Conference Presentations by Megan E . Ingvoldstad, PhD, D-ABFA
AAFS Annual Conference, 2023
▪Overall, subadult age had little bearing on experienced analysts' abilities to identify correct ... more ▪Overall, subadult age had little bearing on experienced analysts' abilities to identify correct pair matches ▪Diaphysis length, epiphyseal fusion, torsion, and muscle insertion sites were more confidently pair matched in most subadult groups compared to the adult humeri test, due to fewer subadult asymmetrical differences This research impacts anthropologists conducting identification projects with CHR. As commingled individuals with unfused and fusing epiphyses are encountered in various contexts 1, 4, 5, 6 this research indicates that experienced analysts can pair match subadult remains >1 year of age with 100% accuracy. Diminished morphological variability among long bones of 0-1 year suggests analysts should increase caution when assigning pair matches to individuals <1 year old
AAFS Annual Meeting, 2019
Antimeric leg length asymmetry is often encountered in forensic anthropological casework. Guidanc... more Antimeric leg length asymmetry is often encountered in forensic anthropological casework. Guidance is provided regarding how to estimate stature when asymmetry is present to avoid inaccurate stature estimates and erroneous exclusion of a decedent as a match to their skeletal remains.
After attending this presentation, attendees will understand the current issues with histological... more After attending this presentation, attendees will understand the current issues with histological age estimation, and the effect that region of interest (ROI) size has on the relationship between osteon population density (OPD) and age-at-death estimation.
This presentation will impact the forensic science community by demonstrating that the amount of bone sampled/analyzed in histological age assessment can have a profound impact on the ability to accurately estimate age-at-death. This will inform future histological research, resulting in higher quality forensic research and practice.
As a complement to macroscopic aging methods, or when necessary macroscopic elements are damaged/absent, age can be estimated through histological examination of remodeling events in cortical bone. To date, the femoral midshaft has been the most commonly employed site for histological studies; however, a consensus is lacking on how much bone to analyze when quantifying remodeling, as existing methods employ ROIs that differ in size, number, and location.
Recently, histological research at the femoral midshaft has proliferated due to the revival of the Ericksen femur collection as an active resource. The current study is a meta-analysis of three recent studies that provide a unique opportunity to assess the effect of ROI size on the relationship between OPD and age. All three studies analyzed here (Ingvoldstad1, Crowder/Dominguez2, and Gocha3 methods) primarily utilized the Ericksen collection, examined the anterior region of the femur, and quantified remodeling according to the same standard histological definitions.
The Ingvoldstad method examined 200 individuals (97 males, 103 females), aged 30–97 years (average=71 years), all from the Ericksen collection; a fixed ROI size of 3.00 mm2 was used to quantify remodeling at eight anatomical and biomechanical locations around the femoral cortex, though only anterior data are analyzed here. The Crowder/Dominguez method examined 320 individuals (170 males, 150 females), aged 15–97 (average=66 years), 87% of which were from the Ericksen collection. This method used a topographic sampling strategy, separating a 5 mm wide section of the anterior femur into 10 columns and reading every other frame using a Merz reticule; this resulted in an average ROI size of 18.30 mm2, with an average of 9.52 mm2 of bone analyzed. The Gocha method examined only 30 individuals (15 male, 15 female), aged 21–97 years (average=59 years), 83% of which were from the Ericksen collection. This method examined remodeling over the entirety of the femoral midshaft, though only anterior octant and quadrant data are analyzed here; average octant ROI size was 41.82 mm2, average quadrant ROI size was 89.93 mm2.
Statistical analyses were performed in SPSS 23. Kolmogorov-Smirnov tests demonstrated OPD values for all methods to be normally distributed (all p-values >0.070). The relationship between OPD and age was assessed through Pearson’s correlation coefficients, as well as the adjusted R2 value of linear regression predictive models; all of these statistical measures were statistically significant (all p-values <0.043). One author (VMD), who collected the majority of the data for the Crowder/Dominguez method, also performed interobserver error measures for the Ingvoldstad and Gocha studies, neither of which demonstrated significant differences between observers.
The correlation coefficient for the Ingvoldstad method was R=0.143, and the adjusted R2=0.016, indicating OPD explained only 1.6% of the variation in age-at-death. The correlation coefficient for the Crowder/Dominguez method was R=0.681, and the adjusted R2=0.462, indicating OPD explained 46.2% of the variation in age-at-death. The correlation coefficient for the Gocha Octant method was R=0.907, and the adjusted R2=0.817, indicating OPD explained 81.7% of the variation in in age at death. For the Gocha Quadrant method, the correlation coefficient was R=0.918 and the adjusted R2=0.838, indicating OPD explained 83.8% of the variation in age at death.
