1
|
Stull KE, Chu EY, Corron LK, Price MH. Mixed cumulative probit: a multivariate generalization of transition analysis that accommodates variation in the shape, spread and structure of data. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220963. [PMID: 36866077 PMCID: PMC9974299 DOI: 10.1098/rsos.220963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Biological data are frequently nonlinear, heteroscedastic and conditionally dependent, and often researchers deal with missing data. To account for characteristics common in biological data in one algorithm, we developed the mixed cumulative probit (MCP), a novel latent trait model that is a formal generalization of the cumulative probit model usually used in transition analysis. Specifically, the MCP accommodates heteroscedasticity, mixtures of ordinal and continuous variables, missing values, conditional dependence and alternative specifications of the mean response and noise response. Cross-validation selects the best model parameters (mean response and the noise response for simple models, as well as conditional dependence for multivariate models), and the Kullback-Leibler divergence evaluates information gain during posterior inference to quantify mis-specified models (conditionally dependent versus conditionally independent). Two continuous and four ordinal skeletal and dental variables collected from 1296 individuals (aged birth to 22 years) from the Subadult Virtual Anthropology Database are used to introduce and demonstrate the algorithm. In addition to describing the features of the MCP, we provide material to help fit novel datasets using the MCP. The flexible, general formulation with model selection provides a process to robustly identify the modelling assumptions that are best suited for the data at hand.
Collapse
Affiliation(s)
- Kyra E. Stull
- Department of Anthropology, University of Nevada, 1664 North Virginia Street, Stop 0096, Reno, NV 89557, USA
- Forensic Anthropology Research Centre, Department of Anatomy, University of Pretoria, Private Bag x323, 0007 Pretoria, South Africa
| | - Elaine Y. Chu
- Department of Anthropology, University of Nevada, 1664 North Virginia Street, Stop 0096, Reno, NV 89557, USA
| | - Louise K. Corron
- Department of Anthropology, University of Nevada, 1664 North Virginia Street, Stop 0096, Reno, NV 89557, USA
| | | |
Collapse
|
2
|
Niel M, Adalian P. New models to estimate fetal and young infant age with the pars basilaris biometry. Forensic Sci Int 2023; 342:111531. [PMID: 36455452 DOI: 10.1016/j.forsciint.2022.111531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 11/13/2022] [Accepted: 11/22/2022] [Indexed: 11/27/2022]
Abstract
The pars basilaris of the occipital bone is often found intact when fetal or infant bones are discovered. In the literature, several methods use measurements of this bone for juvenile's age-at-death estimation, but it has already been demonstrated that they can come along methodological and statistical biases. In this study, new age prediction formulas were created from a learning sample of 208 CT scans of fetuses and infants from Marseilles (France) with normal development. The two statistically validated models, with a prediction interval of 95 % of reliability, were tested on a separate sample of 68 individuals, for which we ensured that they did not show any developmental pathology. Models show an average of 97.06 % of correct age estimates, compared to less than 26.6 % when using previously published which tend to overestimate age. The new age estimation formulas make it possible to estimate fetuses and infants age with very good results up to 2 postnatal months. Results are both reliable and precise enough for forensic practice, and we provide an automated tool (a simple excel spreadsheet) to ensure an easy and quick access to the application of this method.
Collapse
Affiliation(s)
- Mélissa Niel
- Aix Marseille Univ, CNRS, EFS, ADES, Marseille, France.
| | | |
Collapse
|
3
|
Age estimation in infant skeletal remains by measurements of the pars lateralis. Int J Legal Med 2022; 136:1675-1684. [PMID: 35857123 DOI: 10.1007/s00414-022-02867-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/11/2022] [Indexed: 10/17/2022]
Abstract
The objectives of this work were to validate two published methods for subadult age estimation based on measurements of the pars lateralis, and to develop a new method based on a wider set of measurements using the Granada Osteological Collection. The pars lateralis of 127 individuals from 6 months prenatal to 4 years of age were measured, taking 6 measurements of the body, the anterior synchondrosis and the condyle. Length and width were used to validate the published methods. Regression functions using age as the independent variable were calculated using each of the six measurements taken, and functions for age estimation were obtained through classical calibration. Functions for calculation of the 95% confidence interval of the estimates were obtained through linear regression using the estimation errors. In the validation of the previous methods, one method showed a linear tendency of the differences, which can be attributed to a circularity in reasoning in the original work. In the other method, a tendency towards overestimation was found, which can be attributed to the limitations of the method itself. The new functions have a consistency rate of 92.2% to 97.1%; the functions derived from all measurements are useful from 6 months prenatal to 2 years of age. Moreover, the functions obtained are applicable to incomplete pars lateralis, allowing for age estimation in a wide set of contexts and providing straightforward age estimates with their respective margin of error.
