Intraoral Scanners in Personal Identification of Corpses: Usefulness and Reliability of 3D Technologies in Modern Forensic Dentistry

Orofacial assessment as digital path for forensic and legal evidence record

In forensic scenarios, such as armed conflicts or mass disasters, the oral cavity can be a valuable source of identification information relevant to legal issues. In many European Union countries, it is mandatory to register dental records for identification purposes. A pilot and quasi-experimental study was performed. The study aims to analyze two methodologies, photography and wireless intraoral (IO) laser scanner, in the scope of the orofacial record in forensic pathology, highlighting their impact on human identification. The IO scanner i700 (Medit, Lusobionic, Portugal) and Canon 5D-Full Frame equipment were used to record the individual status, living patients (n = 5), and forensic cases (n = 5). IO and extraoral anatomical structures were recorded following six parameters: time, mineralized and soft detail, communication, extra devices, and distortion. The statistical analysis was performed in accordance with a scoring system and Mann-Whitney (P < 0.05) analysis. The photography method recorded extraoral data for all samples (score range between 15 and 23). The time elapsed to complete an IO scan in forensic cases was shorter than with photography, without requiring additional sources of light or mirror devices. Living patients and corpses identified statistically significant differences. It can be concluded that laser scanners are a valuable tool in the field of forensic pathology and can be used to record and analyze anatomic-morphological data for identification purposes accurately.

Key points

Human identification engages in orofacial details records.Photographic and laser scans record intraoral and extraoral anatomic structures.Forensic cases assessed by intraoral scanner technology are accurate and less time-consuming, optimizing the orofacial data for identification.

Digital intraoral and radiologic records in forensic identification: Match with disruptive technology

While clinical dentistry has seamlessly integrated the digital revolution, there is a gap in the technological capabilities of forensic dentistry.The study aimed to compare the superimposition accuracy of two different three-dimensional record formats, namely the intraoral scanner and cone beam computer tomography, in the context of forensic identification.The sample consisted of randomly selected adults (n=10) of both sexes aged between 20 and 50 years. Following the acquisition of data using the Medit i700 wireless scanner and the iCAT Tomograph with InVivo software, the records were analysed and compared through superimposition using Medit Scan Clinic software to assess the technical precision of anatomical identification details.The results obtained through the superimposition of dental and bone records following intra- and inter-observer analysis enabled an accurate comparison and identification of an individual. This method can differentiate between positive and negative matches, achieving exclusion results and offering a potential solution to overcoming the absence of a standardisation procedure in human identification.

New Perspectives in Third Molar Auto-Transplantation: Literature Review and a Case Report of Clinical, Financial and Forensic Implications

Third molar extraction is the most common procedure in oral and maxillofacial surgery. Third molars are considered less functional than other teeth and are often extracted. Sometimes, they are also used for auto-transplantation for the benefit of oral rehabilitation. Since many biological factors are involved in this surgical approach, herein, we outline a review of the biological characteristics of medico-legal/forensic interest, in addition to presenting a successful clinical case. A scoping review of currently available research data (following the principles of PRISMA-ScR or the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) on third molar auto-transplantation was conducted by drawing upon the main databases (Scopus, PubMed, Google Scholar and LILACS) to evaluate biological and clinical characteristics possibly relatable to forensic issues. All the collected data were summarized and elaborated on for the purpose of this article. A patient underwent extraction of the right upper first molar and auto-transplantation of the unerupted ipsilateral third molar. Many biologic and clinical factors are involved in the success of this clinical procedure. Knowledge of third molar anatomy, of its development and viable surgical approaches are all essential elements; just as important are the treatment of the tooth before and after transplantation and the integrity of the periodontal ligament. Follow-up of the clinical case for 5 years made it possible to verify the stability of the procedure over time. Third molar auto-transplantation is feasible and cost-effective. However, the use of third molars as donor teeth in auto-transplantation may have medico-legal implications. The lack of official protocols and consistent evidence-based guidelines for operators still prevent such a procedure from becoming mainstream; therefore, it is viewed with suspicion by clinicians and patients, even though the biological factors herein detected point to a reasonably high degree of safety. The understanding of many specific biological and clinical factors involved in the stability of third molar auto-transplantation allows for a thorough understanding of the forensic implications relevant to clinical practice. Effective communication and information provision are therefore of utmost importance, in the interest of both patients and doctors.

