A utilização de imagens na identificação humana em odontologia legal

Forensic exploration of endodontic cements: Unveiling macroscopic and radiographic changes under high temperatures

OBJECTIVE

To evaluate macroscopically and radiographically the behavior of four endodontic sealers submitted to high temperatures, with forensic purposes.

METHODS

Sixty-four lower anterior teeth were included. All teeth were endodontically treated, and simulation of external cervical resorption (ECR) was performed. Half of the sample was filled with AH-Plus™ cement and had ECR sealed with Bio-C-Repair™. The other 32 teeth were filled with Bio-C-Sealer™ cement and had their respective ECR sealed with MTA-Repair™. Then, all teeth were introduced into a bovine bone block to simulate the alveolar bone. The teeth were submitted to incineration at temperatures of 600, 800, 1000, and 1140 °C. All teeth were radiographed before and after incineration. The pre-and post-incineration radiopacity of cements and dentin were evaluated using the ImageJ™ software and compared using a t-test for paired samples.

RESULTS

It was possible to confirm color change and appearance of cracks in the tissues and dental materials tested, varying according to the temperature. Radiographically, it was observed that the dental crowns completely detached at 1000 ° and 1140 °C, and, only at 1140 °C, the roots showed cracks. Regarding the radiopacity, there was a significant difference in the shades of gray in AH-Plus™ when subjected to 1000 ° and 1140 °C, and at 600 ° and 1000 °C in Bio-C-Sealer™. In Bio-C-Repair™ and MTA-Repair™, a difference was observed at 600 ° and 1140 °C.

CONCLUSIONS

There were macroscopic and radiographic alterations of the materials. This data is important in Forensic Dentistry and may contribute to identifying carbonized victims.

Cone-Beam Computed Tomography: A New Tool on the Horizon for Forensic Dentistry

Teeth and bones of calvarium are important structures from a forensic point of view, as they are extremely resilient to destruction or decomposition, even under temperature variations. Radiology is inevitably an important tool in forensic investigations. Maxillofacial radiology provides a considerable amount of information for the identification of remains and evidence in case of legal matters. The advent of cone-beam computed tomography (CBCT) in the arena of maxillofacial 3D imaging has contributed immensely to forensic science such as the age estimation through teeth, analysis of bite marks, determination of race and sex, etc. The advantages of accuracy in imaging the anatomy, digitized technology favoring easier comparison of records and storage of records for a longer period, cost reduction, dose reduction, and easier portability have made it an unavoidable adjunct in forensic investigations. The aim of this paper is to review and highlight the importance of CBCT in successful forensic identification and analysis. This review is written to address the various aspects of CBCT as a recently developed technology that may be very useful in some forensic contexts, based on searches for current studies in the literature using PubMed, Scopus, Web of Science, and Google Scholar databases, to identify studies published since inception to December 2021, with no language restriction. In conclusion, CBCT is an accessible 3D imaging technology with many applications, one of them being in forensic sciences.

Do upper third molars provide more accurate age estimation in the adult based on the pulp-to-tooth ratio than lower third molars? A cone-beam CT study

Introduction

Age-at-death estimation is an essential part of the identification process of individuals in many forensic dentistry cases where identity of the individual cannot be resolved by visual recognition or other means. Dental age estimation in adults is more of a challenge as most teeth complete their development by the age of 18 years.

Aim

This study aims at using the mesio-distal (MD) pulp-to-tooth ratio taken at the cervix of upper third molars (UM3) to estimate age at the time of radiographic imaging.

Materials and Methods

A set of 135 Cone-beam computed tomography (CBCT) radiographs of UM3s for a random sample of 135 Jordanian adults (65 females, 70 males; age range = 18–63 years, mean age = 34.4 years, SD = 11.2 years) were used. Both pulp and tooth MD diameters were measured at the cervix. MD pulp-to-tooth ratios for UM3s were correlated with age.

Results

Statistically significant negative moderate correlation was found between the age of the individual and the cervix MD pulp/tooth ratio (r = −0.516). This indicates that only 26.6% of the variation in age can be explained by the cervix MD pulp-to-tooth ratio.

Conclusions

This study concludes that cervix MD pulp-to-tooth ratio of UM3s, although apparently stronger than that of lower M3s (r = −0.361), is not a sufficiently reliable estimator of age in adults, and this is perhaps attributed to the greater variability in the time line of third molars development.

Radiomorphometric Evaluation of the Frontal Sinus in Relation to Age and Gender in Saudi Population

Background:

Radiographs have been used for forensic identification purpose. At times when only skull remains are found and other means of identification fail, radiographs of skull may be used for identification purpose.