Collapse
|
4
|
Smith DEM, Humphrey LT, Cardoso HFV. Age estimation of immature human skeletal remains from mandibular and cranial bone dimensions in the postnatal period. Forensic Sci Int 2021; 327:110943. [PMID: 34455396 DOI: 10.1016/j.forsciint.2021.110943] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/21/2021] [Accepted: 08/09/2021] [Indexed: 10/20/2022]
Abstract
Age estimation is one of the crucial first steps in the identification of human skeletal remains in both forensic and archeological contexts. In the postnatal period, age is traditionally estimated from dental development or skeletal growth, typically long bone diaphyseal length. However, in many occasions other methods are required. This study provides alternative means of estimating age of juvenile remains from the size of several cranial bones and the mandible. A sample of 185 identified juvenile skeletons between birth and 13 years of age from two European collections were used (Lisbon and Spitalfields). Measurements of the frontal, occipital-lateralis, occipital-basilaris, occipital-squamous, zygomatic, maxilla, and mandible were used to calculate classical calibration regression formulae for the sexes combined. The sample was divided into three age groups birth-2 years, 2-6 years, and 2-12.9 years, depending on bone and its growth trajectory. For all the bones, measurements of the youngest age groups yielded the most precise age estimates. The vault bones on average yielded the best performing models, with the frontal bone having the most precise of all. The mandible performed on par with the best performing cranial bones, particularly in individuals under the age of 2 years. This study provides one of the most comprehensive approaches to juvenile age estimation based on bones of the skull, providing a resource that potentially can help estimate age of juvenile skeletons from a variety of circumstances.
Collapse
Affiliation(s)
- Deanna E M Smith
- Department of Archaeology, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - Louise T Humphrey
- Centre for Human Evolution Research, Department of Earth Sciences, The Natural History Museum, London SW7 5BD, United Kingdom
| | - Hugo F V Cardoso
- Department of Archaeology, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada.
| |
Collapse
|
5
|
Lamer M, Spake L, Cardoso HFV. Testing the cross-applicability of juvenile sex estimation from diaphyseal dimensions. Forensic Sci Int 2021; 321:110739. [PMID: 33662898 DOI: 10.1016/j.forsciint.2021.110739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/10/2021] [Accepted: 02/17/2021] [Indexed: 10/22/2022]
Abstract
Sex estimation is a crucial component of the biological profile. Stull et al. (2017) have proposed a promising juvenile sex estimation method using long bone measurements taken from a South African sample, providing relatively high classification accuracies and made easy to use via the KidStats web-based app. In this study, we test the models developed by Stull et al. (2017) on an external historic population from Lisbon, Portugal, in order to determine whether the models can be reliably applied to archeological and forensic populations outside of the original population sample. The study sample consisted of 102 individuals (45 females and 57 males) aged under 13 years at death from the Lisbon identified skeletal collection. Measurements from these individuals were used to test the flexible discriminant analysis (FDA) models given by Stull et al. (2017). Allocation accuracies were calculated for boys and girls and children over and under 2 years separately and combined. Our findings show that the models developed by Stull et al. (2017) yield poor accuracy when applied to our external population and thus can potentially be misapplied on archeological skeletal remains or forensic remains of unknown origin. A number of statistical issues may explain why models fail to be transportable or even generalizable, namely multicollinearity, model overfitting and overly optimist bootstrapped cross-validation rates. It is also likely that population differences in size and sexual size dimorphism also affected the applicability of the models. We emphasize the importance of externally validating prediction models, particularly if they are intended to be applied across populations. Our study addresses Stull and co-worker's request for further validation of the method on populations outside of South Africa, as the models cannot be confidently applied in the field until it has been externally validated.
