From Volume 50, Issue 7, July 2023 | Pages 600-607
Antemortem photographs can be useful for forensic odontology purposes. Five case studies demonstrate how antemortem photographs (including selfies and dental intra-oral photographs) and 3D scans have been used successfully in human identification. evidence, implementation is limited in the UK, and this appears to be due an inconducive political environment, although this is improving.
Identification using dental records is an efficient, reliable and economical procedure. Odontology is a primary identifier, so can be used alone or in combination with other means of identification to establish the identity of an individual.1,2 Forensic odontology frequently relies upon dental restorations and site of the teeth present. However, historically forensic odontology seldom uses all of the information available about the teeth and jaws, including size and shape of teeth and arches, and the intra and inter-arch relationships of teeth and jaws. Identification using odontology is dependent on the presence of adequate dental remains, and on the availability and quality of antemortem (AM) dental records.3 Dental records should be accurate and the dental chart is one of the fundamental components of dental records; however, one audit of more than 1000 dental charts from general dental practice in the UK revealed that 44% were incorrect.4,5 Forensic odontologists will use all available elements of the dental records whenever possible, including clinical notes and radiographs, and if available photographs, laboratory slips, referral letters, models, orthodontic appliances, mouth guards, occlusal splints and bleaching trays.6,7 Radiographs, photographs and study models capture the dentition reliably at a given point in time, and when available in the dental records, they may prove to be invaluable for an odontologist. Even photographs of the smile that have not been taken by the dental team may be a reliable source of AM information with the potential to help solve certain cases of human identification.8 Forensic odontology case studies in the literature have described the comparison between a 2-dimensional (2D) AM photograph and a 2D post-mortem (PM) photograph.8,9,10,11,12,13,14,15,16,17 With the advent of 3-dimensional (3D) technology, further opportunities have arisen for different methodologies of forensic comparison to support a forensic odontology conclusion in human identification.18,19,20
With any forensic odontology case, a conclusion should be recommended to HM Coroner/Procurator Fiscal at the earliest opportunity.7 HM Coroner will then review all the evidence available to them, including the forensic odontology report, and establish the identity of the person who has died, how when and where the deceased came by his or her death, and any information required by the Births, Deaths and Registrations Act, 1953 to be registered concerning the death.21
The five recent cases presented here demonstrate the following:
A PM dental chart was compiled at the PM dental examination. Recent AM dental records had been obtained from the dental practice and appeared to be complete. AM records included computerized written entries, a computerized chart and two intra-oral photographs. The PM and AM dental charts differed (Figure 1). At PM, six teeth had amalgam fillings, seven teeth had composite fillings, three teeth had a veneer and two teeth had a crown. The AM chart recorded five teeth with composite fillings, four teeth with veneers and two teeth with a crown (Figure 1). The AM chart did not record any amalgam fillings.
The AM intra-oral photographs from the GDP (Figure 2a, c) recorded features that were comparable to the findings at PM. PM photos were taken at the PM dental examination (Figure 2b, d) and common features were highlighted. While similarities could be indicated, a direct overlay of the AM and PM 2D photographs would not have confirmed the alignment of the teeth because of the difficulty in replicating the AM photographic angulation at PM.
An upper silicone impression was taken at PM. A plaster model was constructed and digitally scanned. This 3D image was then aligned appropriately (Figure 3) and compared to the AM photographs as described by Reesu et al.19
The dental practice was contacted following the PM examination and after looking through archives the practice produced further records that were 15 years old, including hand-written notes, a hand-written chart and dental radiographs. These older records were considered alongside the recent records to produce a single AM chart. The AM radiographs confirmed the presence of restorations in posterior teeth, some of which had been subsequently replaced. However, the upper anterior veneers and crown on the archived chart differed to the PM findings (Figure 4).
For case 1, the GDP's AM dental charts were deemed to contain errors, including restorations present but not charted, restorations charted but not present, tooth transposition and filling surface transposition (buccal/lingual). The GDP's AM dental photographs proved to be an important aspect of the AM dental records, and enabled the forensic odontology method of overlaying an AM photograph of teeth to an appropriately orientated 3D scan of the PM model.
