicating their difficulty to score. For this reason, San-Millán and collaborators (2017b) revised and better defined the acetabular fossa variables of the original method (V5, V6, and V7) and extended the applicability of this new approach to both sexes. The result of this study is the revised “SanMillán-Rissech” method. In this method, variables V1-V4 are the same as in the original method (Rissech et al. 2006), with some small clarifications, and variables V5, V6 and V7 are modified (San-Millán et al. 2017b).
In the IDADE2 web page (Option 1), we provide the user with the opportunity to work with: (i) reference samples based on the Rissech et al. (2006) method (titled “Valladolid”,
“Bass”
and “Colombia”;
and (ii) reference samples based on the revised SanMillán-Rissech (2017b) method (titled “Lisbon” and “Bass”). These IDADE2-Option 1 datasets were collected from known-age collections of skeletal individuals in Spain, Portugal, the United States and Colombia. Those collections are: the Universidad de Valladolid skeletal collection (20th-century Spanish); the Collection of Identified Human Skeletons curated at the National Museum of Natural History, Universidade de Lisboa (19th-20th-century Portuguese); the William M. Bass Donated Skeletal Collection, curated at the Forensic Anthropology Center of the University of Tennessee (20th-21st-century American) and the Colombian Human Bone Reference Collection (COHRC) curated at the National Institute of Legal Medicine and Forensic Sciences of Colombia (20th-century). Allysha P. Winburn (Powanda, 2008) collected the Valladolid (Spain) data, Marta San-Millán collected the Bass data (San-Millán et al., 2019) and Vanessa Muñoz-Silva collected the Colombian
data (Muñoz-Silva et al., 2020), all of them using the Rissech et al. (2006) method. Marta San-Millán collected and updated the Lisbon and Bass data using the SanMillán-Rissech method
(San-Millán et al., 2017b; 2019).
The future of acetabular age estimation
In modern European-American individuals, acetabular age changes are strongly positively correlated with age and relatively resistant to the influences of physical activity and obesity—the latter of particular concern when estimating age in modern individuals (Winburn, 2017). With the creation of the IDADE2 website, we are pleased to offer the IDADE2 user the options of several acetabular reference datasets originating from European, Euro-American and South American populations. We look forward to updating these options when further testing evaluates the applicability of these methods (Rissech et al., 2006, San-Millán et al., 2017b) to skeletal samples from other ancestral populations.
References
Calce ES. 2012. A new method to estimate adult age-at-death using the acetabulum. American Journal of Physical Anthropology, 148:11–23.
Calce ES, Rogers TL. 2011. Evaluation of age estimation technique: testing traits of the acetabulum to estimate age at death in adult males. Journal of Forensic Science, 56:302–311.
Campanacho V. 2016. Influence of skeletal size on age-related criteria from the pelvic joints in Portuguese and American samples. PhD Thesis, University of Sheffield, Department of Archaeology
Mays S. 2012. An investigation of age-related changes at the acetabulum in 18th–19th century AD adult skeletons from Christ Church Spitalfields, London. American Journal of Physical Anthropology, 149:485–492.
Mays S. 2015. The effect of factors other than age upon skeletal age indicators in the adult. Annals of Human Biology, 42:332–341.
Miranker M. 2016. A Comparison of Different Age Estimation Methods of the Adult Pelvis. Journal of Forensic sciences, 61:1173-1179.
Muñoz-Silva V, Sanabria-Medina C, Rissech C. 2020. Application and analysis of the Rissech acetabular adult aging method in a Colombian sample. International Journal of Legal Medicine, DOI 10.1007/s00414-020-02422-w.
Powanda A. 2008. A comparison of pelvic age-estimation methods on two modern Iberian populations: bioarchaeological and forensic implications. Master’s dissertation, New York University.
Rissech C. 2001. Anàlisi del creixement del coxal a partir de material ossi i les seves aplicacions en la Medicina Forense i l’Antropologia, Ph.D. dissertation, Universitat Autònoma de Barcelona, Barcelona.
