Pronasale Position: An Appraisal of Two Recently Proposed Methods for Predicting Nasal Projection in Facial Reconstruction

This study examines two recently proposed methods for predicting nose projection from the skull, those developed by Stephan et al. (Am J Phys Anthropol 122, 2003, 240) and Rynn et al. (Forensic Sci Med Pathol 6, 2010, 20). A sample of 86 lateral head cephalograms of adult subjects from Central Europe was measured, and the actual and predicted dimensions were compared. Regarding nose projection (the anterior and vertical position of the pronasale), in general, the method of Rynn et al. (Forensic Sci Med Pathol 6, 2010, 20) was found to perform better and with less error variance than the method of Stephan et al. (Am J Phys Anthropol 122, 2003, 240), but the mean difference between the actual and predicted values did not exceed 2.2 mm (6.5% of the actual dimension) in most of the variables tested. The vertical dimensions of the nose were predictable with greater accuracy than the horizontal dimensions. Although the mean error of both methods is not great in practice and thus both methods could be considered to be “accurate,” the real variance of error should not be overlooked.     

Improving Nonmetric Sex Classification for Hispanic Individuals

Current techniques used by forensic anthropologists for the identification of unknown human skeletal remains have largely been created using U.S. Black and White samples. When applied to Hispanics, these techniques perform poorly and can lead to misclassifications; consequently, there is an imperative need for population‐specific standards for Hispanics. This research examines the classification accuracies obtained by the original Walker (Am J Phys Anthropol, 136, 2008) and Klales et al. (Am J Phys Anthropol, 149, 2012) methods for nonmetric sex estimation and provides recalibrated regression equations specifically for Hispanics. Ordinal data were collected for five skull and three pelvic traits from a sample of 54 modern Hispanic individuals. Recalibration of the Klales et al. equation improved accuracy (90.3% vs. 94.1%), while recalibration of the Walker method equation decreased accuracy (81.5% vs. 74.1%), but greatly improved sex bias (22.2% vs. ?7.4%), thereby making the recalibrated equations more appropriate for use with Hispanics.     

Positive Personal Identification of Human Remains Based on Thoracic VertebralMargin Morphology

Abstract: Radiography has long been used by anthropologists to establish positive personal identification of human remains in forensic cases. These methods have been largely ad hoc and depend upon specific congenital or pathological bone markers. Court rulings, such as Daubert and Mohan have, however, pushed the discipline toward more statistically supportable methods of identification. This study describes the use of normal morphological variation of the thoracic vertebrae to identify human remains. Radiographs from healthy, male individuals, aged 18–55 were examined to identify normally varying features of vertebral morphology. The frequency of occurrence of these features was calculated, tested, and found to be stable in the given sample. The frequencies were compared to establish which sets of traits varied independently of one another. Finally, unknown radiographs were compared to known samples to test the applicability of this method in determining positive identification, with 21 of 24 (87.5%) unknown radiographs positively identified.     

Anthropological and radiographic comparison of vertebrae for identification of decomposed human remains

This case study demonstrates the importance of involving an anthropologist in forensic situations with decomposed remains. Anthropological consultation was used in conjunction with the comparison of antemortem and postmortem radiographs to establish positive identification of unknown, decomposed remains. The remains had no traditional identifying features such as fingerprints or dental. Through anthropological analysis, it was determined the decedent was male, between 20 and 23 years at time of death and c. 5'2' tall. This information allowed for a presumptive identification and a request for antemortem radiographs. The missing person was identified comparing the spinous processes of the cervical and thoracic vertebrae between ante- and postmortem radiographs.     

Surgical Sutures as a Means of Identifying Human Remains*

Abstract: The Food and Drug Administration does not require surgical sutures to be tracked by manufacturer, physician, or patient; thereby, surgical sutures have been of little use to forensic practitioners who are tasked with establishing a positive identification with biological evidence. This study demonstrates the investigative process used to pinpoint suture manufacturers by presenting a case where surgical sutures were a distinctive characteristic that aided in the positive identification of skeletal remains. The suture’s manufacturer, construction material and structure, size, and medical use was determined by contacting a local surgical suture and orthopedic implant manufacturer and utilizing publicly available manufacturer websites, which provide catalogs and specific product details. This research was one of many lines of evidence used to establish the positive identification of a 47‐year‐old male.     