A PM dental chart was compiled at the PM dental examination. Recent AM dental records had been obtained from the dental practice. The GDPs AM dental chart and PM dental chart were compatible, with one explainable difference that the fissure sealant at LR6 had been lost (Figure 5). However, because no dental restorations were present at PM, the dental records alone were not considered by the forensic odontologists to have adequate detail to facilitate identification using odontology.
An AM selfie photograph was available of the individual, obtained by the Coroners Officer. The photograph was of good quality, with a broad smile showing anterior teeth. PM photographs were taken at the PM dental examination and comparable features were noted between the AM selfie and the PM photograph (Figure 6). While similarities were indicated, a direct overlay of the AM and PM 2D photographs would not have confirmed the alignment of the teeth because of the difficulty in replicating the AM photographic angulation at PM.
An upper silicone impression was taken at PM. A plaster model was constructed and digitally scanned. This 3D image was then aligned appropriately and compared to the AM photographs (Figure 7) as described by Reesu et al.19 The 3D scan and 2D selfie photograph was compatible.
At PM, Case 3 was in mid-orthodontic treatment with fixed appliances and a missing premolar unit in each quadrant. Some tooth-coloured restorations were also present. The AM records from the dental practice were recent. The GDP's dental chart did not document any missing premolars; however, the AM restorations charted were compatible with the PM findings (Figure 8).
The AM orthodontic records contained a number of AM photographs and radiographs, and clinical notes recorded the extraction of all four first premolars and provision of fixed appliances. On this occasion, the AM radiographs were of limited use for forensic odontology purposes owing to the presence of fixed appliances at PM. Similarly, AM orthodontic photographs were taken pre-treatment and because alignment of teeth changes during orthodontic treatment, their use was limited, but they still proved to be of value. Some of the AM orthodontic photographic images recorded the presence of white patches (Figure 9a), including at the cusp tips of UL3 and UL5. At PM, white patches were present at the cusp tips of UL3 and UL5 (Figure 9b).
At PM, the dental findings for the skeletonized remains were charted (Figure 10a). The skull and mandible were separated, but did articulate with each other. The PM findings differed to the recent AM GDP chart, particularly for the maxilla (Figure 10b).
Forensic odontology relied upon the GDP's AM radiographic images for both upper posterior sextants, but not the GDP's dental chart. In the upper anterior sextant, the PM finding was that UR2 was missing and a gap present (Figure 11); however, the UR2 was charted as present on the GDP's AM chart. On further investigation, family accounts described a missing upper front tooth on the right for many years. This was corroborated with a family photograph. The quality of the family photograph was not suitable for overlay, and the photograph was used by the forensic odontology for no purpose other than to corroborate the family's account of a missing tooth.
For Case 5, at PM, two teeth were missing and no restorations were present (Figure12a). AM records had been obtained from a dental practice, which included a chart (Figure 12b). The AM and PM charts were compatible; however, the dentition lacked dental restorations.
The Coroner's Officer also sourced AM records from a business providing aligners. An AM photograph and AM static images of 3D scans were obtained. A PM photograph was compatible with the AM photograph and AM 3D scan image of the anterior teeth (Figure 13). Unfortunately, it was not possible to obtain the AM 3D files, only the static images.
At PM, upper and lower silicone impressions were taken. A plaster model was constructed and digitally scanned. The 3D PM scans were then orientated and compared to the AM 3D images (Figure 14). The AM and PM 3D scan images were compatible, both showing space between UR5 and UR7, a rotated UR7 and a buccally positioned LR5, and otherwise well aligned upper and lower arches.
In all five of the cases reported here, the forensic odontologists were assisted by having AM photographic records available. Furthermore, for three of the cases, the forensic odontologists benefited from the use of 3D imaging. The 2D–3D comparison technique was a useful and necessary adjunct to supplement the comparison of AM and PM dental charts, and facilitated a conclusion that would not have been possible using the dental charts alone.
