Multifactorial determination of skeletal age at death: A method and blind tests of its accuracy

Abstract

Traditional methods of estimating skeletal age at death have relied solely on the pubic symphyseal face or on this indicator combined with others in nonsystematic ways. A multifactorial method is presented that uses a principal components weighting of five indicators (public symphyseal face, auricular surface, radiographs of proximal femur, dental wear, and suture closure). This method has been tested by completely blind assessment of age in two samples from the Todd collection carefully screened for accuracy of stated age at death. Results show a marked superiority of the multifactorial method over any single indicator with respect to both bias and accuracy. This represents the first truly blind test of an age-at-death indicator or system, as the test populations were independent of the system(s) being tested, and the age, sex, and ethnogeographic origin of the individuals being assessed (as well as the compositions of the test samples with respect to these variables) were completely unknown until the tests were completed. Implications for paleodemography are discussed.

Estimating age and the likelihood of having attained 18 years of age using mandibular third molars

“…37 Measures such as bias, SD of bias, mean absolute difference between dental and known ages, diagnostic tests, and Bayesian statistics are all useful to determine which method is best. 34,37 It is clear from our results that only a handful of methods estimated age with little bias and the two detailed in Table 2 are the recommended methods of choice. Few previous studies compare performance of M3 age estimation.…”

“…33 Actual age was subtracted from dental age and mean difference (defi ned as bias), standard deviation (SD) and mean absolute difference were calculated for each method. 34 Bias was tested using the t-test with significance level of 0.05. Methods with bias not signifi cant to zero were further analysed by root stage.…”

“…Absolute mean difference is another measure of accuracy. 34 In order to test bias and accuracy, several important features of both target and reference sample should be fulfi lled such as suffi cient number, a suffi ciently wide age range in order to include early and late maturing individuals and a uniform age distribution. 36 Having similar numbers across the age range ensures that accuracy is consistent over the entire age immature target sample.…”

Temuan Rangka Homo sapiens di Situs Gua Kidang

“…Identifikasi dilakukan untuk memperoleh data demografis, yaitu afiliasi populasi berdasarkan studi dari Lahr (Lahr, 1996), jenis kelamin (sistem skoring dari Acsadi & Nemeskeri (Acsadi & Nemeskeri, 1970), umur berdasarkan sistem penentuan umur dari Brothwell (Brothwell, 1965); (Lovejoy, C.O, Meindl, R.S, Mensforth R.P, and Barton, 1985), dan tinggi badan individu berdasarkan formula dari Pearson dan Sjovold (Lovejoy, C.O, Meindl, R.S, Mensforth R.P, and Barton, 1985). Pemeriksaan kondisi patologis pada sisa rangka juga dilakukan dengan menggunakan deskripsi dari Ortner (Ortner, J, & Walter G.J.…”

“…Sutura cranium yang masih teramati adalah bagian obelion, sagittalis anterior, bregma, dan coronalis medial, semuanya terdapat pada kubah tengkorak. Pertautan sutura pada keempat titik tersebut ada pada tingkat signifikan dengan skor 2 (Lovejoy, C.O, Meindl, R.S, Mensforth R.P, and Barton, 1985). Metode Meindl & Lovejoy dipakai didasarkan sampai saat ini alasan hal tersebut menjadi satu-satunya yang dapat digunakan untuk estimasi umur melalui gigi dan sutura cranium.…”