Results indicate that ROI size has a significant effect on the ability to predict age-at-death from histological remodeling. Examination of small, isolated ROIs is not recommended, as such an approach is more susceptible to random variation in variable distribution and can negatively affect interpretation. Instead, future studies should examine larger ROIs to maximize histological remodeling’s ability to predict age-at-death.
"Same Same, but Different": Considerations and Approaches to Archaeology within the Defense POW/MIA Accounting Agency., 2017
The Defense POW/MIA Accounting Agency (DPAA) is the governmental entity tasked with the investiga... more The Defense POW/MIA Accounting Agency (DPAA) is the governmental entity tasked with the investigation, recovery, identification, and accounting for U.S. military members that have gone missing during conflict, while in service. This effort follows stringent scientific archaeologically-based protocols and practices, proving some degree of success especially for the resolution of incidents involving single-event site types such as aircraft crashes or burials. The archaeologist faces a challenging, dynamic environment when attempting to assess sites believed to be associated with loss incidents involving large-scale conflict that cover space as well as time. This paper will present current efforts for the targeted investigation and recovery of the missing from major fields of battle during World War II. The approach for this investigation involves the application of landscape archaeological principles, geospatial technologies, and the importance of the contextual relationship of material evidence with biological evidence.
Left/right total leg length asymmetries from 0.5 to 16 mm were observed in 68/78 [87.2%] cases (e... more Left/right total leg length asymmetries from 0.5 to 16 mm were observed in 68/78 [87.2%] cases (e.g., ). A significant difference was observed between left and right total leg lengths (4.96 mm average; between 4.05-5.86 mm; p < 0.00; t = 10.96; α = 0.05). Thus, Hypothesis #1 is accepted.
Materials and Methods 200 femoral midshafts of known orientation were harvested from George Washi... more Materials and Methods 200 femoral midshafts of known orientation were harvested from George Washington University Medical School Dissecting Room cadavers and processed for histological assessment .
Papers by Megan E . Ingvoldstad, PhD, D-ABFA
Journal of Forensic Sciences, 2024
This study reviews recent advances in osteometric, genetic, geochemical, and digital modeling app... more This study reviews recent advances in osteometric, genetic, geochemical, and digital modeling applications since 2014 to demonstrate the expanded range of analyses and skeletal elements that can be used to separate individuals from commingled contexts. While traditional methods remain foundational to commingling resolution, new advances allow increased individuation, identification of human versus non-human remains, and an amplified scale of assemblages that can be analyzed.
Journal of Forensic Sciences, 2022
Antimeric lower limb length asymmetry is frequently noted when measuring human skeletal remains. ... more Antimeric lower limb length asymmetry is frequently noted when measuring human skeletal remains. As lower limb bones are often used to estimate stature from unidentified remains, the forensic anthropologist who notes a disparity must then determine which lower limb bone or bones will produce an estimate that most accurately and precisely captures the unknown individual's stature. To help forensic anthropologists make informed decisions when remains exhibit lower limb antimeric asymmetry, left and right femora and fibulae maximum lengths were analyzed from 78 DPAAidentified individuals with measured statures. Results revealed 87.2% of individuals exhibited lower limb antimeric asymmetry, statistically significant differences between lower limb lengths, decreasing estimate accuracy when asymmetry increased, and that using a 99% prediction interval for disparities ≥5.0 mm nearly ensured documented measured stature would be captured. These findings were validated on independent samples of 20 adult males from the DPAA and 146 males and females from the Terry, Hamann-Todd, and Bass Collections. Preliminary results were largely supported; however, the accuracy reduction with increasing asymmetry observed in the DPAA data was not replicated. Based on these findings, we encourage bilateral measurement taking to identify lower limb antimeric asymmetry, caution against combining bone lengths from opposite sides, and recommend using a 99% prediction interval when lower limb length antimeric asymmetry is ≥5.0 mm and if using the FORDISC 3 Trotter M Stats database. When C Stats or F Stats are used, the prediction intervals associated with these less homogeneous databases are large enough to absorb error due to antimeric asymmetry.
