Role of forensic odontologist in post mortem person identification

Retrospective evaluation of the morphometric properties of intact maxillary sinus using cone-beam computed tomography for sex estimation in an Indian population

Background

Sex estimation is crucial to forensic examinations. In order to estimate sex, intact bones are used if the majority of bones are severely deformed and recovered in fragments. This study aims to analyze sexual dimorphism in intact maxillary sinuses using CBCT scanning to evaluate morphometric properties for sex identification.

Methods

A total of 318 subjects, consisting of 159 males and 159 females, aged between 20 and 60 years without sinus pathology were included in this diagnostic, retrospective cross-sectional study. Bilateral measurements of the volume, height, width, and length of the maxillary sinuses were obtained and compared to evaluate the differences between sexes. Subsequently, a descriptive analysis using mean and standard deviation was performed, followed by a comparison between sexes with a p-value being less than 0.05 and Student's t-test. Finally, a discriminant analysis was performed separately for the right and left maxillary sinuses.

Results

Males and females showed statistically significant variations in the length, width, and volume of the maxillary sinuses. Specifically, on the right side, males had longer maxillary sinuses than females (t = 5.6203, p < 0.0001). Meanwhile, on the left side, females had wider maxillary sinuses than males (t = 8.621, plt0.0001). In addition, males had greater volumes of maxillary sinuses on the right (t = 6.373, p < 0.0001) and left (t = 3.091, p < 0.0001) sides than females. The results of the discriminant analysis showed that the left width parameter had the highest accuracy of sex estimation (74.21%), followed by the Right Length (70.07%) and left volume (66.66%) parameters. The left height parameter had the lowest accuracy of sex estimation (49.37%).

Conclusion

In forensic odontology, the volume of maxillary sinus can serve as a valid radiographic indicator of sex estimation.

The role of dentistry in forensic medicine: the process of human remains identification

The use of dentistry in forensic medicine has gradually become an indispensable tool in the process of identifying human remains. In recent years, there has been a significant increase in the importance of this field in the identification of victims in mass disasters, criminal investigations, ethnic research, and the identification of decomposed and distorted bodies, such as drowning, fire and car accident victims. Dental examinations allow for precise determination of individual identities based on unique dental features. Various methods applied in forensic medicine in the realm of dentistry include dental impressions, radiographs, photographic examinations, rugoscopy, cheiloscopy, and molecular methods. Advanced dental analysis techniques make it possible to restore identities even in the most challenging cases. Equally important is the integration of knowledge and methods of forensic dentistry with other forensic disciplines such as molecular genetics and anthropology. Further research and development in this branch of science are crucial for improving investigative processes and ensuring the dignity of mass disaster victims. The aim of this work is to present methods using teeth for the identification of human remains along with the latest advancements in forensic DNA technology, which utilizes dental evidence to aid in the identification of human remains.

Identification issues in bodies maimed by train fatalities: The role of the forensic pathologist

Traffic accident injuries are relevant causes of mortality in industrialized countries. Among traffic accidents, the most destructive effect on the victim's body is produced by trains, which in a very short time provoke a complete distortion of the normal anatomical profiles and extensive amputations of the body. Deaths by severe body mutilation and/or decapitation require complex forensic investigation, as the victims' identification and the recognition of their body are not often feasible. In this study, a retrospective analysis of a series of cases of railway accidents is presented, with the aim of showing potential identification strategies, including a systematic physical re-assembling of the body. Among the railway fatalities assessed at the University Institute of Legal Medicine of Milan from 2016 until 2020, 61 cases were analyzed, focusing on the collection of postmortem data to improve accuracy for the identification of the victims. The results showed that the identification could be based on elements traditionally called "secondary identifiers" which, however, are becoming more and more important for positive identification, especially when dealing with migrants, vagrants, and homeless people. However, several issues need to be considered such as the limitations of the public prosecutors to perform expensive analyses (i.e., genetic testing), and the lack of antemortem data to be compared with postmortem findings, both odontological and fingerprint. In cases where it is not possible to proceed with identification or formal recognition of victims of railroad accidents with severe mutilations, a systematic physical re-assembling of the body is critical to reaching positive identification.