Rissech C. 2013. letter to the Editor: Comments on “A new method to estimate adult age-at-death using the acetabulum” (Calce, 2012). American Journal of Physical Anthropolgy, 151: 331-332, 2013.
Rissech C, Joana Appleby, Alessandra Cosso, Francisco Reina, Anna Carrera, Richard Thomas. 2018. The influence of bone loss on the three adult age markers of the innominate. International Journal of Legal Medicine, 132: 289-300.
Rissech C, Estabrook F. G, Cunha E, Malgosa A. 2006. Using the acetabulum to estimate age at death of adult males. Journal of Forensic Science, 51: 213-229.
Rissech C, Estabrook F. G, Cunha E, Malgosa A. 2007. Estimation of Age-at-Death for Adult Males Using the Acetabulum, Applied to Four Western European Populations. Journal of Forensic Science, 52:774-779.
Rissech C, Malgosa A. 2000. Longitud del isquion desde el nacimiento hasta la vejez: diagnóstico de edad y sexo. In: Varela T, editor. Investigaciones en Biodiversidad Humana. Santiago de Compostela (Spain): Universidad de Santiago de Compostela, p. 350–357.
Rissech C, Sañuudo JR, Malgosa A. 2001. Acetabular point: a morphological and ontogenetic study. Journal of Anatomy, 198:743–8.
Rissech C, Schmitt A, Malgosa A, Cunha E. 2004. Influencia de las patologías en los indicadores de edad adulta del coxal: estudio preliminar. Antropologia Portuguesa, 20/21: 265-277.
Rougé-Maillart C. 2000. Estimation de l’âge à partir de la partie postérieure du bassin: étude comparée de la surface auriculaire et du cotyle, diplôme d’étude approfondie d’, Anthropologie dissertation, Université de Toulouse le Mirail, Toulouse.
Rougé-Maillart CL, Telmon N, Rissech C, Malgosa A, Rougé D. 2004. The determination of male adult age by central and posterior coxal analysis. A preliminary study. Journal of Forensic Sciences,49:1–7.
Rougé-Maillart C, Jousset N, Vielle B, Gaudin A, Telmon N. 2007. Contribution of the study of acetabulum for the estimation of adult subjects. Forensic Sci Int 171:103–110 28.
San-Millán M. 2015. Estudio de la variabilidad morfológica del acetábulo y los caracteres de senescencia de la región acetabular y otros marcadores de edad del hueso coxal mediante series osteológicas. Aplicaciones en antropología y medicina forense. PhD dissertation, Universitat de Barcelon.
San-Millán M., Rissech C, Turbón D. 2017a. Shape variability of the adult human acetabulum and acetabular fossa related to sex and age by geometric morphometrics. Implications for adult age estimation. Forensic Science International, 272:50-63.
San-Millán M., Rissech C, Turbón D. 2017b. New approach to age estimation of male and female adult skeletons based on the morphological characteristics of the acetabulum. International Journal of Legal Medicine, 131:501-525.
San-Millán M, Rissech C, Turbón D. 2019. Application of the recent SanMillán-Rissech acetabular adult aging method in a North American sample. International Journal of Legal Medicine, 133: 909-920.
Schmitt A,Wapler V, Couallier V, Cunha E. 2007. Are bone losers distinguishable from bone formers in a skeletal series? Implications for adult age at death assessment methods. Homo, 58:53–66.
Schneider DL, Barrett-Connor E, Morton DJ, Weisman M. 2002. Bone mineral density and clinical hand osteoarthritis in elderly men and women: the Rancho Study. Journal of Rheumatology, 29:1467–1472.
Stull KE, James DM. 2010. Determination of age at death using the acetabulum of the os coxa. In: Latham KE, Finnegan M (eds) Age estimation of the human skeleton. Charles C. Thomas, Springfield, pp 134–146.
Winburn AP. 2017. Skeletal age estimation in modern European-American adults: The effects of activity, obesity, and osteoarthritis on age-related changes in the acetabulum. PhD Dissertation, University of Florida, Department of Anthropology.
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