Sex classification of first molar teeth in cone beam computed tomography images using data mining

OBJECTIVE

The teeth have been used as a supplementary tool for sex differentiation as they are resistant to post-mortem degradation. The present study aimed to develop a new novel informatics framework for predicting sex from linear tooth dimension measurements achieved from cone beam computed tomography (CBCT) images.

METHOD AND MATERIALS

A clinical workflow using different machine learning methods was employed to predict the sex in the present study. The CBCT images of 485 subjects (245 men and 240 women) were evaluated for sex differentiation. Nine parameters were measured in both buccolingual and mesiodistal aspects of the teeth. We applied our dataset to Naïve Bayesian (NB), Random Forest (RF), and Support Vector Machine (SVM) as classifiers for prediction. Genetic feature selection was used to discover real features associated with sex classification.

RESULTS

The 10-fold cross-validation results indicated that NB had higher accuracy than SVM and RF for sex classification. The genetic algorithm (GA) indicated that the model could fit the data without using the enamel thickness and pulp height. The average classification accuracy of our clinical workflow was 92.31 %.

CONCLUSION

The results showed that NB was the best method for sex classification. The application of the first molar teeth in sex prediction indicated an acceptable level of sexual classification. Therefore, these odontometric parameters can be applied as an additional tool for sex determination in forensic anthropology.

Root Dentin Translucency and Forensic International Dental Database: Methodology for estimation age-at-death in adults using single-rooted teeth

Estimation of the age-at-death in adults is essential when the identification of deceased persons with unknown identity is required in both humanitarian and judicial contexts. However, the methodologies and the results obtained can be questioned. Various efforts have been developed to adjust procedures to specific populations, always seeking the precision and accuracy of the methodologies. It is known that the estimation of the age-at-death in adults coexists with wide margins of error, due to several reasons, including but not limited to statistical problems, the size of the sample or the physiological process of aging. This research focuses on a degenerative indicator of the dentin (Root Dentin Translucency) and its combination with Periodontal Height (PH) following the Lamendin's technique for estimation of the age-at-death in adults. The main objective of this research was to demonstrate the applicability of a Bayesian model based on a Forensic International Dental Database (FIDB) that include Root Translucency Height (RTH) and PH as a method to age-at-death in adults. The conclusion of this research was that the combined both indicators become a generalizable age-at-death in adults model for all human populations, where the Bayesian method would offer optimal results in any population. In this way, those populations that do not have had the possibility of validating a specific procedure, now have the opportunity to apply a valid method for estimating age-at-death in adults to global scope.

Analysis of 100 most cited articles on forensic odontology

OBJECTIVES

Bibliometric analysis of best-cited papers brings awareness about the influential publications and trends in the literature on a particular topic. This will help not only the researchers and academicians but also the students for selecting quality landmark articles. With this view in mind a bibliometric analysis was performed to identify the 100 top-cited papers on Forensic Odontology (FO) in the literature.

MATERIALS AND METHODS

A search was performed using Scopus database in August 2019. The articles were further reviewed and basic standard information related to bibliometric analysis was recorded.

RESULTS

The 100 most cited articles were published from 1985 to 2014 (77% published after 2001). The most frequently cited article received 259 citations, whereas the least received 31 (mean citations 58.78 ± 33.14). There were 16 different journals with Forensic Science International having the most number of articles (n = 36). One author had 16 articles while 8 authors had 4 or more articles published in the top 100 list. Belgium was the country with most number of articles (n = 17) followed by United States (n = 16). In terms of document type, 87 were original research, 7 conference papers and 6 reviews. Five organizations funded 5 of the top 100 articles. Katholieke Universiteit Leuven, Belgium affiliated the most documents (n = 16). Majority of the papers were related to age estimation (46) followed by victim identification (30), mass disaster (9), bite mark analysis (8), sex determination (5), race determination (4), dental DNA analysis (3), palatal rugae pattern (2) and lip prints (1).