Identification method for dental alloy type using a cosine similarity program: A preliminary investigation

Although dental evidence is frequently used for the identification of unidentified persons, information about the many types of alloys used in prosthetics is not utilized. If the type of alloy can be identified from a small amount of material, the scope of the search could be narrowed. In this experiment, a method was investigated for identifying the alloy type using 3 kinds of cutting points (a white point and 2 types of silicone points). Wavelength-dispersive X-ray spectroscopy (WDS) was used for elemental analysis. The elements were translated into multidimensional vectors, and the cosine similarity was calculated to compare vectors of the WDS results and vectors of the official data of alloys. According to the results, cosine similarity showed a concordance of more than 0.8. The developed program is expected to be useful as a method for identifying alloy types using only a small amount of grinding dust.

Application of Forensic DNA Phenotyping for Prediction of Eye, Hair and Skin Colour in Highly Decomposed Bodies

In the last few years, predicting externally visible characteristics (EVCs) by adopting informative DNA molecular markers has become a method in forensic genetics that has increased its value, giving rise to an interesting field called "Forensic DNA Phenotyping" (FDP). The most meaningful forensic applications of EVCs prediction are those in which, having only a DNA sample isolated from highly decomposed remains, it is essential to reconstruct the physical appearance of a person. Through this approach, we set out to evaluate 20 skeletal remains of Italian provenance in order to associate them with as many cases of missing persons as possible. To achieve the intended goal, in this work we applied the HIrisPlex-S multiplex system through the conventional short tandem repeats (STR) method to confirm the expected identity of subjects by evaluating phenotypic features. To investigate the reliability and accuracy of the DNA-based EVCs prediction, pictures of the cases were compared as they were available to researchers. Results showed an overall prediction accuracy greater than 90% for all three phenotypic features-iris, hair, and skin colour-at a probability threshold of 0.7. The experimental analysis showed inconclusive results in only two cases; this is probably due to the characteristics of subjects who had an intermediate eye and hair colour, for which the DNA-based system needs to improve the prediction accuracy.

Palatal Rugae Patterns in Fars, Turkmen, and Sistani Ethnicities in the Eastern Part of the Caspian Littoral of Iran

In forensic medicine, it is important to identify whole or fragmented bodies. This aim can be particularly challenging in mass disasters. Palatal rugae patterns can be used as a surrogate parameter in forensic medicine. This stems from the difficulty in falsifying these patterns, their resistance to trauma, to decomposition for several days postmortem, and to combustion under high-temperatures, as well as being distinguishable among different races. The present study aimed to analyze the differences in the palatal rugae patterns among three Iranian ethnicities (Fars, Turkmen, and Sistani). This retrospective study involved the use of archived materials. The study casts were selected from the database of patients who visited a private orthodontics clinic. A total of 309 dental casts (103 Fars, 103 Turkmen, and 103 Sistani) were assessed, which belonged to 181 females and 128 males aged between 12 and 30 years (mean: 16.86 ± 3.18 years). The difference in the mean number of palatal rugae in women between the three ethnicities was statistically significant. Also, the differences in the total number of straight rugae were significant between the three ethnic groups. The most common rugae shapes in the three ethnic groups were the straight and wavy shapes. The length of the palatal rugae in the primary and secondary rugae among the study subjects younger than 18-years-old was significantly different between the three ethnic groups. Thus, the present research highlighted the differences in palatal rugae patterns among three Iranian ethnicities. Therefore, palatal rugae can be used in forensic medicine as a complementary approach to human identification.

Knowledge and awareness of forensic dentistry course among undergraduates

Forensic odontology is an expanding field within the domain of forensic sciences, where dental knowledge is applied in identification of individuals through analysis of the dental-related records. The study goal was to determine if undergraduate students were aware of the forensic dentistry course. A cross-sectional survey was initiated about the need for forensic courses in UG program. Nearly 100 students participated in this survey, data have been collected, and graph has been plotted. Data have been collected with the help of SPSS software; data have been analyzed and plotted as graph. One hundred students responded the survey; only limited people's opinions have been collected. The result varies among the students; 58% knows about the importance of forensic odontology in dentistry using Chi-square value, P = 0.09. The majority of students, who replied to this poll, had some understanding and awareness of forensic odontology in dentistry, but they need to learn more about how it is practiced.

