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.     

Personal identification by radiographic comparison of vascular groove patterns of the calvarium

A case of forensic identification utilizing the vascular grooves within the skull is presented. The case is unique in that the antemortem radiographs were from childhood, rendering useless the more standard points of comparison. Calvarial vascular grooves represent unique points of comparison when the only available premortem radiographs were obtained during childhood, especially when one is attempting to identify children (living or dead).     

Personal identification based on radiographic vertebral features

Personal identification of human remains constitutes about 10% of the normal caseload of any forensic medicine practice. Identification can be achieved by a variety of methods, one of which is the comparison of antemortem and postmortem radiographs. There are numerous accounts of cranial and dental radiographic features useful for identification, whereas the availability of postcranial radiographs and especially plates that depict the vertebral column is less widespread among the forensic community. The authors here review the various vertebral features instrumental in positive identification that can be identified on radiographs of the spine.     

Comparative dental radiographic identification using flat panel CT

A skull without lower jaw was found and brought in for identification. It was suspected to be that of a man reported missing five years ago. An undated antemortal dental chart and two dental films of the 1st and 2nd dental quadrants, both taken about 4 years before the man went missing, were available for comparison. The method of choice in solving the identity question was comparative dental radiography. Despite numerous attempts, it was not possible to obtain radiographs of the upper jaw that duplicated the X-ray beam angulation of the antemortem dental films. The skull was thus scanned with a multislice computed tomography (MSCT) scanner, and virtual radiographs with the desired angulation were generated from the data with the maximum intensity projection (MIP) technique. The resulting virtual radiographs could, however, not be used for superimposition with the antemortem radiographs because of their poor resolution and the occurrence of artifacts caused by metallic dental fillings. The upper jaw was therefore scanned again, this time with a high resolution eLU-CT (eXplore Locus Ultra flat panel CT). The resulting eLU-CT datasets were visualized with the MIP technique and yielded virtual radiographs that could be compared with the antemortem radiographs. Positive identification could be assumed with near certainty after dental features could be matched in the superimposition of antemortem and postmortem radiographs. In the presented case, eLU-CT was used for the first time for a comparative dental radiographic identification.     

Identification of a skeleton using DNA from teeth and a PAP smear.

Identification of unknown living or deceased persons using dental treatment records is an established forensic technique. However, some cases remain unidentified, especially when antemortem dental records are not available for comparison to postmortem dental records. Cytological smears have been previously reported to be potential sources of DNA reference samples which can be compared to DNA recovered from found human remains. The case described here involves an adult skeleton which exhibited extensive, complex dental restorative treatment. A putative identification of the found skeleton as a missing woman was established using circumstantial evidence found at the scene. However, it became important to establish a positive identification using reliable scientific methods. When it was discovered that antemortem dental records were not available because the treatment was completed in another country and the treating dentist could not be found, cytological smears stained with Papanicolaou (PAP) stain obtained from the putative decedent's medical records were used as a reference DNA sample. DNA was recovered from the teeth of the skeleton using cryogenic grinding. Comparison of the genotypes resulted in the conclusion that the DNA originated from the same source. The use of PAP smears in this way is seen as a valuable resource in cases where positive identification using traditional dental and medical records is not possible.     

Shadow positioning technique: a method for postmortem identification

Radiology is increasingly being used as a means of postmortem identification. We have devised a shadow positioning technique by which a postmortem radiograph of a skeletal part can exactly duplicate an antemortem radiograph, thus, faciliating identification by comparison of the antemortem and postmortem radiographs. The antemortem radiograph can be of any skeletal part and taken in any position.     

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.     

Validation of chest X-ray comparisons for unknown decedent identification

Comparing skeletal structures between antemortem and postmortem chest radiographs is widely used by forensic specialists from many disciplines to positively identify unknown decedents. However, validity assessments of this method have been fairly limited. This study had three objectives: 1) to quantify the reliability of ante- and postmortem chest radiograph comparison for decedent identification; 2) to identify useful radiologic features supporting decedent identification; and 3) to recognize sources of error in decedent identification related to use of comparative radiographs. A forensic pathologist, a forensic anthropologist, and two radiologists participated in the study. Our results showed that chest radiograph comparisons proved reliable, if basic decedent information was provided, and antemortem and postmortem radiographs were adequately positioned and exposed. A "morphological approach" using normal anatomical structures for comparison may provide the most efficient method for accurate identification.     

The use of thoracolumbar and hip joint dysmorphism in identification

A case of roentgenographic identification of a deceased person is presented. Comparison of antemortem and postmortem radiographs of the vertebral column and hip joint, for the purpose of identification, was based on the deceased medical history, and the fact the deceased was endentulous, and fingerprint comparison was not feasible. Evaluation of anatomical variants, due to the effects of degenerative disease, provided positive identification in a visually unidentifiable deceased person.     