CONCLUSION

This is first of its kind citation analysis of the 100 most cited articles in the field of FO. The results of this paper will help the researchers, academicians and students for appropriate article referrals.

Application of intraoral scanner to identify monozygotic twins

BACKGROUND

DNA base identification is a proper and high specificity method. However, identification could be challenged in a situation where there is no database or the DNA sequence is almost identical, as in the case of monozygotic (MZ) twins. The aim of this study was to introduce a novel forensic method for distinguishing between almost identical MZ twins by means of an intraoral scanner using the 3D digital pattern of the human palate.

METHODS

The palatal area of 64 MZ twins and 33 same-sex dizygotic (DZ) twins (DZSS) and seven opposite-sex dizygotic twins (DZOS) were scanned three times with an intraoral scanner. From the scanned data, an STL file was created and exported into the GOM Inspect® inspection software. All scans within a twin pair were superimposed on each other. The average deviation between scans of the same subject (intra-subject deviation, ISD) and between scans of the two siblings within a twin pair (intra-twin deviation, ITD) was measured. One-sided tolerance interval covering 99% of the population with 99% confidence was calculated for the ISD (upper limit) and the ITD (lower limit).

RESULTS

The mean ISD of the palatal scan was 35.3 μm ± 0.78 μm. The calculated upper tolerance limit was 95 μm. The mean ITD of MZ twins (406 μm ± 15 μm) was significantly (p < 0.001) higher than the ISD, and it was significantly lower than the ITD of DZSS twins (594 μm ± 53 μm, p < 0.01) and the ITD of DZOS twins (853 μm ± 202 μm, p < 0.05).

CONCLUSION

The reproducibility of palatal intraoral scans proved to be excellent. The morphology of the palate shows differences between members of MZ twins despite their almost identical DNA, indicating that this method could be useful in forensic odontology.

Emulating Odontolegal Practice: A Paradigm Shift in the Dental Practice Laying More Emphasis on Dental Records-A Perspective and Contemporary Study with a Reality Check

Aim

This study was conducted to evaluate the knowledge and the awareness on odontolegal practice with more emphasis on significance of maintaining dental records by the oral health professionals.

Materials and methods

A cross-sectional study was carried out among 120 dental practitioners of Jammu and Kashmir, Himachal Pradesh, Delhi, Punjab, Gujarat, and Odisha. A questionnaire was designed to assess their practice and knowledge regarding the importance of maintenance of dental records and the knowledge about dental jurisprudence. Total 120 questionnaire samples were distributed among dental health professionals, and the data obtained were studied and formulated for significance of dental records.

Results

Feedback obtained was then analyzed. Seventy percentage of the dentists are not maintaining clinical records of their patients and 20% of the dentists acknowledged that they are not keeping or maintaining dental records like X-rays and cast models of their patients. Eighty percentage of dentists were not known to the ethical importance of dental record, i.e., for how long they have to maintain records of their patients and other details.

Conclusion

This study concludes that the oral health professionals lacked the knowledge and awareness about odontolegal aspects and the significance of maintaining dental records. It was observed that there was insufficient knowledge about medicolegal systems and there is a need to bring awareness and knowledge of the same in the dental fraternity.

Clinical significance

With the increasing use of medical insurance and subsequently mediclaims, negligence suits, scientific evaluation, and research purposes, and health planning, etc., the “dental records itself have evolved as a separate science and therefore needs to be considered in the curriculum for dental students as this would introduce the concept for application in their future practice, thus avoiding legal complications in the future.”

How to cite this article

Kaul B, Gupta S, Vaid V, et al. Emulating Odontolegal Practice: A Paradigm Shift in the Dental Practice Laying More Emphasis on Dental Records—A Perspective and Contemporary Study with a Reality Check. Int J Clin Pediatr Dent 2020;13(3):217–220.