Efficacy of a novel bone preprocessing method for better DNA yield

In cases involving identification of missing persons, mass disasters and ancient DNA investigations, bone and teeth samples are often the only, and almost always the best, biological material available for DNA profiling. Standard methods for extraction of DNA from such samples involve grinding of the bone and teeth samples. Here, we present an extremely efficient protocol for recovery of DNA from bone samples by a method of scrapping. The study was carried out on 25 samples and it was found that the quantity of DNA isolated by the scrapping method was up to 1.131 ng/µl with a success rate of 93% as compared to a much lower yield of 0.359 ng/µl DNA isolated with a success rate of 28% through the grinding method. The scrapping method of DNA extraction has been proven to be extremely useful in forensic examination of challenging samples that had multiple failures using the traditional grinding method.

Effects of high temperature on dental restorative materials for forensic purposes

This study aimed to observe the effects of high temperature on different restorative dental materials by detecting changes in their microstructural and elemental composition. Disk shaped samples (10 mm diameter, 2 mm depth) were prepared from 8 dental materials (compomer, glass carbomer, ormocer, giomer, zinc reinforced glass ionomer (GI), silver-alloy reinforced GI, zirconia reinforced GI, and conventional GI). Scanning electron microscopy/Energy dispersive X-ray spectroscopy (SEM/EDS) was used to characterize sample surface structures and elemental composition. The same samples were also analyzed using X-ray fluorescence (XRF) to determine the trace element content. Each sample was placed in a porcelain furnace and exposed to 900 °C for 30 min. Observations of macroscopic changes in samples after exposure high temperature were recorded. The microstructural changes in sample surfaces after incineration were detected by SEM. The elemental compositions obtained before and after the incineration were compared after repeating the XRF and EDS analyses. Dental materials demonstrated specific macroscopic changes and microstructural deteriorations detected by SEM images after exposure to high temperature. While several changes occurred in the elemental content of materials in terms of amount, the original elemental composition was preserved. The ability to distinguish dental materials by elemental analyses has had an important impact on the identification process.

Three-dimensional superimposition of digital models for individual identification

Dentition is an individualizing structure in humans that may be potentially utilized in individual identification. However, research on the use of three-dimensional (3D) digital models for personal identification is rare. This study aimed to develop a method for individual identification based on a 3D image registration algorithm and assess its feasibility in practice. Twenty-eight college students were recruited; for each subject, a dental cast and an intraoral scan were taken at different time points, and digital models were acquired. The digital models of the dental casts and intraoral scans were assumed as antemortem and postmortem dentition, respectively. Additional 72 dental casts were extracted from a hospital database as a suspect pool together with 28 antemortem models. The dentition images of all of the models were extracted. Correntropy was introduced into the traditional iterative closest point algorithm to compare each postmortem 3D dentition with 3D dentitions in the suspect pool. Point-to-point root mean square (RMS) distances were calculated, and then 28 matches and 2772 mismatches were obtained. Statistical analysis was performed using the Mann-Whitney U test, which showed significant differences in RMS between matches (0.18±0.03mm) and mismatches (1.04±0.67mm) (P<0.05). All of the RMS values of the matched models were below 0.27mm. The percentage of accurate identification reached 100% in the present study. These results indicate that this method for individual identification based on 3D superimposition of digital models is effective in personal identification.