Role of orthopedic implants and bone morphology in the identification of human remains

When conventional methods of identification, such as visual recognition and dental comparison, cannot be used to identify a deceased person, it becomes necessary to consider alternative methods. The presence of an orthopedic implant in a body may assist identification if ante-mortem medical records are available for comparison. Another method of identification involves comparison of ante-mortem and postmortem radiographs. Eight cases are reported from Forensic Science SA where the presence of orthopedic implants and/or ante-mortem radiographs were used to try to establish identification. In six cases, positive identification was established, and in two cases with upper limb orthopedic implants, the bones remained unidentified. Manufacturers were unable to provide any information about the distribution and use of the implants that could be of use with identification, as there are no requirements in Australia for individual medical implants to be tracked. Such a system has the potential to aid postmortem identification if serial codes were etched onto implants that could then be traced to manufacturers, surgeons, and recipients of these devices.     

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.     

A Radiographic Study on the Utility of Cranial Vault Outlines for Positive Identifications

A standard method for positive identification is the use of antemortem and postmortem radiographic comparisons. The purpose of this research is to test the visual accuracy of antemortem and postmortem radiographic comparisons of cranial vault outlines and to evaluate their uniqueness using geometric morphometric methods. A sample of 106 individuals with varying levels of education and forensic case experience participated in a visual accuracy test. Of the 106 individuals, only 42% correctly assigned all of the radiographs, with accuracy rates ranging from 70 to 93% for each radiographic comparison. Vault shape was further examined using elliptic Fourier analysis, and paired t‐tests were computed on the first 10 principal components accounting for 100% of the variance, which found no significant differences. The visual accuracy test and elliptic Fourier analysis shows that vault outlines may not be unique enough for positive identifications when used as a sole indicator.     

Methods for identification of 28 burn victims following a 1996 bus accident in Spain

A car collided head-on with a bus containing 56 passengers plus the driver. A few seconds after the crash, the bus caught fire and 28 persons (15 male and 13 female) lost their lives. All the deceased were almost completely incinerated. To establish the identity of the victims, the judge in charge of the case designated a multidisciplinary Identification Commission. Postmortem procedures included a general external examination, routine photographs, dental examination, dental (intraoral and extraoral) and general radiographs (chest, ankle, etc.), and complementary biological methods for identification (e.g., DNA analysis). The antemortem information, including dental and medical records available, were transcribed onto the INTERPOL disaster victim identification forms. The detailed ante- and postmortem information were compared manually. In this disaster dental identity could be established in 57% of the victims, whereas dental evidence did not allow by itself the identification of 12 burned victims. Odontological examination and complementary radiographic procedures were found to be accurate, economic and rapid methods of identifying badly burned victims in this bus accident.     

Identification of unknown human remains by comparison of antemortem and postmortem radiographs

The identification of unknown human remains by comparison of ante mortem and post mortem radiographs has found wide acceptance in recent years. This report documents two recent cases in Hong Kong in which unequivocal positive identifications were achieved by comparison of radiographs. In both cases, comparison of radiographs was the only available means of establishment of personal identity. The first case involved the identification of a very badly burned body of a 22-year-old male by the matching of the ante mortem and post mortem radiographic images of the cranial base (in particular the sella turcica), hard palate, paranasal air sinuses, mastoid air cells, the lambdoid suture, and the upper molar teeth as revealed on comparable lateral skull films. The second was the identification of a deliberately mutilated torso of a 28-year-old female by comparison of the radiographic images of the lumbar spine, pelvis, and head of the femur as revealed on plain abdominal films taken before and after death. While evidence of injury or surgery did not figure in either of the identifications, the presence of a mild scoliosis and the absence of the twelfth ribs aided identification in the latter case. Emphasis is placed in this account on the value of radiographic comparison as a means of identification because it draws upon the matching of intricate and highly individual patterns of external and internal bony anatomy that are stable over long periods of time. In cases where ante mortem radiographs and photographs are available, establishment of personal identity by comparison of radiographs is deemed preferable to identification by photographic superimposition because radiographic comparison permits the matching of a potentially larger number of unique anatomical features and is less time consuming and technically exacting.     

Reconstruction of root morphology in skeletonized remains with postmortem dental loss.

A reversible technique is presented in which the root morphology of missing teeth in skeletonized human remains can be reconstructed for the purpose of radiographic comparison and postmortem identification. In this technique, which is based upon pilot studies with skeletonized mandibles of archival remains, the alveolar socket walls are sealed with a coat of cyanoacrylate cement and injected with a mixture of vinyl polysiloxane and barium sulfate. Radiographs are produced with the radiopaque mixture in place, which highlights the antemortem morphology of the roots. Subsequently, the impression material is removed, resulting in no gross alteration of the evidence. The radiographs made with this technique, as well as the impressions, can be stored for later use at a trial or pending the discovery of antemortem dental evidence.     