Aim:

The objective of this study was morphometric evaluation of the frontal sinus by using digital posteroanterior skull radiograph in relation to age and gender and to establish its forensic importance.

Materials and Methods:

The study was conducted at Alfarabi Private College for Dentistry and Nursing, Jeddah, Kingdom of Saudi Arabia. It included 400 subjects (200 males and 200 females), aged 14–70 years. Radiographs of the individuals were taken by digital radiography, and morphometric evaluation of frontal sinus was carried out by using Adobe Photoshop CS3 Extended.

Results:

Unilateral absence of sinus was noted in 2.5% males and 1.5% females. Bilateral absence was noticed in 2% males and 0.5% females. Right and left frontal sinus symmetry was seen in 83.20% of the individuals. The left-dominated asymmetry was observed in 6.98% individuals. The right-dominated asymmetry was observed in 9.82% individuals. Simple logistic regression analysis of gender by different variables showed right width and left width, which are most suited regressors for sex determination. The rate of accuracy in classification of males and females varied from 67.70% to 95.90%. Stepwise multiple regression analysis of estimation of age by different variables showed right sinus height is the best predictor of age.

Conclusion:

In this study, the radiographic images of the frontal sinus showed significant morphological difference in relation to age and gender in Saudi population. On the basis of this evidence, it is proposed that the morphologic evaluation of frontal sinus can be used for personal identification.

The use of panoramic images for identification of edentulous persons

The aim of this study was to determine if edentulous persons could be identified using panoramic images by: I) investigating the possibility of matching two panoramic radiographs of the same person obtained on two different occasions, II) determining what anatomical features are used as the base for matching, III) investigating if oral and maxillofacial radiologists (OMR) and dentists who were not oral and maxillofacial radiologists (NOMR) differed in their ability to match the images, and IV) determining if the time elapsed between the images affected the results or the confidence of the match. Panoramic image pairs from 19 patients obtained on two different occasions were included, plus 10 images from other edentulous patients. The time elapsed between the image pairs varied between 4 months and 6 years. Four OMR and four NOMR were asked to match the image pairs depicting the same patient. The participants marked each match as "certain", "likely", or "possible" and what anatomical structure they used for matching. The OMR group correctly matched 100% of the images and the NOMR group correctly matched 96%. The anatomy of the mandible was most often used for matching. The OMR group was more certain in their decisions than the NOMR group. The time elapsed between the examinations did not affect the result. In conclusion, panoramic images can be used to identify edentulous patients. Both OMR and NOMR could identify edentulous individuals when only panoramic radiographic images were available and the OMR were especially confident in the identification process.

Automatic frontal sinus recognition in computed tomography images for person identification

In many cases of person identification the use of biometric features obtained from the hard tissues of the human body, such as teeth and bones, may be the only option. This paper presents a new method of person identification based on frontal sinus features, extracted from computed tomography (CT) images of the skull. In this method, the frontal sinus is automatically segmented in the CT image using an algorithm developed in this work. Next, shape features are extracted from both hemispheres of the segmented frontal sinus by using BAS (Beam Angle Statistics) method. Finally, L₂ distance is used in order to recognize the frontal sinus and identify the person. The novel frontal sinus recognition method obtained 77.25% of identification accuracy when applied on a dataset composed of 310 CT images obtained from 31 people, and the automatic frontal sinus segmentation in CT images obtained a mean Cohen Kappa coefficient equal to 0.8852 when compared to the ground truth (manual segmentation).

Guidelines for reproducing geometrical aspects of intra-oral radiographs images on cone-beam computed tomography

Human identification requires comparison of individual traits of a person, depending on the availability and reproduction of antemortem (AM) records. If there is no presumed identity or AM exams are not available for comparison, the production of postmortem (PM) records is impaired. The purpose of this research is to describe and test standards to enable the comparison of antemortem periapical radiographs to images extracted from the manipulation of postmortem CBCT exams in multiple identification simulations in a randomized blind study. In a simulation, 20 CBCT images from dry skulls were used as PM records and 3 periapical radiographs (total of 60) that were randomized and blinded from the first examiner. In each case, an intentional incidence error of 10° was added in four different directions. Three points were selected in the AM radiograph, and the angle, linear measurements and proportion between these distances were collected. The AM data were used to mathematically find similar image geometry on a CBCT maximum intensity projection. Possible identification by superimposition was achieved in all cases, and statistical analysis proved the success in the reproduction of angular and length proportion using CBCT incidence manipulation. Significant reproducibility was also observed on intra- and inter-observer tests. In conclusion, the images extracted from CBCT could be compared to any periapical radiographs by superimposition, providing acceptable evidence to establish human identification. The application of this protocol is suitable for forensic practices with the high level of reproducibility and could be used as PM record when no AM records are available at the time of the exam.