Positive Dental Identification Using Tooth Anatomy and Digital Superimposition

Dental identification of unknown human remains continues to be a relevant and reliable adjunct to forensic investigations. The advent of genomic and mitochondrial DNA procedures has not displaced the practical use of dental and related osseous structures remaining after destructive incidents that can render human remains unrecognizable, severely burned, and fragmented. The ability to conclusively identify victims of accident and homicide is based on the availability of antemortem records containing substantial and unambiguous proof of dental and related osseous characteristics. This case report documents the use of digital comparative analysis of antemortem dental models and postmortem dentition, to determine a dental identification. Images of dental models were digitally analyzed using Adobe Photoshop^TM software. Individual tooth anatomy was compared between the antemortem and postmortem images. Digital superimposition techniques were also used for the comparison. With the absence of antemortem radiographs, this method proved useful to reach a positive identification in this case.     

Skeletal Indicators of Stress: A Component of the Biocultural Profile of Undocumented Migrants in Southern Arizona,

The ability of forensic anthropologists in the United States to distinguish the remains of foreign nationals from those of American citizens may be crucial to the identification process. This study adds new criteria for identifying Hispanic foreign nationals in southern Arizona to those previously outlined by Birkby et al. (J Forensic Sci 53, 2008, 29) in the “cultural profile.” Skeletal indicators of nonspecific stress were evaluated in undocumented border crossers (UBCs) at the Pima County Office of the Medical Examiner and in documented American samples. Odds ratios show significant associations between UBC status and the presence of porotic hyperostosis and enamel hypoplasias, which are, respectively, 7.9 and 3 times more prevalent among UBCs. These findings are consistent with disparities in access to adequate nutrition and health care during childhood. In conjunction with context and other biocultural factors, the presence of these conditions should prompt practitioners to consider that unidentified remains may represent foreign nationals.     

Anthropological and Radiographic Comparison of Antemortem Surgical Records for Identification of Skeletal Remains*

Abstract: This case review illustrates the important contributions of forensic archeological methods and forensic anthropological analysis to the identification of found skeletal remains. After reassociation of skeletal remains found in two locations, anthropological analysis provided the basis for a presumptive identification and a request for antemortem medical records. Partial DNA profiles were supportive but not conclusive and antemortem dental records were not available. Comparison of antemortem traumas, skeletal morphology, and surgical artifacts with antemortem radiographs and surgical records led to positive identification of an individual missing for almost a decade.     

Application of Enhanced Point Estimators to a Sample of In Vivo CT‐derived Facial Soft Tissue Thicknesses

Facial approximations based on facial soft tissue depth measurement tables often utilize the arithmetic mean as a central tendency estimator. Stephan et al. (J Forensic Sci 2013;58:1439) suggest that the shorth and 75‐shormax statistics are better suited to describe the central tendency of non‐normal soft tissue depth data, while also accommodating normal distributions. The shorth, 75‐shormax, arithmetic mean, and other central tendency estimators were evaluated using a CT ‐derived facial soft tissue depth dataset. Differences between arithmetic mean and shorth mean for the tissue depths examined ranged from 0 mm to +2.3 mm (average 0.6 mm). Differences between the arithmetic mean plus one standard deviation (to approximate the same data points covered by the 75‐shormax) and 75‐shormax values ranged from ?0.8 mm to +0.7 mm (average 0.2 mm). The results of this research suggest that few practical differences exist across the central tendency point estimators for the evaluated soft tissue depth dataset.     

