Application of 3D imaging and selfies in forensic dental identification.

With increased access to smartphones, the selfie has gained immense popularity in the past decade. Selfie images could be a significant source of ante-mortem (AM) image data in cases where dental records are unavailable or considered insufficient. The application of 3D imaging and selfies has not been explored to its full potential in human dental identification. The present study aimed to evaluate the feasibility of using selfies as AM data and comparing with 3D post-mortem (PM) scans as an alternative to multiple 2D PM photographs in forensic dental identification. The study sample consisted of 18 selfies (12 matching and 6 non-matching) and 15 3D dental scans obtained from the study participants. The study sample was assessed by 6 experienced forensic odontologists (Raters) in two phases; Phase I-Visual comparison of 2D selfies to 3D scans and Phase II-2D selfies superimposed upon 3D scans. Each rater looked at 15 cases, and a total of 1620 comparisons were made by 6 raters (72 for the 12 matching cases and 1548 were for non-matching) and the opinions for each of the comparisons were analyzed. The results of the study show that use of the 3D superimposition method increased the certainty of the conclusions reached by the raters for the cases with correct matches. Furthermore, 94.2% of the 1548 non-matching comparisons were correctly excluded, compared with 77% for the 2D visual comparison method. The study demonstrated the applicability of this 3D method as a valuable tool in assisting the forensic odontologist with dental identification using selfies.

Forensic dental identification using two-dimensional photographs of a smile and three-dimensional dental models: A 2D-3D superimposition method.

Photographs of a person smiling may provide valuable information about their anterior dentition. These images can be an alternative ante-mortem (AM) dental source in cases with no dental records, which gives the forensic odontologist a significant opportunity for comparative dental analysis. There are no reported studies that have investigated the reliability of a superimposition technique using 2D photographs of a smile and 3D dental models in dental identification. The aim of this study was to explore novel odontological methods by combining 2D photographs with 3D dental models, simulating a dental identification scenario. The objective was to increase the accuracy of dental identification using an AM photograph with the aid of 3D imaging as an alternative to post-mortem (PM) photographs. The study comprised of 31 3D dental models (simulating PM information) and 35 digital photographs (simulating AM information). The data was analysed in two phases: Phase I- Visual Comparison of 2D-3D images and Phase II- 2D-3D superimposition after a wash out period. Both methods were analysed by the principal investigator. Further, one-third (ten) of the sample was evaluated by six raters (three experienced forensic odontologists and three forensic odontology MSc. students). The inter-rater agreement was assessed using intra-class correlation (ICC 2, 1, absolute). The results of the study suggest that the inter-rater and intra-rater reliability using 3D superimposition was highest (ICC ≈ 1.0). In summary, there was an increase in match rates and higher certainty among the opinions reached when using the 2D-3D superimposition method. The procedure attempted to reduce the limitations of previously existing 2D methods and is intended to assist forensic experts with an alternative method in dental identification when expressing conclusions on a case using photographs.

Automated Identification from Dental Data (AutoIDD): A new development in digital forensics.

There has been a significant expansion in the use of 3-dimensional (3D) dental images in recent years. In the field of forensic odontology, an automated 3D dental identification system could enhance the identification process. This study presents a novel method for automated human dental identification using 3D digital dental data by utilising a dental identification scenario. The total study sample was divided into two groups: Group A (120 dental models) and Group B (120 Intra-oral scans-IOS). Group A data was composed of 3D scanned dental models of post-orthodontic treated patients (30 maxillary and 30 mandibular). This data was considered as AM digital data. To generate an identical sample, the dental casts (60) of the same patients were retrieved and laser scanned. These models were considered as PM digital data. Group B data (IOS) was obtained from 30 study participants. To reconstruct a dental identification scenario 30 maxillary and 30 mandibular IOS were obtained from 30 participants and were considered as IOS-AM. After one year, another set of IOS (60) were acquired from the same participants and were considered as IOS-PM. The results showed that the AutoIDD (Automated Identification from Dental Data) software was consistent in accuracy; capable of differentiating "correct matches" (high match percentage) from "non-matches" (very low percentage) by 3D image superimposition. The match percentage of the maxillary and mandibular IOS ranged from 64 to 100% and 81-100 %, with a mean distance (mm) of 0.094 and 0.093 respectively. This study demonstrated the feasibility of using 3D scans through a new automated software - AutoIDD in digital forensics to assist the forensic expert in confirming the identity of a deceased individual from the available AM dental records.