The Fourth Cataract and Beyond: Proceedings of the 12th International Conference for Nubian Studies, 2014
Forensic Science International, 2015
Most macroscopic skeletal aging techniques used by forensic anthropologists have been developed a... more Most macroscopic skeletal aging techniques used by forensic anthropologists have been developed and tested only on reference material from western populations. This study examined the performance of six aging techniques on a known age sample of 88 Southeast Asian individuals. Methods examined included the Suchey-Brooks method of aging the symphyseal face of the os pubis (Brooks and Suchey 1990), Buckberry and Chamberlain’s (2002) and Osborne et al.’s (2004) revisions of the Lovejoy et al. (1985) method of aging the auricular surface of the ilium, İşcan et al.’s (1984, 1985) method of aging the sternal end of the fourth rib, and Meindl and Lovejoy’s (1985) methods for aging both lateral-anterior and vault sutures on the cranium. The results of this study indicate that application of aging techniques commonly used in forensic anthropology to individuals identified as Asian, and more specifically Southeast Asian, should not be undertaken injudiciously. Of the six individual methods tested here, the Suchey-Brooks pubic symphysis aging method performs best, though average age estimates were still off by nearly 10 years or greater. Methods for aging the auricular surface perform next best, though the Osborne et al. method works better for individuals below 50 years and the Buckberry and Chamberlain method works better for those above 50 years. Methods for age estimation from the sternal ends of the fourth rib and vault and lateral-anterior cranial sutures perform poorly and are not recommended for use on remains of Southeast Asian ancestry. Combining age estimates from multiple indicators, specifically the pubic symphysis and one auricular surface method, was superior to individual methods. Data and a worked example are provided for calculating the conditional probability that an individual belongs to a particular age decade, though overall age estimates may still be broad.
Contributing to a Sudanese archaeological salvage project in anticipation of the Merowe Dam, memb... more Contributing to a Sudanese archaeological salvage project in anticipation of the Merowe Dam, members of the Oriental Institute Nubian Expedition (OINE) excavated three cemetery sites during the winters of 2007–2008. Located within the Fourth Cataract region, Al-Widay I, Al-Widay II, and Umm Gebir Island cemeteries yielded the remains of 129 skeletons. Here, a preliminary summary of all recovered Al-Widay I remains is presented that addresses demography, morphology, and skeletal health of the
individuals analyzed.
Use of microscopic techniques to estimate adult age at death is well established within physical ... more Use of microscopic techniques to estimate adult age at death is well established within physical anthropology's subfields of bioarchaeology and forensic anthropology. In order to become a more robust approach, however, the long-standing problems of the osteon population density (OPD) asymptote and high standard error of the estimate (SEE) must be overcome.
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Conference Presentations by Megan E . Ingvoldstad, PhD, D-ABFA
This presentation will impact the forensic science community by demonstrating that the amount of bone sampled/analyzed in histological age assessment can have a profound impact on the ability to accurately estimate age-at-death. This will inform future histological research, resulting in higher quality forensic research and practice.
As a complement to macroscopic aging methods, or when necessary macroscopic elements are damaged/absent, age can be estimated through histological examination of remodeling events in cortical bone. To date, the femoral midshaft has been the most commonly employed site for histological studies; however, a consensus is lacking on how much bone to analyze when quantifying remodeling, as existing methods employ ROIs that differ in size, number, and location.
Recently, histological research at the femoral midshaft has proliferated due to the revival of the Ericksen femur collection as an active resource. The current study is a meta-analysis of three recent studies that provide a unique opportunity to assess the effect of ROI size on the relationship between OPD and age. All three studies analyzed here (Ingvoldstad1, Crowder/Dominguez2, and Gocha3 methods) primarily utilized the Ericksen collection, examined the anterior region of the femur, and quantified remodeling according to the same standard histological definitions.
The Ingvoldstad method examined 200 individuals (97 males, 103 females), aged 30–97 years (average=71 years), all from the Ericksen collection; a fixed ROI size of 3.00 mm2 was used to quantify remodeling at eight anatomical and biomechanical locations around the femoral cortex, though only anterior data are analyzed here. The Crowder/Dominguez method examined 320 individuals (170 males, 150 females), aged 15–97 (average=66 years), 87% of which were from the Ericksen collection. This method used a topographic sampling strategy, separating a 5 mm wide section of the anterior femur into 10 columns and reading every other frame using a Merz reticule; this resulted in an average ROI size of 18.30 mm2, with an average of 9.52 mm2 of bone analyzed. The Gocha method examined only 30 individuals (15 male, 15 female), aged 21–97 years (average=59 years), 83% of which were from the Ericksen collection. This method examined remodeling over the entirety of the femoral midshaft, though only anterior octant and quadrant data are analyzed here; average octant ROI size was 41.82 mm2, average quadrant ROI size was 89.93 mm2.
Statistical analyses were performed in SPSS 23. Kolmogorov-Smirnov tests demonstrated OPD values for all methods to be normally distributed (all p-values >0.070). The relationship between OPD and age was assessed through Pearson’s correlation coefficients, as well as the adjusted R2 value of linear regression predictive models; all of these statistical measures were statistically significant (all p-values <0.043). One author (VMD), who collected the majority of the data for the Crowder/Dominguez method, also performed interobserver error measures for the Ingvoldstad and Gocha studies, neither of which demonstrated significant differences between observers.