Collapse
Affiliation(s)
- Madeleine Lamer
- Department of Anthropology, McMaster University, Hamilton, Ontario, Canada
| | - Laure Spake
- Religion Programme and Centre for Research on Evolution, Belief, and Behaviour, University of Otago, Dunedin, New Zealand
| | - Hugo F V Cardoso
- Department of Archaeology, Simon Fraser University, Burnaby, British Columbia, Canada.
| |
Collapse
|
6
|
Stull KE, Wolfe CA, Corron LK, Heim K, Hulse CN, Pilloud MA. A comparison of subadult skeletal and dental development based on living and deceased samples. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 175:36-58. [PMID: 33245147 DOI: 10.1002/ajpa.24170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/21/2020] [Accepted: 10/29/2020] [Indexed: 12/17/2022]
Abstract
OBJECTIVES A fundamental assumption in biological anthropology is that living individuals will present with different growth than non-survivors of the same population. The aim is to address the question of whether growth and development data of non-survivors are reflective of the biological consequences of selective mortality and/or stress. MATERIALS AND METHODS The study compares dental development and skeletal growth collected from radiographic images of contemporary samples of living and deceased individuals from the United States (birth to 20 years) and South Africa (birth to 12 years). Further evaluation of deceased individuals is used to explore differential patterns among manners of death (MOD). RESULTS Results do not show any significant differences in skeletal growth or dental development between living and deceased individuals. However, in the South African deceased sample the youngest individuals exhibited substantially smaller diaphyseal lengths than the living sample, but by 2 years of age the differences were negligible. In the US sample, neither significant nor substantial differences were found in dental development or diaphyseal length according to MOD and age (>2 years of age), though some long bones in individuals <2 years of age did show significant differences. No significant differences were noted in diaphyseal length according to MOD and age in the SA sample. DISCUSSION The current findings refute the idea that contemporary deceased and living individuals would present with differential growth and development patterns through all of ontogeny as well as the assumptions linking short stature, poor environments, and MOD.
Collapse
Affiliation(s)
- Kyra E Stull
- Department of Anthropology, University of Nevada, Reno, Nevada, USA.,Department of Anatomy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | | | - Louise K Corron
- Department of Anthropology, University of Nevada, Reno, Nevada, USA
| | | | - Cortney N Hulse
- Department of Anthropology, University of Nevada, Reno, Nevada, USA
| | - Marin A Pilloud
- Department of Anthropology, University of Nevada, Reno, Nevada, USA
| |
Collapse
|
7
|
Age estimation in forensic anthropology: methodological considerations about the validation studies of prediction models. Int J Legal Med 2019; 133:1915-1924. [PMID: 31073637 DOI: 10.1007/s00414-019-02064-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/05/2019] [Indexed: 10/26/2022]
Abstract
There is currently no clear consensus on how to calculate, express, and interpret the error when validating methods for age estimation in forensic anthropology. For this reason, it is likely that researchers are commonly drawing erroneous or confusing conclusions about the existence of population differences or the need to design new and increasingly complex estimation methods. In recent years, many researchers have highlighted these limitations. They propose new lines of research focused on the use of rigorous statistics and new technologies for the development of methods for estimating age. Our main objective in this study is to contribute to the strengthening of these novel ideas, for which we show the existing empirical evidence about the inadequacy of some age estimation methods in calculating, expressing, and interpreting the errors obtained. With this aim, a total of 500 simulations have been performed, in which hypothetical research teams develop and validate methods for age estimation. The data employed in this study was obtained from the "Centers for Disease Control and Prevention (CDC) Growth Charts: United States" released in 2000. The charts relate age with height, weight, and head circumference of US male children. Five learning algorithms have been employed as age estimators. We have performed three experiments in which the following aspects have been analyzed: frequency with which "negative" results can be obtained in the validation studies; which are the most appropriate criteria to compare and select the age estimation methods; and what analysis should be employed to carry out the validation studies. The results show possible errors in the interpretation of validation studies as a consequence of the confusion of statistical concepts. To conclude, we made a proposal of "good practices" for the correct calculation, expression, and interpretation of the error when validating age estimation methods in forensic anthropology.