The GDP's dental records, including dental charts, are important forensic evidence in cases of human identification. Forensic odontologists must be able to interpret the multitude of formats in which GDPs record dental charts (see differences between Figures 1b, 4a, 5, 8, 10b, 12b). Forensic odontologists may also have to try to explain charting errors. Cases 1 and 4 demonstrated inaccuracies in the GDP dental charts, and in Case 3, the GDP dental chart had not been updated to reflect extractions provided under the care of an orthodontist. Common charting errors include teeth charted, but that are actually missing, teeth missing that are charted, incorrect surfaces recorded for fillings that are present, and tooth-coloured fillings that are present, but not charted.5 The use of dental records is an important and well-established method for forensic human identification, and is sometimes overlooked by dental practitioners. The GDC expect complete and accurate dental records to be maintained for patients. Unfortunately, this is not always the case. Forensic odontologists do use all the AM records available to them; however, this does not excuse inaccurate dental charts.
As well as problems with inaccurate dental charts, the quality of AM photographic image evidence can sometimes be an issue for forensic odontologists. The quality of the original image, or the way in which the image is stored, is out of the control of the forensic odontologist. Subsequently, the quality of the images with which forensic odontologists are presented as AM evidence can vary (see Figures 2a, b, 6a, 9a, 13a, 14a), and careful consideration of the evidentiary value of an AM image is required.
AM photographs were useful in all five of the cases reported here. In the experience of the authors, AM dental photographs are seldom part of general dental practitioner records; however, most practitioners have access to a computer. In the UK, private and specialist practitioners are more likely than practitioners in mixed NHS/private practice to use clinical photography, and NHS practitioners are the least likely to use clinical photography.22 When photographs are taken and stored in patient records by GDPs, they can be very useful for forensic odontologists.
In Case 2, a personal selfie photograph was available. About 1.38 billion smartphones were sold worldwide in 2020.23 With the development of smartphone technology, these advanced hand-held devices have enabled individuals to take photographs or selfies and share them instantly on social networking sites. When personal photographs of good quality are available and show the anterior teeth while smiling, it may be possible for them to be used effectively to support an odontology conclusion.
Two of the cases, Cases 1 and 2, demonstrated the method of overlaying 2D AM photographs onto 3D scans of models of the teeth at PM. This method enabled easy comparison between AM and PM images, and has been shown to facilitate better forensic odontology conclusions than a 2D–2D comparison.19,20 When taking a 2D photograph, replicating the exact AM angle of photographic exposure is almost impossible, and therefore prohibits overlaying a 2D image with another 2D image. In practical terms, this restricts the odontologist to highlighting comparable features in the two 2D images. When a PM 3D scan is available, rotation and alignment of that 3D scan allows accurate replication of angulation, and facilitates overlaying the 2D image.
3D technology is becoming more widely used in dental practice, particularly for orthodontic and alignment purposes. As this progresses, forensic odontologists may find it necessary to use AM 3D records and photographs for human identification. The authors would not advocate the use of AM photography or 3D scans alone to establish an identity when dental charts, radiographs or clinical notes exist; however, the five cases demonstrate how AM photographs of teeth and 3D scanning can be used by forensic odontologists as an important adjunct in reaching an odontology conclusion. This restricted use as an adjunct may well change as technologies and methodologies improve further. It is conceivable that dental charting in general dental practices of the future may be replaced or supplemented with a series of intra-oral photographs and 3D scans. If this happens, forensic odontologists will have the opportunity to use highly accurate AM records of the dentition.
Errors in dental charting may be considered by clinicians to be minor, or inconsequential to the treatment of the patient while they are alive. Similarly, the quality of images and scans stored as dental records by GDPs may prove to be more important as forensic evidence at PM than as a clinical AM record. The current difficulties that forensic odontologists can encounter with human identification using odontology have been discussed, and highlight that identification using odontology should only be attempted by forensic odontologists.
Dental records, including dental charts, facilitate human identification using odontology. However, dental charting sometimes contains inaccuracies, or dentitions may not contain sufficient restorative features to enable identification. AM photographs, including selfies, dental intra-oral photographs and family photographs, can be useful for forensic odontology purposes. The method of comparing 2D intra-oral photographs and selfie photographs to 3D PM scans has been used successfully as an adjunct in human identification using odontology.