A novel identification method using perceptual degree of concordance of occlusal surfaces calculated by a Python program

One of the important issues during the response to a mass disaster is the identification of victims. In this study, we verified the use of the occlusal morphology of molars for individual identification. The aim of this study was to establish a simple new method for identifying individuals from molar data. Using Python, we developed programming that included the perceptual Hash (pHash) function and the Hamming distance (HD) between antemortem data (AMD) and postmortem data (PMD). The AMD comprised 2,215 dental models. The PMD were selected from the AMD set and comprised 17 models from the same individual with changes over time. As a result, 16 PMD models (over 90%) were ranked in the top 5%. Although identification using only a single molar is difficult, there is the possibility of narrowing down victims' identity with high accuracy through verification using multiple teeth. This system is expected to be useful as a very simple method of identification.

Determining the effective number and surfaces of teeth for forensic dental identification through the 3D point cloud data analysis

Background

The assimilation between three-dimensional (3D) imaging techniques and dental forensic science can provide rich and stable information for human identification. This study aimed to determine the effective number and surfaces of teeth for dental identification through the 3D imaging approach.

Material and methods

In the present study, maxillary dental casts were fabricated from subjects who met the inclusion criteria and scanned using a 3D scanner Vivid 910. Rapidform XOS/SCAN software was used to create and trim the 3D point cloud data. Subsequently, two types of 3D surface data of dental casts were registered and the root mean square errors (RMSEs) between subjects were calculated using iterative closest point (ICP) algorithm in MATLAB. Two sets of experiments with 120 combinations of the superimposed 3D dataset were designed, termed as experiments 1 and 2.

Results

In experiment 1, the difference between subjects was clearly distinguished with a minimum of six teeth of the dental arch. The results of experiment 2 suggest that the labial surfaces of the anterior teeth are sufficient to be used for dental identification.

Conclusion

Through these experiments for all possible pairs of subjects, a clear difference was observed in the RMSE between the genuine and imposter pairs. These results indicate the potential of using the 3D imaging technique to achieve highly accurate human identification. It is suggested that a future study with a larger sample number will evaluate the robustness and accuracy of this method.

Forensic study of mechanical properties of dental restoration after burial in mangrove environment

Conducting research in the field of forensic sciences with methodologies that simulate situations found in the day-to-day practice of a given field of expertise is relevant insofar as this approach can produce results that are as close as possible to reality. In this context, the present study provided situations based on burial in a mangrove environment to estimate the changes in the mechanical properties (Knoop microhardness, roughness and color) of dental restorations utilizing silver amalgam, composite resin and glass ionomer cement over the time of burial. The silver amalgam showed a significant increase in surface roughness and a reduction in Knoop microhardness. Composite resin showed a statistically significant increase in color variation, and the glass ionomer cement showed significant increases in color variation and Knoop microhardness. These results allowed us to conclude that teeth restored with silver amalgam, composite resin and glass ionomer cement submitted to burial in mangrove environments produce different changes in surface roughness, Knoop microhardness and color properties depending on the time of burial to which the victims were submitted. These proprieties could help the forensic sciences to estimate time intervals for burial in mangrove environments.

Optimization of DNA extraction from dental remains

Efficient DNA extraction procedures is a critical step involved in the process of successful DNA analysis of such samples. Various protocols have been devised for the genomic DNA extraction from human tissues and forensic stains, such as dental tissue that is the skeletal part that better preserves DNA over time. However DNA recovery is low and protocols require labor‐intensive and time‐consuming step prior to isolating genetic material. Herein, we describe an extremely fast procedure of DNA extraction from teeth compared to classical method. Sixteen teeth of 100‐year‐old human remains were divided into two groups of 8 teeth and we compared DNA yield, in term of quantity and quality, starting from two different sample preparation steps. Specifically, teeth of group 1 were treated with a classic technique based on several steps of pulverization and decalcification, while teeth of group 2 were processed following a new procedure to withdraw dental pulp. In the next phase, the samples of both group underwent the same procedure of extraction, quantification and DNA profile analysis. Our findings provide an alternative protocol to obtain a higher amount of good quality DNA in a fast time procedure, helpful for forensic and anthropological studies.

