The Automation of Regression Modeling in Osteometric Sorting: An Ordination Approach

This study compares the original osteometric sorting association method with an ordination approach across all combinations of the humerus, ulna, radius, femur, tibia, and fibula. This includes both the original prediction interval and t‐statistic approaches. Standard measurements are utilized in the models with full measurements combined and without length measurements. The sample is the osteometric sorting reference from the Defense POW/MIA Accounting Agency. A full set of performance statistics is provided. Results indicate the ordination approach outperforms the original in the majority of bone combinations. Models with length measurements have more exclusion power than those without. It is recommended for the ordination approach to supersede the original when applied to large commingled assemblages.     

An Analysis on the Choice of Alpha Level in the Osteometric Pair‐matching of the Os Coxa,Scapula, and Clavicle

This study compares the use of 0.05 and 0.10 alpha levels with the updated osteometric pair‐matching model on two samples of the os coxa, scapula, and clavicle. The samples include the Forensic Data Bank, and the osteometric sorting reference used within the Defense POW/MIA Accounting Agency. Mixed‐effects two‐way analyses of variance were used to analyze bilateral asymmetry in the standard measurements. In total, 3,793,566 t‐tests were conducted for osteometric pair‐matching analysis. The results indicate high levels of exclusion power, and accuracy can be obtained with the os coxa and scapula. The clavicle standard measurements capture too much asymmetry causing a lower exclusion to accuracy ratio for osteometric pair‐matching relative to other elements. Both 0.05 and 0.10 alpha levels provide acceptable levels of performance. A lower alpha level will result in higher accuracy with less exclusion, and a higher alpha level will result in lower accuracy with more exclusions.     

Z‐Transform Method for Pairwise Osteometric Pair‐matching,

A new pairwise osteometric pair‐matching approach based on the Z‐transform method is presented. In contrast to previous methods that perform a global t‐test on the summed skeletal element pair measurement distances, this approach performs t‐tests on each individual distance, facilitating the capture of measurement‐specific variation. This new approach is compared to published pairwise sorting methods using a standard reference dataset of postcranial remains maintained by the Defense POW/MIA Accounting Agency. Receiver operating characteristic curve analysis indicates significantly improved performance for the clavicle and radius over all previous methods (p < 0.01). The z‐transform method weighted by the effect size outperformed the t‐test (Byrd and Adams) and the mean t‐test (Lynch) for all elements (p < 0.01). The method performed better than the absolute value t‐test (Lynch) for five elements (p < 0.01) and performed at least as well for the remainder. To facilitate usability all methods are available at: https://github.com/spawaskar-cora/z-transform-method .     

Reanalysis of the Trotter Tibia Quandary and its Continued Effect on Stature Estimation of Past‐Conflict Service Members

Forensic casework from past‐conflicts relies on the corrected historical Trotter data for stature estimation in Fordisc. For roughly 10 years’, stature estimation using this data has produced point estimates for the tibia that are on average 1.25 inches less than the other long bones. This issue was identified after applying the equations derived from Fordisc to the USS Oklahoma commingled assemblage. Reevaluation of Fordisc revealed that a correction factor of 20 mm, instead of 10 mm, was mistakenly applied to the Trotter tibia data. Historical forensic anthropology reports written at the Defense POW/MIA Accounting Agency were utilized to identify that the overcorrection is isolated to Fordisc 3 with an error rate of 5% of known antemortem statures falling outside of the prediction intervals that relied on the tibia. Further evaluation of the Oklahoma sample indicates the 10 mm correction is still producing point estimates less than the other long bones.     

A Test of Age Estimation Methods on Impacted Third Molars in Males

This study tests the relationship between third molar impaction and its concomitant effect on age estimation methods. Data were collected on radiographs of males analyzed in the Defense POW/MIA Accounting Agency Laboratory (n = 114). Radiographs of skeletonized individuals were scored for dental development, and age was assigned based on the appropriate ancestry‐based method. Differences between identified age and estimated dental age were assessed to determine whether molar impaction affected root development and age estimations. Results indicate that impacted teeth tend to be underdeveloped and result in age estimates that are too low. While these results are of note to anthropologists and odontologists performing dental age estimates, more work is needed to explore the effect of impaction on development among a more diverse sample.     