Dental age estimation in children affected by juvenile rheumatoid arthritis

Abstract

Dental root calcification has proven to be a reliable biological evidence to estimate chronological age of children. The development of structures usually examined in the age estimation forensic practice (e.g. skeleton, teeth) is supposed to be influenced by diseases and nutritional, environmental, ethnic, and ultimately even socioeconomic factors. This research aims to study the age estimation in children affected by juvenile rheumatoid arthritis (JRA) with and without steroids treatment and compared with healthy subjects.

Material and methods

Dental age estimations based on 752 OPGs, 420 girls and 332 boys, aged from 3.3 to 15.99 years, were provided by applying Demirjian and Willems’ original methods. Of the whole sample, 103 individuals were affected by JRA and 40 received a continuous corticosteroid therapy, over 1 year long.

Conclusions

Willems’ and Demirjian’s original methods, as methods commonly applied to estimate age for sub-adults with unremarkable medical history, can be used for medico-legal purposes to children affected by JRA. Willems’ method tended to underestimate age while Demirjian’s method resulted to be prone to overestimation for both healthy and JRA-affected children. JRA showed to have no influence on root calcification process even in children that received steroid treatment for 1 year or longer.

Electronic supplementary material

The online version of this article (10.1007/s00414-020-02395-w) contains supplementary material, which is available to authorized users.

Forensic odontology: The prosthetic ID

The term “forensic science” involves forensic (or forensis, in Latin), which means a public discussion or debate. In a more modern context, however, forensic applies to courts or the judicial system. Combine that with science, and forensic science means applying scientific methods and processes to solving crimes. People can be identified by their fingerprints, foot creases, and from traces of their DNA from blood, skin, hair, saliva, and semen by DNA analysis. However, in situations where these records are unavailable or unusable due to the nature of the disaster, the dental records and aids prove to be useful for victim identification. This article aims at highlighting the importance of the dental records and the forensic odontology in the accurate and efficient identification of the conflict victims or deceased to serve as an important adjunct to the forensic medicine in a simplified manner.

Automatic human identification from panoramic dental radiographs using the convolutional neural network

Human identification is an important task in mass disaster and criminal investigations. Although several automatic dental identification systems have been proposed, accurate and fast identification from panoramic dental radiographs (PDRs) remains a challenging issue. In this study, an automatic human identification system (DENT-net) was developed using the customized convolutional neural network (CNN). The DENT-net was trained on 15,369 PDRs from 6300 individuals. The PDRs were preprocessed by affine transformation and histogram equalization. The DENT-net took 128 × 128 × 7 square patches as input, including the whole PDR and six details extracted from the PDR. Using the DENT-net, the feature extraction took around 10 milliseconds per image and the running time for retrieval was 33.03 milliseconds in a 2000-individual database, promising an application on larger databases. The visualization of CNN showed that the teeth, maxilla, and mandible all contributed to human identification. The DENT-net achieved Rank-1 accuracy of 85.16% and Rank-5 accuracy of 97.74% for human identification. The present results demonstrated that human identification can be achieved from PDRs by CNN with high accuracy and speed. The present system can be used without any special equipment or knowledge to generate the candidate images. While the final decision should be made by human specialists in practice. It is expected to aid human identification in mass disaster and criminal investigation.

Forensic study of mechanical properties of dental fillings after immersion in marine environment

Human identification and postmortem intervals can be difficult to estimate when corpses are found in drowning situations, and forensic odontologists can bring valuable input to forensic science investigations of this type. Studies that simulate real scenarios are crucial for providing parameters that can be used in real cases. The present study created the necessary circumstances, i.e. immersion in a marine environment, to estimate the changes in the mechanical properties (Knoop microhardness, roughness, and color) of various dental fillings (silver amalgam, composite resin, and glass ionomer cement) over different immersion periods of time (one and three months). The silver amalgam fillings showed a significant increase in surface roughness. The composite resin fillings showed statistically significant increases in surface roughness and Knoop microhardness, and the glass ionomer cement showed a significant increase in surface roughness. These results lead to the conclusion that teeth restored with silver amalgam, composite resin, and glass ionomer cement, when subjected to immersion in marine environments, produce different changes in surface roughness, Knoop microhardness, and color properties depending on the length of immersion time. These findings could help in the field of forensic science to accurately estimate immersion time of dead bodies found in marine environments.