Soft Tissue Decomposition of Submerged,Dismembered Pig Limbs Enclosed in Plastic Bags*

Abstract: This study examines underwater soft tissue decomposition of dismembered pig limbs deposited in polyethylene plastic bags. The research evaluates the level of influence that disposal method has on underwater decomposition processes and details observations specific to this scenario. To our knowledge, no other study has yet investigated decomposing, dismembered, and enclosed remains in water environments. The total sample size consisted of 120 dismembered pig limbs, divided into a subsample of 30 pig limbs per recovery period (34 and 71 days) for each treatment. The two treatments simulated non‐enclosed and plastic enclosed disposal methods in a water context. The remains were completely submerged in Lake Ontario for 34 and 71 days. In both recovery periods, the non‐enclosed samples lost soft tissue to a significantly greater extent than their plastic enclosed counterparts. Disposal of remains in plastic bags therefore results in preservation, most likely caused by bacterial inhibition and reduced oxygen levels.     

A Validation Study of the Langley et al. (2017) Decision Tree Model for Sex Estimation

Langley et al. (2017) developed a sex estimation decision tree utilizing two traditional cranial traits (glabella and mastoid) and a new trait: zygomatic extension. This study aimed to test the reliability of their zygomatic extension scoring method and validate their sex estimation method. Ordinal score data were collected from 281 male and female U.S. White and Black individuals. The five traditional cranial traits were collected from physical specimens, while zygomatic extension was scored from 3D cranial models. Intra‐ and interobserver analyses carried out on a subsample of 30 individuals indicate good agreement between zygomatic scores. The decision tree correctly sexed 71.5% of the sample, but a strong sex bias (94.2% correct for females, 49.3% correct for males) severely limits the utility of this method. The Walker (2008) and Stevenson et al. (2009) methods produced higher accuracy rates (80.8% and 82.6%, respectively), although these methods also produced sex and ancestry biases.     

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.     

Age estimation by measurements of developing teeth: accuracy of Cameriere's method on a Brazilian sample

Developing teeth are commonly the criteria used for age estimation in children and young adults. The method developed by Cameriere et al. (Int J Legal Med 2006;120:49-52) is based on measures of teeth with open apex, and application of a formula, to estimate chronological age of children. The present study evaluated a sample of panoramic radiographs from Brazilian children from 5 to 15 years of age, to evaluate the accuracy of the method proposed by Cameriere et al. The results has proven the system reliable for age estimation, with a median residual error of -0.014 years between chronological and estimated ages (p = 0.603). There was a slight tendency to overestimate the ages of 5-10 years and underestimate the ages of 11-15 years.     

Computer‐aided Dental Identification: An Objective Method for Assessment of Radiographic Image Similarity*

Abstract: A pilot study evaluated a computer‐based method for comparing digital dental images, utilizing a registration algorithm to correct for variations in projection geometry between images prior to a subtraction analysis. A numerical assessment of similarity was generated for pairs of images. Using well‐controlled laboratory settings, the method was evaluated as to its ability to identify the correct specimen with positive results. A subsequent clinical study examined longitudinal radiographic examinations of selected anatomical areas on 47 patients, analyzing the computer‐based method in making the correct identification based upon a threshold level of similarity. The results showed that at a threshold of 0.855, there were two false negative and two false positive identifications out of 957 analyses. Based on these initial findings, 25 dental records having two sets of full mouth series of radiographs were selected. The radiographs were digitized and grouped into six anatomical regions. The more recent set of films served as postmortem images. Each postmortem image was analyzed against all other images within the region. Images were registered to correct for differences in projection geometry prior to analysis. An area of interest was selected to assess image similarity. Analysis of variance was used to determine that there was a significant difference between images from the same individual and those from different individuals. Results showed that the threshold level of concordance will vary with the anatomical region of the mouth examined. This method may provide the most objective and reliable method for postmortem dental identification using intra‐oral images.     

Forensic or Archaeological Issue: Is Chemical Analysis of Dental Restorations Helpful in Assessing Time Since Death and Identification of Skeletonized Human Remains?

In 2011, small mass grave with completely skeletonized remains was discovered in Belgrade suburb. An eyewitness claimed that skeletons belonged to German soldiers killed in WWII. Anthropologists were engaged to investigate whether the skeletal remains correspond to the indicated German group or represent more recent case requiring court trial. Numerous dental restorations were noticed. Owing to the fact that different dental materials were used in dental practice at certain times, the aim of this study was to explore whether analysis of dental restorations could help in identification and estimation of time since death. Inductively coupled plasma optical emission spectrometry revealed that dental fillings corresponded to copper amalgam, conventional silver amalgam, silicophosphate cement, and zinc phosphate cement. Chemical results combined with anthropological and historical facts suggest that the individuals lived before the 1960s in country with well‐developed dental service at that time. Therefore, chemical analysis of dental fillings was useful to distinguish between skeletal remains that are too old to be of forensic interest and the remains relevant to legal investigations.     