Forensic odontology as a humanitarian tool

Humanitarian forensic action is the application of skills of forensic science in a conflicts or disasters as a humanitarian action. Forensic odontologist promote forensic odontology and forensic science principles to caseworks with the purpose of preventing human right violation by human identification, age estimation and where ever dental evidence is involved. Forensic odontologist is involved in all phases of disaster victim identification. According to Disaster Victim Identification Guide, if a positive match is found using dental identification it can be trusted as a standalone identifier. Dental structures are well protected and the hardest structure of the body. They resist decomposition and high temperatures and are the last one to disintegrate after death. Dental hard tissue provide abundant information in disaster victim identification, missing and unidentified persons, child abuse and neglect, domestic violence and sexual abuse with bite mark evidence, age estimation of unaccompanied minors, border control and human trafficking. The present article highlights the role of forensic odontologist in human identification for the purpose of preventing human rights violation.

Preliminary Research: Description of Lip Print Patterns in Children and Their Parents among Deutero-Malay Population in Indonesia

INTRODUCTION

Human identification is vital not only in legal medicine but also in criminal inquiries and identification. Cheiloscopy is the study of lip prints which are unique, individual, and heritable that is used for personal identification purposes in forensic odontology.

OBJECTIVE

The aim of this study is to identify the possibility of the child to inherit the lip print patterns from their parents and also to describe the lip print patterns in children and their parents among the Deutero-Malay population.

METHOD

The descriptive research used lip samples of 90 individuals including father, mother, and a child who are biologically related and their age ranges from 12 to 60 years old. The samples chosen are from the Deutero-Malay ethnic in Indonesia at least for the past two generation who obeys all the exclusion criteria of this research. Purposive nonrandom sampling method was used to collect samples by photography technique using a digital camera, and the data obtained were then analysed using Adobe Photoshop CS3 software. Grooves and wrinkles of primary quadrants one, three, six, and seven of lips were studied according to Suzuki and Tsuchihashi's classification in 1971.

RESULT

In the present study, it is found that Type I' (30.28%) is the most dominant lip print pattern and Type I (1.39%) is the least dominant among the Deutero-Malay population. Besides, this study has shown that the similarity of lip print pattern between mother and the child (57.89%) is greater compared to the father and the child (42.22%).

CONCLUSION

Based on this, we can conclude that lip print can be inherited and dissimilar for every population of race; likewise, the Deutero-Malay population has the Type I' as the most dominant lip print pattern.

Age estimation by cemental annulation rings

Context:

Tooth plays a pivotal role in the identification of a person when all other remains are ruined by natural or unnatural causes. Dental evidence can contribute to age estimation in forensic dentistry. Estimating the age of an individual with the help of a tooth for identification proves beneficial. Alternating light and dark bands seen on the cementum have been shown to be proportionate to the age of the patient in number. This was done to evaluate the cementum annulation in age determination.

Aims:

This study aimed to determine the age of an individual using tooth cementum annulation.

Materials and Methods:

In this study, twenty extracted teeth were collected and all the clinical details of the patient such as age, sex, and chief complaint were recorded. The collected teeth was preserved in formalin overnight and then washed under tap water before they were sectioned. The area selected for counting was observed under 10 × objective of light microscope, and photomicrographs were taken for the counting of the lines. At the time of analysis, the age of the patient was not disclosed to the observer.

Statistical Analysis Used:

Student's t-test was used for statistical analysis.

Results:

This study showed the correlation between the actual age of the individual and the estimated age using tooth cementum annulation method and showed significant statistical value.

Conclusion:

Incremental lines found in cementum can be used for age estimation in forensic dentistry.

Picrosirius Red and Polarization Microscopy - A Tool for Gender Differentiation

INTRODUCTION

Forensic dentistry is a branch of dentistry which in collaboration with legal profession serves an important role to maintain justice system of a country. Forensic dentists play a major role in identification of an individual. Within the literature various methods have been found to be useful in gender differentiation. An attempt was made for differentiation of gender using picrosirius red and polarization microscopy.

AIM

To evaluate picrosirius red and polarization microscopy as a tool for gender differentiation by observing birefringence pattern and distribution of thick and thin collagen fibers in males and females.