A Comparative Evaluation of Three Different Dental Age Estimation Methods in India: A Test of Ethnic Variability

Aim

The present study aimed to evaluate and compare the applicability of Demirjian, Willems, and Haavikko methods of dental age estimation in southeastern (Dravidian ethnicity) and northwestern regions (Aryan ethnicity) of the Indian population.

Materials and methods

The study includes the orthopantomographs (OPGs) of 303 individuals (173 males and 130 females) of age ranging from 5 to 14 years. The participants in the present research were evaluated under two study groups: group I: participants of the southeastern region and group II: participants of the northwestern region. Dental age was calculated using Demirjian, Willems, and Haavikko methods and compared with the chronologic age of each participant. The accuracy of dental age estimation methods was evaluated by mean absolute error. One-way analysis of variance (ANOVA) and Student's t tests were used to test the significant difference between the chronologic age and estimated dental ages.

Results

The Demirjian method showed overestimation, while Willems and Haavikko methods showed underestimation for boys and girls in both the ethnic groups of Indian population. The Willems method of dental age estimation showed comparatively more accurate and reliable results in both the ethnic groups of the Indian population.

Conclusion

The dental age estimation by Demirjian, Willems, and Haavikko methods showed no significant variation between the different ethnicities of the Indian population.

Clinical significance

The present research will be helpful in pedodontic, orthodontic, and forensic investigations for accurate and reliable dental age estimation in different parts of Indian population.

How to cite this article

Chaudhry K, Talwar M, Vanga NRV, et al. A Comparative Evaluation of Three Different Dental Age Estimation Methods in India: A Test of Ethnic Variability. Int J Clin Pediatr Dent 2020;13(1):16–20.

Examination of the radiographic visibility of the root pulp of the mandibular second molars as an age marker

Forensic odontologists often confront with conceptually simple medicolegal question of whether an individual is a juvenile or an adult. The demand for additional research into extending dental age estimation methods in late adolescence is never the less, especially in those who have passed 15 years and are suspected older than 18 years. The present research investigated the regressive dental characteristic, i.e. radiographic visibility of the root pulp in mandibular second molars for the purpose of age assessment, especially for determining the age over 18 years. Nine hundred thirty-six orthopantomograms comprised of 436 males and 500 females aged from 14 to 22 years were examined. Descriptive statistics were performed for each stage in both sexes. The correlation statistics revealed that there is a strong, positive correlation between the chronological age and root pulp visibility stages. The analysis revealed that stage 0 occurred first at the age of 14 years in both sexes. Stage 1 first occurred at the age of 14.26 years in females and 14.74 years in males. Stage 2 was first achieved at the age of 18.6 and 15.2 years in males and females, respectively. The suitability of the studied characteristics in mandibular second molars for age estimation could be confirmed but of limited value. The presence of this stage 2 root pulp visibility in male subjects represents a potential criterion for indicating the age over 18 years. In future studies, the pattern of secondary dentin formation in other tooth types should be investigated.

Profound approach to check legitimacy of an old technique used to gauge palatal rugae

Aims

The present study aimed at assessing two fixed points of reference from where the mesial and distal point of all rugae can be measured so that the exact movement of particular rugae in any direction can be evaluated and assessing the changes in the palatal rugae after orthodontic treatment.

Methods

A longitudinal study conducted among a sample of 20 (8 male and 12 female) adult patients. Pre- and post-orthodontic treatment casts of patients were obtained from the Department of Orthodontics College of Dentistry Jazan University. Antero-posterior linear distances (Technique I) between medial and lateral points of primary, secondary and tertiary rugae were measured. Also, the transverse linear distance (Technique II) between medial and lateral points of right and left rugae were measured. Technique III involved marking two fixed points and using these two points a third point is located on the medial or lateral end of rugae of right and left side in pre and post-treatment orthodontic casts. The independent sample t-test was employed to compare gender. Difference between the pre- and post-treatment mean values were checked by the paired t-test.