Generating a Vertebrae‐based Method to Discriminate between Korean and U.S. White Male Casualties from the Korean War,

Low recovery rate of intact crania in conflict‐related contexts necessitates the use of postcranial elements for ancestry estimation. This study aimed to develop a new method to discriminate between Korean and U.S. White casualties from the Korean War using vertebrae. Maximum body heights of C2 through L5 were measured from 75 Korean and 51 U.S. males to generate discriminant functions. U.S. vertebral heights were statistically greater than Koreans in 18 out of 23 vertebrae (C2, C4‐6, T3‐6, and T8‐L5). The functions with lumbar vertebrae tended to yield higher correct classification ratios (CCR) than those with cervical or thoracic vertebrae. Inclusion of the femur and tibia lengths in the vertebrae‐involved functions enhanced the CCR's. Discriminant functions using the femur and tibia length were also presented. The results of this study are expected to complement the current practices of the Defense POW/MIA Accounting Agency and the Ministry of National Defense Agency for KIA Recovery and Identification, which are primarily based on cranial and dental morphology.     

Getting Ahead: Extraction of DNA from Skeletonized Cranial Material and Teeth

Between 1990 and 2018, the Defense POW/MIA Accounting Agency submitted 2177 cranial elements and 1565 teeth to the Armed Forces Medical Examiner System—Armed Forces DNA Identification Laboratory for DNA testing. In an effort to identify missing United States service members, materials were recovered from wartime losses inclusive of World War II, the Korean War, and Southeast Asia. Using four different DNA extraction protocols, DNA testing was performed using mitochondrial DNA Sanger sequencing, modified AmpFlSTR^® Yfiler?, AmpFlSTR^® MiniFiler?, PowerPlex^® Fusion, or Next Generation Sequencing. This paper aims to provide optimal strategies for the DNA testing of skeletonized cranial materials. Cranial elements produced the most consistent results in Sanger sequencing using an organic purification; however, teeth were most successful for the same platform with an inorganic purification. The inverse is true for STR testing of cranial bones. Of the cranial elements, the temporal provided the most consistent results.     

The Importance of Blind Forensic Odontology Analyses

Forensic odontology cases examined from 2012 to 2019 at the Defense POW/MIA Accounting Agency (DPAA) laboratory were reviewed. Five cases from World War II and the Korea War were selected. Three of the cases presented involve dental assemblages, which were built by previous analysts. Postmortem radiographic analyses at the DPAA laboratory of these cases were complicated by the use of an older version of a digital x-ray program and the assumption that teeth placed in the parent bone (maxilla and mandible) did not fully articulate due to the presence of debris at their root apices. Conflicting mitochondrial DNA test results for the submitted teeth and previously believed to be parent bone indicated these elements were not from the same individual. The remaining two cases are examples of how knowledge of findings from other disciplines may sway an opinion and could possibly lead to the rendering of erroneous opinions by the forensic odontologist. Having knowledge of previous examinations or results from other scientists, disciplines, and lines of evidence may lead to a bias in findings or opinions. If not careful, even the best-intended scientist may fall victim to a bias in their opinion/analysis. The forensic odontologist should perform all analysis in the blind, not knowing any information which may bias their opinion, and utilize current versions of digital x-ray software available and their tools when performing their examinations.     

Proposed Method for Predicting Pair Matching of Skeletal Elements Allows Too Many False Rejections

Byrd proposes a method for predicting pair matches in commingled remains to reduce visual comparison. The method compares differences between left and right postcranial element measurements in commingled samples with differences in known pairs from a reference sample using a t‐score approach. We duplicated his protocol using six elements from two samples of known paired elements (n = 854 to 1063) and calculated the number of pairs correctly predicted. Time commitment was estimated by mathematically attempting matches with all left and right elements in these samples. Although the results show an 86% reduction in the number of potential pairs requiring visual matching, we do not recommend the method because (i) the normality assumption for use of a t‐score approach is violated, (ii) no account is made for bilateral asymmetry, and (iii) the high rate of false rejections (up to 22%) undermines its ability to show true incompatibilities for potential pair matches.     

A Retrospective Review of Forensic Odontology Reports Written by the Joint POW/MIA Accounting Command Central Identification Laboratory for Remains Identified from the Korean War

As of August 2014, the Joint POW/MIA Accounting Command has identified the remains of 1980 previously unknown U.S. service members; 280 were from the Korean War. To determine the accuracy and completeness of the available antemortem (AM) dental records, a review of the AM/postmortem (AM/PM) dental record comparisons from 233 Forensic Odontology Reports written in support of remains identified from the Korean War was performed. Seventy‐two AM/PM comparisons resulted in exact dental chartings while 161 contained discrepancies which were explainable. Explainable discrepancies include undocumented treatment (103), incorrectly charted third molars as missing (82), differing opinions of specific molars present/missing (20), and erroneous treatment documentation and/or misidentification of teeth present/missing (22, other than molars). Reassessment has revealed varying levels of completeness for our available AM dental records, the need to thoroughly review our computerized comparisons, adjust our comparisons to include molar pattern variations/third molars, and updating our database comparison program.     