Identification of the Edentulous Individual: An Investigation into the Accuracy of Radiographic Identifications*

Abstract: The dental identification of edentulous individuals can be challenging based on the lack of antemortem materials and unique features visible on radiographs. The constant resorption of the alveolar ridges further complicates the process. The purpose of this study was to quantify the error rate and reliability of dental identifications based on a comparison of synthesized antemortem and postmortem radiographs of edentulous individuals. Ten observers examined ten cases on two occasions and reported dichotomous and conclusion level decisions. These were analyzed using Kappa and Receiver Operator Characteristics. The mean area under the curve was 0.75 and the mean sensitivity was 0.57 and specificity was 0.83. These results suggest that dental identifications of edentulous individuals using radiographs alone have a high error rate and should be dual reported. These data add further weight to the argument that all dental prostheses should be labeled.     

医学影像资料法医学同一认定30例分析

目的探讨医学影像资料法医学同一认定的鉴定原则、思路及方法。方法总结华西法医学鉴定中心1992—2012年受理的30例医学影像资料同一认定案例,对影像资料数量、种类,鉴定利用的识别点及其类型、间隔进行回顾性统计分析。结果胸部X线片为最常见的鉴定资料类型。利用的识别点共有33处、6种类型,包括：自身惟一性特征、骨骼自身结构的变异或发育畸形、疾病或退行性变、创伤后病理变化、医疗后果和正常形态的多处一致。结论影像资料常规审查是案件受理前提之一,同一认定时结合资料类型、投照部位及案情特点选择相应识别点,自身惟一性识别点最佳,多种类型识别点联合使用,识别点多处表现一致得出肯定结论者可应用于鉴定实践。     

Morphometric Comparison of Clavicle Outlines from 3D Bone Scans and 2D Chest Radiographs: A Shortlisting Tool to Assist Radiographic Identification of Human Skeletons

This paper describes a computerized clavicle identification system primarily designed to resolve the identities of unaccounted‐for U.S. soldiers who fought in the Korean War. Elliptical Fourier analysis is used to quantify the clavicle outline shape from skeletons and postero‐anterior antemortem chest radiographs to rank individuals in terms of metric distance. Similar to leading fingerprint identification systems, shortlists of the top matching candidates are extracted for subsequent human visual assessment. Two independent tests of the computerized system using 17 field‐recovered skeletons and 409 chest radiographs demonstrate that true‐positive matches are captured within the top 5% of the sample 75% of the time. These results are outstanding given the eroded state of some field‐recovered skeletons and the faintness of the 1950's photofluorographs. These methods enhance the capability to resolve several hundred cold cases for which little circumstantial information exists and current DNA and dental record technologies cannot be applied.     

Video superimposition at the C.A. Pound Laboratory 1987 to 1992.

William R. Maples practiced many aspects of human identification using simple and relatively inexpensive video superimposition equipment. Identification of skulls by comparison to known photographs was a primary concern. Clear, smiling photographs revealing the spatial relationships of the teeth to one another led to uncomplicated positive identifications. However, without benefit of dentition, how accurate was an identification based on the alignment of soft tissues with the underlying skull? Most importantly, how often would a false positive result when anterior dentition were not available? A study conducted by this author and Dr. Maples used three human heads and 98 profile and full-face photographs. A 0.6% incidence of false match resulted when both views of the face were used. Lateral view and frontal view superimpositions were identified incorrectly in 9.6% and 8.5% of the sample respectively. As a result, multiple photographs from varying angles were requested for superimposition identity cases. Additional applications in laboratory case work were developed for the equipment. Light boxes under the television cameras allowed radiographic comparisons. Video taped comparisons of antemortem and postmortem radiographs were shown to medical examiners and families as proof of identification. Dr. Maples and this author were also involved in several cases in which photographs taken by a surveillance or ATM camera were compared to court ordered photographs of an alleged perpetrator. One case, which went to trial, led to the conviction of a habitual criminal under Florida statute. This individual had a condition known as Stahl's ear, a deformation of the cartilaginous structure. The ear was seen clearly in many of the ATM camera photographs and was aligned easily with the known photographic sample.     

Digital dental radiographic identification in the pediatric, mixed and permanent dentitions.

The purpose of this paper is to investigate the utility of digital dental radiographic superimposition in the various stages of development of the human dentition. Digital, computer assisted dental identification is a means of identification which allows the spatial relationships of the root and support structures of the teeth to be compared one to the other. The technique has not been tested in patients with developing dentitions. Dental radiographs from patients in the pediatric, mixed and permanent dentition stages of development, simulating "antemortem" and "postmortem" radiographs, were digitized using a flat field radiograph scanner. Anatomic features were used as points of comparison utilizing image editing software whereby anatomic sections were digitally cut from the antemortem image and compared to the same anatomic locations on the postmortem image to assess for points of concordance. The technique was applied to 25 cases within the primary dentition, 25 cases within the mixed dentition and 25 cases within the permanent dentition. Results showed that this was a viable technique within both the pediatric and permanent dentition although it was of little value within the mixed dentition.