Results

Technique III successfully showed the statistically significant difference (P ≤ 0.05, 95% CI) in the overall pre and post-treatment values on the patients' cast (N = 20) which was not observed with a technique I and technique II.

Conclusion

The triangle created by the three reference points in the technique III was able to identify the changes in the palatine rugae more precisely than the technique I and Technique II.

Dental autopsy recommendations in SARS-CoV-2 infected cases

Unidentified human remains with unknown medical history can always pose biological hazards to forensic pathologists and odontologists, including hepatitis C, HIV infection, Middle East respiratory syndrome (MERS), hemorrhagic fever viruses such as Ebola, meningitis and now Sars-Cov2. The pandemic of the new coronavirus disease (COVID-19) has reached 185 Countries with an increasing number of deaths. Forensic pathologists and odontologists may find themselves having to perform an identification autopsy to confirmed or suspected Sars-Cov2 positive deaths. By respecting the entire set of universal precautions and recommendations the highlighted risks can be minimized, and best practice in human identification should always be a priority for human rights of the dead. The following article is a summary of the recommendations for conducting dental autopsies and management of suspected COVID-19 cases.

Odontological identification dental charts based upon postmortem computed tomography compared to dental charts based upon postmortem clinical examinations

Since the beginning of this century, the use of postmortem computed tomography (PMCT) in forensic autopsies has increased. In this study we examined how similar dental charts created using PMCT as a solitary examination mode were to dental charts created using the conventional method of a clinical inspection including intraoral radiographs. A total of 100 previously performed dental identification cases were retrospectively included in the study. For each case, a dental chart was created solely based upon PMCT. The PMCT based dental chart was subsequently compared with the chart created from the previous conventional identification examination. Based upon the accuracy, sensitivity and specificity values PMCT performed very well compared to the conventional method in the identification concerning presence or absence of teeth, the presence of crowns, bridges and endodontic treatments as well as the presence and types of fillings. PMCT performed poorly concerning the extension of fillings and identification of small, tooth-colored fillings. The use of PMCT is a valuable supplement to the conventional methods available for forensic odontologists and may be of great value for initial screening in mass fatalities.

Detection of DNA adduct 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a toxicity bioindicator to the effects of nickel on Ni-Cr alloy prosthesis users

Previous studies have suggested that exposure to Ni from Ni-Cr alloys can affect the human body through oxidative stress. The present study discusses the effect of nickel from Ni-Cr alloy prostheses on the formation of DNA Adduct 8-Hydroxy-2′-Deoxyguanosine (8-OHdG), evaluated based on creatinine and 8-OHdG concentrations in urine, determined with LC-MS/MS, for a Ni-Cr alloy user group and a never-user control group. The mean creatinine and 8-OHdG concentrations were not significantly different between the test groups, although highest levels were observed for the in the Ni-Cr user group. It is suggested that samples with relatively high creatinine and/or 8-OHdG levels are further studied in more detail for stability of concentrations and for the effect of contributing factors.

Age estimation of Brazilian individuals using the London Atlas

OBJECTIVE

The objective of the present study was to evaluate, for the first time, the applicability of the London Atlas method for age estimation on a sample of Brazilian population.

DESIGN

The study consisted of archived dental panoramic radiographs (n = 288) of individuals aged between 5 and 23 years. Radiographs were assessed using the London Atlas method to determine the developmental and eruption stages of all teeth on each sides of each jaw separately, and also to make an age estimation.

RESULTS

There was no significant differences between the right and left sides of the jaws (p = 0.31 for males and p = 0.65 for females). An overestimation of age occurred more likely in the female sample when compared to the male sample. Three age groups, 20.5, 18.5 and 19.5 years, presented the highest values ​​of mean absolute difference found in the whole sample.