A novel method for sorting and reassociating commingled human remains using deviation analysis

This study provides an innovative and novel method for sorting commingled human remains at the sacroiliac joint using deviation analyses. Virtual models were created at the University of Tennessee-Knoxville Donated Skeletal Collection from 69 os coxae and 66 sacra using an EinScan-Pro 2× + Handheld Surface Scanner. The shape of the auricular surfaces was analyzed in Geomagic Wrap 2017, and the congruency of the two auricular surfaces was measured using a deviation analysis. ROC curves were performed on a reference sample composed of 200 commingled and non-commingled joint pairs to identify threshold values that could help sort the commingled remains. A validation sample of 225 pairs was subsequently analyzed to demonstrate the efficacy of this new method on a sample of unknown individuals. Statistical analyses demonstrated that the deviation analysis values from sacroiliac joints of commingled pairs were significantly larger than those from non-commingled individuals (p < 0.0001). Based on the selected threshold values, 98%–100% of pairs were correctly sorted and reassociated. This novel and objective technique improves upon previously subjective strategies for sorting commingled remains and, in the future, will be applied to additional joint surfaces.     

A Reliable Regression‐Based Approach for Reassociating Human Skeletal Elements of the Lower Limbs from Commingled Assemblages

Accurate sorting of commingled human remains comprises a fundamental requirement for all further anthropological analyses. The lower limb bones are particularly important for reconstructing biological profiles. This study introduces a metric technique for sorting these elements using eight standard anthropological measurements and 222 adult individuals from Greece. The bones utilized were the os coxae, the femora, the tibiae and the tali. Simple regression analyses were used to develop functions for reassociating articulating bones, providing strong correlations (r = 0.74–0.95, p‐value <0.05) and high coefficients of determination (r²=0.54–0.91). Blind tests demonstrated that combining metric and morphoscopic techniques provides an excellent sorting accuracy for the hip and knee joints (ten of ten individuals), allowing for a reliable reassociation between a sex and age indicator (os coxae) and a body size indicator (femur). Overall, these results indicate the high value of metric methods in sorting commingled human remains.     

Measuring the intercondylar shelf angle using radiographs: intra- and inter-observer error tests of reliability

This study presents a test of intra- and inter-observer measurement error rates of the intercondylar shelf angle of the distal femur, as measured on lateral radiographs. This measurement is the central element of a method to determine racial affiliation from the distal femur. Four observers independently radiographed a set of 33 complete and partial femora from collections housed at the Joint POW/MIA Accounting Command, Central Identification Laboratory. Each observer then measured the intercondylar shelf angles in each radiograph, following the original method's guidelines. A supplementary inter-observer error test was conducted by four additional observers on one set of radiographs. Statistically significant differences were found for both intra- and inter-observer error based on the results of Student's t-tests, paired samples t-tests, and ANOVA analyses. The results of this study indicate that further experimentation should be undertaken in order to develop refined measurement techniques that may help improve standardization and reduce the observer error rates.     

Field Contamination of Skeletonized Human Remains with Exogenous DNA

The Armed Forces DNA Identification Laboratory reports the mitochondrial DNA (mtDNA) sequences of over 800 skeletal samples a year for the Joint POW/MIA Accounting Command–Central Identification Laboratory. These sequences are generated from degraded skeletal remains that are presumed to belong to U.S. service members missing from past military conflicts. In the laboratory, it is possible to control for contamination of remains; however, in the field, it can be difficult to prevent modern DNA from being transferred to skeletal elements and being carried forward through the analysis process. Four such cases are described here along with the controls in place in the laboratory to eliminate the possibility of the exogenous DNA being reported as authentic. In each case, the controls implemented by the laboratories prevented the false reporting of contaminant exogenous DNA from remains that were either faunal or human, but lacked endogenous DNA.     