Human identification study by means of frontal sinus imaginological aspects

The objective of this study was to evaluate the applicability of human identification parameters, established by Tatlisumak et al. (2007), by means of cone-beam computed tomography and extraoral radiographs of the frontal sinus region. From a total of 58 dry skulls, 26 were selected. Posteroanterior, profile cephalometric radiographs and cone-beam computed tomography images were acquired, adopting a specific method for reproducibility purposes. The images were evaluated by two examiners, previously calibrated, in a darkened environment and at two distinct sessions, with a minimum of 15 days between them. The characteristics of the frontal sinus were analyzed using the Cohen's kappa test, for categorical variables, and Lin's concordance correlation coefficient (CCC) for continuous variables. Acceptable values of inter method variability for the categorical variables were found, while same cannot be told for continuous variables. The parameters evaluated for the frontal sinus on extraoral radiographs and cone-beam computed tomographs were mostly concordant, with the exception of three. Categorical and discrete variables showed an intra- and interexaminer concordance ranging from good to perfect, and the quantitative continuous variables showed concordance ranging from moderate to excellent. The parameters examined are applicable and reproducible using multiplanar reconstructions of cone-beam computed tomography and extraoral radiographs of the frontal sinus.

Reliability of frontal sinus by cone beam-computed tomography (CBCT) for individual identification

Analysis of the frontal sinus is an important tool in personal identification. Cone beam-computed tomography (CBCT) is also progressively replacing conventional radiography and multi-slice computed tomography (MSCT) in human identification. The aim of this study is to develop a reproducible technique and measurements from 3D reconstructions obtained with CBCT, for use in human identification. CBCT from 150 patients (91 female, 59 male), aged between 15 and 78 years, was analysed with the specific software program MIMICS 11.11 (Materialise N.V., Leuven, Belgium). Corresponding 3D volumes were generated and maximal dimensions along 3 directions (x, y, z), X M, Y M, Z M (in mm), total volume area (in mm(3)), V t, and total surface (in mm(2)), S t, were calculated. Correlation analysis showed that sinus surfaces were strongly correlated with their volume (r = 0.976). Frontal sinuses were separate in 21 subjects (14 %), fused in 67 (44.6 %) and found on only one side (unilateral) in 9 (6 %). A Prominent Middle of Fused Sinus (PMS) was found in 53 subjects (35.3 %). The intra- (0.963-0.999) and inter-observer variability (0.973-0.999) showed a great agreement and a substantial homogeneity of evaluation.

Estágio de mineralização dos terceiros molares e sua relação com a idade cronológica: uma amostra da população do Centro-Oeste do Brasil

INTRODUÇÃO: Nos últimos anos, alguns estudos foram conduzidos com o objetivo de avaliar a aplicabilidade da análise de desenvolvimento dos terceiros molares na estimativa da idade humana. No entanto, há escassez de trabalhos em amostras populacionais da região Centro-Oeste do Brasil.OBJETIVO: Avaliar a relação entre estágio de desenvolvimento dos terceiros molares inferiores e a idade cronológica de indivíduos da região Centro-Oeste do Brasil.MATERIAL E MÉTODO: Trata-se de um estudo observacional transversal, com uma amostra constituída por 120 prontuários de pacientes entre 5 e 22 anos de idade, dos gêneros masculino e feminino, atendidos entre os anos de 2007 e 2012 na nossa instituição. O estágio de desenvolvimento dos terceiros molares inferiores foi avaliado pelo método descrito por Nolla e relacionado à idade cronológica do indivíduo por meio de regressão linear, sendo considerados significantes valores de tendência linear entre 0 e 1.RESULTADO: Pode-se observar que tanto a amostra composta por pacientes do gênero masculino (R2 = 0,7495) quanto do feminino (R2 = 0,8507) apresentaram correlação linear entre o estágio de desenvolvimento dos terceiros molares inferiores e a idade cronológica. Notou-se, ainda, que os estágios de desenvolvimento coincidiram com idades semelhantes em ambos os gêneros.CONCLUSÃO: Há relação entre a idade cronológica e o estágio de desenvolvimento dos terceiros molares inferiores na amostra estudada. Estes dados sugerem que este tipo de análise deve ser individualizada, de acordo com as características populacionais da região.