MATERIALS AND METHODS

Labial mucosal tissue obtained from 30 deceased individuals (18 male and 12 female) during autopsy was fixed in 10% formalin at 12^th hour. Tissue was processed, sectioned and stained using picrosirius red stain and the birefringence pattern of collagen fibers were studied with polarization microscope. The results were statistically analyzed using Z-test and one-way ANOVA to draw the significance.

RESULTS

The proportion of thick and thin fibres among males and females were compared. It was found that there was statistically significant difference in proportion of thick and thin fibers between male and female. Thick fibres in males were (78.13%) more than females (65.74%) and thin fibres were more in females (34.24%) than males (21.32%).

CONCLUSION

Picrosirius red and polarization microscopy may be used as a tool for gender differentiation. Yet the manner of death has to be considered during gender differentiation using this method, as in the present study out of 30 cases studied three cases of death due to debilitating diseases and poison consumption showed altered collagen distribution.

Gender determination by radiographic analysis of mental foramen in the Maharashtra population of India

Context:

Identification of gender is of primary importance in forensic investigations when only fragment of skull remains. Mandible is a hard bone and exhibits a high degree of sexual dimorphism. Gender differences were observed in the height of mandible, gonial angle, bigonial breadth, bicondylar breadth, and position of mental foramen (MF).

Aims of the Study:

The purpose of this study is to evaluate gender differences in distances from superior border of MF (SMF) and inferior border of MF (IMF) to the lower border of mandible (LBM) and height of mandible in the Maharashtra population.

Materials and Methods:

A total of 400 patients (200 males and 200 females) were considered for the study. The panoramic radiographs of patients were captured using Xtropan 2000 system and Carestream (T-Mat GIRA) films. The distance from SMF and IMF to the LBM and the height of mandible was measured.

Statistical Analysis Used:

Unpaired t-test was applied to calculate the differences between the genders.

Results:

The distance from SMF and IMF to LBM and height of mandible was more in males when compared to females, which was statistically significant.

Conclusion:

The distances from SMF and IMF to the LBM and height of the mandible showed sexual dimorphism in the Maharashtra population of India.

Oral autopsy: A simple, faster procedure for total visualization of oral cavity

Identification of humans, especially in mass disaster is a challenging aspect for team members of the disaster victim identification (DVI) unit. Identification is necessary for humanitarian and emotional reasons and for many legal issues, particularly for family members. In the modern day, all possible methods have been applied for establishing the identification of deceased individuals. The DVI team comprises specialists from different disciplines. The forensic dentist plays a major role in the identification of victims in disaster. To establish a simple, faster and time saving procedure for Postmortem dental identification in mass disaster. In this article, we present a simpler and faster method, which helps in gaining access into the oral cavity that helps in the recording of postmortem oral findings where required.

Knowledge and awareness of forensic odontology among dentists in India: A systematic review

Forensic dentistry involves the processing, review, evaluation, and presentation of dental evidence with the purpose of contributing scientific and objective data to legal processes. The present, systematic review was conducted to assess knowledge and awareness of forensic odontology among dentists in India. A systematic review of relevant cross-sectional studies was conducted regarding the level of knowledge, awareness, and practical application of forensic odontology among dentists in India. Four out of 129 studies were finally included in the present review after conducting a search of both electronic and manual scientific databases. Potential biases were addressed and the relevant data were extracted by the concerned investigators. Almost all the subjects were familiar with the subject of forensic odontology in one of the study reports. Only 12% of dentists were maintaining complete dental records in the findings of another study. Only 4% of dentists reported to have contributed to the identification of victims in a mass disaster in yet another study. The findings of another study revealed that 40% of dental practitioners did not have the expertise to identify child abuse. The results of the present review showed that the knowledge and awareness level of subjects was inadequate and that there is considerable variation in the practice of forensic odontology among dentists. It is necessary to expose dentists to the basic principles and techniques of the subject.

Cementum as an age determinant: A forensic view

CONTEXT

Forensic age estimation (FAE) defines an expertise in forensic medicine, which aims to define in the most accurate way to determine the unknown chronological age of the person involved in judicial or legal proceedings. Dental cementum is a vital tissue which demonstrates continuous apposition throughout the life of the tooth. This appositional changes of cementum helps in approximation of age inforensic investigations.