The correlation coefficient for the Ingvoldstad method was R=0.143, and the adjusted R2=0.016, indicating OPD explained only 1.6% of the variation in age-at-death. The correlation coefficient for the Crowder/Dominguez method was R=0.681, and the adjusted R2=0.462, indicating OPD explained 46.2% of the variation in age-at-death. The correlation coefficient for the Gocha Octant method was R=0.907, and the adjusted R2=0.817, indicating OPD explained 81.7% of the variation in in age at death. For the Gocha Quadrant method, the correlation coefficient was R=0.918 and the adjusted R2=0.838, indicating OPD explained 83.8% of the variation in age at death.
Results indicate that ROI size has a significant effect on the ability to predict age-at-death from histological remodeling. Examination of small, isolated ROIs is not recommended, as such an approach is more susceptible to random variation in variable distribution and can negatively affect interpretation. Instead, future studies should examine larger ROIs to maximize histological remodeling’s ability to predict age-at-death.
Papers by Megan E . Ingvoldstad, PhD, D-ABFA
individuals analyzed.
This presentation will impact the forensic science community by demonstrating that the amount of bone sampled/analyzed in histological age assessment can have a profound impact on the ability to accurately estimate age-at-death. This will inform future histological research, resulting in higher quality forensic research and practice.
As a complement to macroscopic aging methods, or when necessary macroscopic elements are damaged/absent, age can be estimated through histological examination of remodeling events in cortical bone. To date, the femoral midshaft has been the most commonly employed site for histological studies; however, a consensus is lacking on how much bone to analyze when quantifying remodeling, as existing methods employ ROIs that differ in size, number, and location.
Recently, histological research at the femoral midshaft has proliferated due to the revival of the Ericksen femur collection as an active resource. The current study is a meta-analysis of three recent studies that provide a unique opportunity to assess the effect of ROI size on the relationship between OPD and age. All three studies analyzed here (Ingvoldstad1, Crowder/Dominguez2, and Gocha3 methods) primarily utilized the Ericksen collection, examined the anterior region of the femur, and quantified remodeling according to the same standard histological definitions.
The Ingvoldstad method examined 200 individuals (97 males, 103 females), aged 30–97 years (average=71 years), all from the Ericksen collection; a fixed ROI size of 3.00 mm2 was used to quantify remodeling at eight anatomical and biomechanical locations around the femoral cortex, though only anterior data are analyzed here. The Crowder/Dominguez method examined 320 individuals (170 males, 150 females), aged 15–97 (average=66 years), 87% of which were from the Ericksen collection. This method used a topographic sampling strategy, separating a 5 mm wide section of the anterior femur into 10 columns and reading every other frame using a Merz reticule; this resulted in an average ROI size of 18.30 mm2, with an average of 9.52 mm2 of bone analyzed. The Gocha method examined only 30 individuals (15 male, 15 female), aged 21–97 years (average=59 years), 83% of which were from the Ericksen collection. This method examined remodeling over the entirety of the femoral midshaft, though only anterior octant and quadrant data are analyzed here; average octant ROI size was 41.82 mm2, average quadrant ROI size was 89.93 mm2.
Statistical analyses were performed in SPSS 23. Kolmogorov-Smirnov tests demonstrated OPD values for all methods to be normally distributed (all p-values >0.070). The relationship between OPD and age was assessed through Pearson’s correlation coefficients, as well as the adjusted R2 value of linear regression predictive models; all of these statistical measures were statistically significant (all p-values <0.043). One author (VMD), who collected the majority of the data for the Crowder/Dominguez method, also performed interobserver error measures for the Ingvoldstad and Gocha studies, neither of which demonstrated significant differences between observers.
The correlation coefficient for the Ingvoldstad method was R=0.143, and the adjusted R2=0.016, indicating OPD explained only 1.6% of the variation in age-at-death. The correlation coefficient for the Crowder/Dominguez method was R=0.681, and the adjusted R2=0.462, indicating OPD explained 46.2% of the variation in age-at-death. The correlation coefficient for the Gocha Octant method was R=0.907, and the adjusted R2=0.817, indicating OPD explained 81.7% of the variation in in age at death. For the Gocha Quadrant method, the correlation coefficient was R=0.918 and the adjusted R2=0.838, indicating OPD explained 83.8% of the variation in age at death.
Results indicate that ROI size has a significant effect on the ability to predict age-at-death from histological remodeling. Examination of small, isolated ROIs is not recommended, as such an approach is more susceptible to random variation in variable distribution and can negatively affect interpretation. Instead, future studies should examine larger ROIs to maximize histological remodeling’s ability to predict age-at-death.
individuals analyzed.