CONCLUSION

The London Atlas of age estimation performed well in general and good viability in an expert context, with most age groups showing age differences lower than two years of age, however it is necessary that it be applied with caution in certain age groups, especially when the third molar is used as a decision tooth for age estimation. Therefore, it is recommended to use more than one method for assessing the age in those age groups.

Effect of high temperatures on teeth fixed with an orthodontic bracket. An in vitro study

In cases of incineration, where the identification of victims by conventional methods is impossible, teeth and dental materials become an available source of evidence - thanks to their ability to resist high temperatures. Currently, there is no experimental research to determine the behavior of the bracket and the dental structure when it is attached to the tooth after being exposed to high temperatures. An experimental in vitro study was carried out on 60 upper and lower premolar teeth (30 with a cemented bracket and 30 teeth without a bracket) that were exposed to six temperature ranges (200 °C, 400 °C, 600 °C, 800 °C, 1000 °C and 1200 °C). With the help of an Optiks® binocular stereomicroscope, macroscopic changes were described for each temperature; in addition, the mesio-distal diameter of the crown of the teeth and the bracket were measured before and after the incineration. A comparison of the diameters between the groups [the experimental group and the control group] and between the different temperatures was made. Both teeth, with brackets and without brackets showed macroscopic changes, such as fissures, cracks, fragmentation, enamel bursting and enamel and dentin separation according to the temperature range exposed. The detachment of the bracket was presented at 600 °C - leaving a mark on the dental surface. At above 1000 °C, the crown of the tooth with bracket acquired a pink color and the surface of the bracket became rough and opaque. At above 400 °C, both groups experienced an expansion in the crown dimension without significant differences. The results of this research suggest that teeth with attached brackets are equally resistant as the teeth without brackets, and that the adhesion of these attachments to the dental structure leave characteristics that allow them to be differentiated from teeth without braces -as well as suggesting the orientation to the temperature exposure.

Prediction Formula of Permanent Canine and Premolar Eruption in Mixed Dentition Patients at Universitas Airlangga, Dental Hospital Surabaya, Indonesia

Background

The eruption of permanent canine, first and second premolars need to be predicted because they are erupted last, before the eruption of permanent first and second molars, in order to estimate the available space in orthodontic treatment.

Aim

This study aimed to predict the eruption of permanent canine, first and second premolars in mixed dentition.

Materials and Methods

A cross sectional clinical observation was conducted in 21 subjects of 13 males nad 8 females with the age range of 8-12 years old. Their panoramic radiographs were used to create a prediction formula of permanent canine and premolars. The independent variables of this research are age, weight, height, birth weight, birth height, period of breastfeeding, and vertical distance of eruption. Data were analyzed by coefficient of multiple correlation followed by multiple linear regression analysis.

Results

The prediction formula is as follows: Y = -5107 + 1645 X ₁ + 078 X ₂, where Y is the time of eruption, X ₁ is the height, and X ₂ is the vertical distance of eruption.

Conclusion

The prediction formula is useful for serial extraction in orthodontic treatment. It is also useful for forensic odontology, especially in the determination or identification of ages. It is recommended to be implemented in the science of development, especially in orthodontics and forensic odontology.

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.

Preliminary analysis testing the accuracy of radiographic visibility of root pulp in the mandibular first molars as a maturity marker at age threshold of 18 years

Forensic age estimation, after completion of third molar mineralization, regressive features such as apposition of secondary dentin, which is seen as narrowing of the pulp space in the radiographs, can be used as an alternative. In the present study, we explored the radiographic visibility of the root pulp of mandibular first molars using stage classification of Olze et al. (Int J Legal Med 124(3):183-186, 2010) in a sample of 901 orthopantomograms (404 males and 497 females) of south Indian origin with age ranging from 14 to 22 years. Descriptive statistics for the stages according to age was performed for both sexes separately. The strength and direction of the relationship between the chronological age and pulp visualization stages was tested using spearman's rho correlation statistics. The relationship between age and stage attainment showed statistical significance for both sexes. A strong, positive correlation was seen between the stage and chronological age. All males and females presenting stage 0 of root pulp visibility were younger than 18 years. If stage 1 is determined, it is highly possible that an individual regardless of sex is younger than 18 years. Stage 2 was attained in 79.6% males and 83.1% females who were at least 18 years. One hundred percent males and 92.8% females with stage 3 were at least 18 years. The accuracy of this method in mandibular first molars for estimating age threshold of 18 years ranged from moderate to high. However, it is recommended to use this method in conjunction with other age estimation methods.