3D intraoral scan and diagnostic plaster model under General Data Protection Regulation - Legal protection

No legal subsumption of dental impressions, plaster models and intraoral scanning has been attempted yet. It should be examined to what extent the General Data Protection Regulation (GDPR) applies to them. The aim of this study is to legally classify 3D intraoral scans and plaster models prepared on the basis of alginate impressions within the context of personal data safety and determination of legal protection applicable to their use. The authors set the deliberations concerning legal protection of plaster models and 3D intraoral scans in the light of recently published articles regarding palatal rugae pattern stability, thus enabling accurate personal identification regardless of age or dental treatment. The deliberations concerning legal protection will be based on the analysis of the international legal acts, in particular GDPR. The intraoral scan constitutes biometric data, because it is information about a natural person - a patient is identifiable on the basis of elements defining physical identity. The plaster model itself does not constitute personal data. However, both of them constitutes medical documentation. The biometric data must be processed in a manner compliant with the GDPR provisions. The GDPR shapes only aims which should be attained. When creating a data safety system, ISO or NIST standards may help to ensure the proper level of protection against possible liability resulting from breaches in the scope of personal data processing.

Evaluation of the stability of the palatal rugae using the three-dimensional superimposition technique following orthodontic treatment

OBJECTIVES

To determine the uniqueness and stability of the palatal rugae after orthodontic treatment.

METHODS

Cast models of untreated subjects (n=50) were obtained twice at intervals of 8-30 months. Cast models of patients who received non-extraction (n=50) and extraction (n=50) orthodontic treatment were obtained before and after treatment at intervals of 11-41 months and 14-49 months, respectively. All 300 cast models were scanned digitally. The palatal rugae were manually extracted and transformed into 3D point clouds using reverse engineering software. An iterative closest point (ICP) registration algorithm based on correntropy was applied, and the minimum point-to-point root mean square (RMS) distances were calculated to analyze the deviation of palatal rugae for scans of the same subject (intrasubject deviation [ISD]) and between different subjects (between-subject deviation [BSD]). Differences in ISD between each group and the deviation between ISD and BSD of all 150 subjects were evaluated.

RESULTS

Significant differences were found in the 150 ISD and 1225 BSD in each group, as well as the 150 ISD and 11175 BSD across all groups. The mean values of ISD in untreated, non-extraction and extraction group were 0.178, 0.229 and 0.333 mm, respectively. When the first ruga was excluded in the extraction group, the mean ISD decreased to 0.241 mm, which was not significantly different from that in the non-extraction group (p=0.314).

CONCLUSIONS

Orthodontic treatment can influence the palatal rugae, especially in cases of extraction. Furthermore, variation mainly existed in the first ruga in cases of extraction. However, palatal rugae are still unique and may be used as a supplementary tool for individual identification.

CLINICAL SIGNIFICANCE

This study indicates that palatal rugae might be applied in the evaluation of orthodontic tooth movement and forensic individual identification. The registration algorithm based on correntropy provides a credible, precise, and convenient method for palatal rugae superimposition.

Clear Aligners: Between Evolution and Efficiency-A Scoping Review

In recent years, clear aligners have diversified and evolved in their primary characteristics (material, gingival margin design, attachments, divots, auxiliaries), increasing their indications and efficiency. We overviewed the brands of aligners used in Italy and reviewed the literature on the evolution of clear aligners based on their characteristics mentioned above by consulting the main scientific databases (PubMed, Scopus, Lilacs, Google Scholar, Cochrane Library). Inclusion and exclusion criteria were established. The data were collected on a purpose-made data collection form and analyzed descriptively. From the initial 580 records, 527 were excluded because they were not related to the subject of the review or because they did not meet the eligibility criteria. The remaining 31 studies were deemed comprehensive for the purpose of the review, although the “gingival margin design” feature and “auxiliaries” tool are not well represented in the more recent literature. Current knowledge on invisible aligners allows us to have a much clearer idea of the basic characteristics of aligner systems. There remains a need to deepen the use of systems other than Invisalign™ to give greater evidence to aligners that are very different based on the characteristics analyzed here and that are very widespread on the market.