Inaccurate Dental Charting in an Audit of 1128 General Dental Practice Records.

Fourteen dentists at different practices in the UK assessed the dental charts of 1128 patients who were new to the dentist but not new to the practice; 44% of the dental charts were found to be inaccurate. Inaccuracy of the individual practice-based charts ranged between 16% for the best performing practices to 83% for the worst: 5% of dental charts had too many teeth charted and 5% had too few teeth charted; 13% of charts had missed amalgam restorations and 18% had missed tooth-coloured restorations; 5% of charts had amalgam restorations recorded but with the surfaces incorrect (eg an MO restoration charted but a DO restoration actually present); 9% of charts had tooth-coloured restoration surfaces incorrectly recorded. For 7.5% of charts, amalgams were charted but not actually present. Other inaccuracies were also noted. The authors reinforce the requirements of the GDC, the advice of defence organizations, and the forensic importance of accurate dental charts. Clinical relevance: Dental charting forms part of the patient's dental records, and the GDC requires dentists to maintain complete and accurate dental records.

Epidermal growth factor contamination and concentrations of intact human chorionic gonadotropin in commercial preparations.

It is well-known that many urinary-derived human chorionic gonadotropin (hCG) preparations contain a variety of contaminating agents that may influence the efficacy and possible safety of their application. Herein, we report the finding of epidermal growth factor (EGF) contamination and high hCG beta core levels in two leading brands of hCG - findings that will promote the use of recombinant hCG instead of the cruder, urinary-derived formulations.

Homocysteine oxidation and apoptosis: a potential cause of cleft palate.

Cleft palate is the most common craniofacial anomaly. Affected individuals require extensive medical and psychosocial support. Although cleft palate has a complex and poorly understood etiology, low maternal folate is known to be a risk factor for craniofacial anomalies. Folate deficiency results in elevated homocysteine levels, which may disturb palatogenesis by several mechanisms, including oxidative stress and perturbation of matrix metabolism. We examined the effect of homocysteine-induced oxidative stress on human embryonic palatal mesenchyme (HEPM) cells and demonstrated that biologically relevant levels of homocysteine (20-100 microM) with copper (10 microM) resulted in dose-dependent apoptosis, which was prevented by addition of catalase but not superoxide dismutase. Incubation of murine palates in organ culture with homocysteine (100 micro) and CuSO(4) (10 microM) resulted in a decrease in palate fusion, which was not significant. Gelatin gel zymograms of HEPM cell-conditioned media and extracts of cultured murine palates, however, showed no change in the expression or activation of pro-matrix metalloproteinase-2 with homocysteine (20 microM-1 mM) with or without CuSO(4) (10 microM). We have demonstrated that biologically relevant levels of homocysteine in combination with copper can result in apoptosis as a result of oxidative stress; therefore, homocysteine has the potential to disrupt normal palate development.

Microarray analysis of murine palatogenesis: temporal expression of genes during normal palate development.

The mammalian face is assembled in utero in a series of complex and interdependent molecular, cell and tissue processes. The orofacial complex appears to be exquisitely sensitive to genetic and environmental influence and this explains why clefts of the lip and palate are the most common congenital anomaly in humans (one in 700 live births). In this study, microarray technology was used to identify genes that may play pivotal roles in normal murine palatogenesis. mRNA was isolated from murine embryonic palatal shelves oriented vertically (before elevation), horizontally (following elevation, before contact), and following fusion. Changes in gene expression between the three different stages were analyzed with GeneChip microarrays. A number of genes were upregulated or downregulated, and large changes were seen in the expression of loricrin, glutamate decarboxylase, gamma-amino butyric acid type A receptor beta3 subunit, frizzled, Wnt-5a, metallothionein, annexin VIII, LIM proteins, Sox1, plakophilin1, cathepsin K and creatine kinase. In this paper, the changes in genetic profile of the developing murine palate are presented, and the possible role individual genes/proteins may play during normal palate development are discussed. Candidate genes with a putative role in cleft palate are also highlighted.