Use of 2D:4D Digit Ratios to Determine Sex

Second to fourth digit ratios (2D:4D) are sexually dimorphic in human hands and established by the 13th gestational week. Application of 2D:4D for determining sex in living individuals by Kanchan et al. (Forensic Sci Int, 181, 2008, 53.e1) produced classification rates of 80% for males and 74–78% for females. Few studies have explored the use of 2D:4D for sexing skeletal remains. We test estimated finger lengths, phalanx lengths, and 2D:4D derived from hand bones for determining sex. Maximum phalanx length was collected using a mini‐osteometric board from 451 individuals of known age, sex, and ancestry in four skeletal collections. Logistic regression of 2nd and 4th digit finger and phalanx lengths produced classification rates greater than 80%. Digit ratios, however, failed to reach classification rates greater than 59%. Our results support those of Voracek (Forensic Sci Int, 185, 2009, e29) and suggest that 2D:4D may be population‐specific and thus inappropriate for universal application as a means of determining sex.     

The Analysis of a World War I U.S. Service Member's Dental Remains Recovered in France

In October 2009, the grave of an unknown World War I (WWI) U.S. service member was exhumed in Rembercourt‐Sur‐Mad Village, in the Lorraine Region of France. The skeletal remains and material evidence were accessioned into the Joint POW/MIA Accounting Command's (JPAC) Central Identification Laboratory (CIL). The personnel records for the associated casualty were requested, received, and reviewed. A dental profile was present among the service member's personal information. There were multiple points of concordance between the dental records of the associated casualty, and the recovered dental remains to include eight restored teeth, 15 unrestored teeth, and three antemortem missing teeth. Distinctive restorations which compared favorably included a porcelain crown and multiple gold foil fillings. All lines of evidence (historical, material evidence/personal effects, anthropological, and dental) and the circumstances of loss compared positively with the associated casualty. On April 1, 2010, the previously unaccounted‐for U.S. service member was positively identified and on June 23, 2010, was buried with full military honors at Arlington National Cemetery.     

DNA Identification of Commingled Human Remains from the Cemetery Relocated by Flooding in Central Bosnia and Herzegovina

The floods in Bosnia and Herzegovina in May 2014 caused landslides all over the country. In the small village of ?eri?i, near the town of Zenica, a landslide destroyed the local cemetery, relocated graves, and commingled skeletal remains. As the use of other physical methods of identification (facial recognition, fingerprint analysis, dental analysis, etc.) was not possible, DNA analysis was applied. DNA was isolated from 20 skeletal remains (bone and tooth samples) and six reference samples (blood from living relatives) and amplified using PowerPlex^® Fusion and PowerPlex^®Y23 kits. DNA profiles were generated for all reference samples and 17 skeletal remains. A statistical analysis (calculation of paternity, maternity, and sibling indexes and matching probabilities) resulted in 10 positive identifications. In this study, 5 individuals were identified based on one reference sample. This has once again demonstrated the significance of DNA analysis in resolving the most complicated cases, such as the identification of commingled human skeletal remains.     

Multimethod Resolution of a Small‐Scale Case of Commingling

This study highlights the use of multiple methods for resolving a case of commingled human remains. Skeletal remains were located in a marijuana field in rural northern California by law enforcement. Although initially buried in shallow graves, the remains of two decedents were disturbed by large carnivores and scattered over a wide area. The remains were submitted by law enforcement for forensic anthropological analysis and resolution of commingling. To segregate the remains of the two individuals, a number of methods were employed, including: (i) physical matching of fragmented remains; (ii) articulation to evaluate joint congruence; (iii) visual pair‐matching of bilateral elements; (iv) osteometric pair‐matching; (v) evaluation of taphonomic patterns; (vi) DNA analysis; and (vii) portable X‐ray spectrometry (pXRF). This multimethod approach resulted in accurate resolution of the commingling and facilitated reconstruction of the biological profiles, taphonomic patterns, and trauma analysis for each individual.     

Validation of the New Interpretation of Gerasimov's Nasal Projection Method for Forensic Facial Approximation Using CT Data,

The most common method to predict nasal projection for forensic facial approximation is Gerasimov's two‐tangent method. Ullrich H, Stephan CN (J Forensic Sci, 2011; 56: 470) argued that the method has not being properly implemented and a revised interpretation was proposed. The aim of this study was to compare the accuracy of both versions using a sample of 66 postmortem cranial CT data. The true nasal tip was defined using pronasale and nasal spine line, as it was not originally specified by Gerasimov. The original guidelines were found to be highly inaccurate with the position of the nasal tip being overestimated by c. 2 cm. Despite the revised interpretation consistently resulting in smaller distance from true nasal tip, the method was not statistically accurate (p > 0.05) in positioning the tip of the nose (absolute distance >5 mm). These results support that Gerasimov's method was not properly performed, and Ullrich H, Stephan CN (J Forensic Sci, 2011; 56: 470) interpretation should be used instead.