On the applicability of secondary dentin formation to radiological age estimation in young adults

The literature provides linear regression formulas for dental age estimation that is based on radiological two-dimensional measurements of the pulp size. The aim of the present study was to explore whether the previously presented regression formulas could lead to statistically sound results and to appropriate repeatability when applied to young individuals. Orthopantomograms (OPGs) of 44 Austrian individuals, aged between 13 and 24 years, were selected at random. In accordance with the reported method, six teeth on each OPG were chosen to carry out the measurements. Statistical analysis was performed in order to assess the difference between the estimated and the true chronological age. The regression formulas reported by Kvaal et al. (1995) led to a consistent underestimation; the regression formulas reported by Paewinsky et al. (2005) resulted in a constant overestimation of age. The statistical analysis of intraobserver and interobserver variation revealed a variation width below 2%, respectively.     

Auricular Surface Aging: Comparing Two Methods that Assess Morphological Change in the Ilium with Bayesian Analyses

Modern standards in forensic anthropology require rigorous testing and evaluation of methods used for aging skeletal remains. Age estimation has been criticized for bias, inaccuracy, and population specificity; issues which are minimized by the application of Bayesian methodology. Using Bayesian statistics, we compare the Lovejoy et al. (Am J Phys Anthropol, 68, 1985, 15) (original) and Buckberry and Chamberlain (Am J Phys Anthropol, 119, 2002, 231) (revised) auricular surface aging methods. Transition analysis parameters derived from American males (n = 372), in combination with a Thai male (N = 37) informative prior, statistically model age in Portuguese males (n = 221). Cumulative binomial tests assess the accuracy of the generated age ranges. Overall, the application of transition analysis and Bayesian statistics significantly improved age estimation with both methods (also outperforming Suchey‐Brooks pubic symphysis aging). Moreover, the accuracy of the original method was low without statistical modeling, whereas the revised method can be applied accurately without further statistical analysis. Additionally, reference tables for aging Portuguese males are provided.     

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.     

Vertical Lip Position and Thickness in Facial Reconstruction: A Validation of Commonly Used Methods for Predicting the Position and Size of Lips

This study examined several methods used to estimate oral fissure position, lip margin position, and lip thickness recommended by Angel, George, Lebedinskaya, Taylor, Wilkinson et al., Balueva and Veselovskaya. A sample of 86 lateral head cephalograms of adult subjects from central Europe were measured and the actual and predicted dimensions were compared. The best estimation for oral fissure position was “opposite the lower ¾ mark of maxillary incisors” (error of 1.3 mm). Upper lip margin was predicted best by “upper ¼ mark of maxillary incisors” (error of 1.7 mm), and lower lip margin by “cementum‐enamel junction of mandibular incisors” (error of 2.3 mm). The regression equations of Wilkinson et al. displayed least error (1.3 mm and 1.8 mm, respectively) for upper and lower lip thickness, and method of George (error of 3.4 mm) for total lip thickness.     

Investigation of homicides interred in concrete--the Los Angeles experience

Decedents interred in concrete present unique problems and investigation of these deaths necessitates a team of forensic specialists. The Los Angeles County Department of Coroner has had five such deaths in the past 18 years. The buried cases needed layer-by-layer excavation to establish the time and cause of death. Metal detectors are often used in this process. X-rays of the interred remains were completed to help with locating the decedent's position in the concrete. The breaking of concrete in some of the cases required the use of a sledgehammer and later a chisel in a manner that would not damage the remains. Postmortem dismemberment was frequent in our cases. The decedents were all female or prepubescent children, and the perpetrators were closely related to the decedents. While concrete can interfere with determination of postmortem interval, it can also preserve the remains and assist with identification.