Collapse
|
8
|
Cardoso HFV, Meyers J, Liversidge HM. A Reappraisal of Developing Deciduous Tooth Length as an Estimate of Age in Human Immature Skeletal Remains. J Forensic Sci 2018; 64:385-392. [PMID: 30129157 DOI: 10.1111/1556-4029.13892] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/19/2018] [Accepted: 08/01/2018] [Indexed: 11/26/2022]
Abstract
This study provides an update on a quantitative method for immature age estimation based on postnatal deciduous mandibular tooth length. Two known sex and age skeletal collections from Western Europe were sampled (n = 97). Linear regression models for age estimated were calculated for each individual tooth, each sex, and sex combined sample using classical calibration. Prediction errors, residuals, and percentage of individuals whose real age fell within the 95% prediction interval were calculated. The teeth which develop earlier in life, the incisors and the first molar, showed the greatest precision, while the canine showed the least. This method has greater applicability to archeological skeletons or to children in developing countries than for use in North American or European forensic contexts. The method can be applied to incomplete or poorly preserved remains of unknown sex, particularly when dental radiographs are not an option or when teeth have been removed from the alveolus or crypt.
Collapse
Affiliation(s)
- Hugo F V Cardoso
- Department of Archaeology and Centre for Forensic Research, Simon Fraser University, Burnaby, BC, Canada, V5A 4X7
| | - Julia Meyers
- Department of Archaeology and Centre for Forensic Research, Simon Fraser University, Burnaby, BC, Canada, V5A 4X7
| | - Helen M Liversidge
- Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Institute of Dentistry, Turner Street, London, E1 2AD, U.K
| |
Collapse
|
9
|
A critical review of sub-adult age estimation in biological anthropology: Do methods comply with published recommendations? Forensic Sci Int 2018; 288:328.e1-328.e9. [DOI: 10.1016/j.forsciint.2018.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/16/2018] [Accepted: 05/08/2018] [Indexed: 11/18/2022]
|
10
|
Viciano J, De Luca S, Irurita J, Alemán I. Age Estimation of Infants Through Metric Analysis of Developing Anterior Deciduous Teeth. J Forensic Sci 2017; 63:20-30. [PMID: 28382630 DOI: 10.1111/1556-4029.13505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/08/2017] [Accepted: 03/02/2017] [Indexed: 11/27/2022]
Abstract
This study provides regression equations for estimation of age of infants from the dimensions of their developing deciduous teeth. The sample comprises 97 individuals of known sex and age (62 boys, 35 girls), aged between 2 days and 1,081 days. The age-estimation equations were obtained for the sexes combined, as well as for each sex separately, thus including "sex" as an independent variable. The values of the correlations and determination coefficients obtained for each regression equation indicate good fits for most of the equations obtained. The "sex" factor was statistically significant when included as an independent variable in seven of the regression equations. However, the "sex" factor provided an advantage for age estimation in only three of the equations, compared to those that did not include "sex" as a factor. These data suggest that the ages of infants can be accurately estimated from measurements of their developing deciduous teeth.
Collapse
Affiliation(s)
- Joan Viciano
- Operative Unit of Anthropology, Department of Medicine and Ageing Sciences, 'G. d'Annunzio' University of Chieti-Pescara, Piazza Trento e Trieste 1, Chieti, 66100, Italy
| | - Stefano De Luca
- Unidad Especial de Identificación Forense, Servicio Médico Legal, Avenida La Paz 1012, Comuna de Independencia, Santiago de Chile, Chile
| | - Javier Irurita
- Laboratory of Anthropology, Department of Legal Medicine, Toxicology and Physical Anthropology, University of Granada, Avenida de la Investigación 11, Granada, 18071, Spain
| | - Inmaculada Alemán
- Laboratory of Anthropology, Department of Legal Medicine, Toxicology and Physical Anthropology, University of Granada, Avenida de la Investigación 11, Granada, 18071, Spain
| |
Collapse
|