AIMS

To correlate age by measuring the overlap or coronal migration of thecementum at thecementoenamel junction (CEJ) and the thickness of the cementum at the apical third of the root.

SETTINGS AND DESIGN

A hundred freshly extracted teethfrom patients ranging from ages 17-55were longitudinal buccolingually ground sectioned using a mounted lathe wheel and Arkansas stone.

MATERIALS AND METHODS

100 freshly extracted teeth of age group ranging from 17-55 years were taken. These teeth were longitudinally ground sectioned to a thickness of 8-10μm using a mounted lathe wheel and Arkansas stone. Afterwards the teeth were examined under a light microscope using a micrometer eyepiece for measuring the overlap or coronal migration of the cementum at the CEJ and the thickness of the cementum at the apical one-third of root.

STATISTICAL ANALYSIS

Measurements of the overlap or the coronal migration of the cementum at the CEJ and the thickness of the cementum at the apical one-third of the root are correlated with age.

RESULTS

Results of the study indicated that the cementum at the CEJ migrated coronally during theaging process in case of the impacted teeth. There is also a significant increase in the thickness of the cementum at the apical onethird of rootin the case of both the impacted and erupted teeth.

CONCLUSION

Approximation of age by measuring overlap or coronal migration of the cementum at the CEJ and the thickness of the cementum at the apical one-third of the rootsets new alleys in FAE.

Forensic odontological observations in the victims of DANA air crash

INTRODUCTION

Forensic odontology or forensic dentistry is that aspect of forensic science that uses the application of dental science for the identification of unknown human remains and bite marks. Deaths resulting from mass disasters such as plane crash or fire incidence have always been given mass burial in Nigeria. This was obviously due to the fact that Forensic Pathologists whose roles involve disaster victim identification were not available at that time. However, in the DANA air crash in Lagos in 2012, the Forensic pathologist and dental teams were invited for the first time to identify the victims. The objectives of this paper are to identify the extent of victims' identification using Forensic odontology alone and its combination with DNA analysis. It also presents the pattern of fractures seen in the mandible and maxilla of the victims.

METHODS

The bodies were dissected using following the standard protocol dissection. Prior to this all the victims had Dental Radiological Examination. The oral cavities were exposed after which the Odontology team was invited for photographing first, followed by dental charting. Fractures of the mandible, maxilla including the anatomical regions were all recorded and photographed. Dental prosthesis, restorations, crowns and bridge and other findings were also noted, recorded and compared with ante mortem records where available.

RESULTS

A total of 152 bodies were recovered from the crash site while 148 victims were eventually identified through a combination of DNA analysis and forensic odontology. This represented 97.4%. Forensic odontology was the primary identifier in 10%. There were no fingerprinting information in this country at present therefore, it could not be used. A total of 89 (60%) were males while females accounted for 59(40%). This gives a ratio of 1.5:1. Most of the victims were in the age group 30-49 years; this represented 52% of the victims while the least involved age groups were victims above 60 years of age which accounted for only 4.7%. Mandibular fractures were seen in 29 victims, maxilla in 15, combined mandibullo/maxillary in 15 victims, while 89 victims had no jaw fracture. The most common area of fracture in the mandible was the body which accounted for 36.4%, closely followed by parasymphyseal region 31.9%, symphyseal 22.7% and the angle 9.0%. The most common fracture in the maxillae was palatal split fracture which accounted for 52%, this was followed by pterygoid 24%, alveolar 8% and multiple locations 16%.

CONCLUSION

A combination of DNA analysis and forensic odontology was able to identify a total of 148 victims out of 152 representing 97.4%. Forensic odontology was the primary identifier in only 10%. In the latter, poor and lack of dental records were responsible for this very low figure. The most common area of fracture in the mandible was the body which accounted for 36.4%, while that of the maxillae was palatal fracture which accounted for 52%. Padding of the back of the seats in the aircraft should be canvassed for to provide Cushing effect for passengers.