Transition analysis applied to third molar development in a Danish population

INTRODUCTION

Age assessment based on dental development is often requested in order to assess whether an individual is older or younger than 18 years of age. There are several statistical approaches to estimate age based upon third molar development. The aim of this study was to apply the principles of transition analysis (TA) to a Danish reference material and to evaluate whether it was indicated to include a model that allows for logistic non-linearity as opposed to applying a model only allowing for logistic linearity. For this we chose to use the generalized additive model (gam) and the generalized linear model (glm), respectively.

MATERIAL AND METHOD

A cross-sectional sample comprising 1302 panoramic radiographs of Danish subjects in the chronological age range of 13-25 years was included. All present third molars had been scored according to the 10-stage method of Gleiser and Hunt. Each transition from one stage to the subsequent stage was analyzed according to the statistical approach of TA and fitted with both the generalized linear model (glm) and the generalized additive model (gam). In order to assess whether gam or glm was more parsimonious for each transition individually, the Akaikon information criterion (AIC) was applied.

RESULTS

The results emphasized the importance of applying a statistical model that sufficiently captures the spread of the age estimate. The AIC values showed that some transitions were sufficiently described by glm whereas for others the gam curves fitted significantly better.

CONCLUSION

We recommend that for an age assessment tool based on TA, both a fitting allowing for non-linearity and one allowing only for linearity should be included.

Social contribution of forensic odontology in Japan

Half a century has passed since the department for education and research on forensic odontology was established at dentistry-related universities in Japan in 1964. In order to meet the demands of society, the number of universities with a department of forensic odontology increased up until around 2005. In 2007, the Japanese Society of Forensic Dental Science was established, and then a series of reforms such as establishment of the Study Council on Death Cause Investigation in both the National Police Agency and the Cabinet Office of the Japanese government, cabinet decision of enactment and enforcement of new laws on death cause investigation, publication of an article on the Model Core Curriculum of Dental Education, publication of the results of a fact-finding survey on education and research on forensic odontology conducted by the Ministry of Education, Culture, Sports, Science and Technology, inclusion of questions about forensic odontology in the National Board Dental Examination, and compilation of a database on dental findings by the Ministry of Health, Labor and Welfare, proceeded in succession. We introduced the half century of forensic odontology in Japan in chronological order.

Accuracy of the lower third molar radiographic imaging to estimate age among Ugandan young people

OBJECTIVE

Dental development is a useful method for age estimation. Although third molar eruption is commonly used to estimate age in Uganda, it is reported to be unreliable because of external influences. The more reliable radiographic techniques have inter-ethnic differences but data from sub-Saharan Africa are limited regarding estimating age in young adults. This study, therefore, aimed at determining the accuracy of Demirjian's classification of the lower third molar, a common dental age estimation method, in estimating key ages in a Ugandan population using Ugandan references. Dental records of 1021 Ugandans aged 10-22 years were assigned to two groups; reference and test. The reference data was retrieved from a database of a previous bigger research project.

RESULTS

The overall sample population comprised of 514/1021 (50.3%) males. The mean age was 15.8 (3.6) years. No significant sex differences in dental age were established in the reference sample (520 records). Accuracy values (area under the curve) at the 12-, 14-, 16- and 18-year cut-offs were between 0.83 and 0.90 using the test sample (501 records). The results suggest that Demirjian's classification of the lower third molars is a useful method for age estimation in the young urban Ugandan population in the 10-22-year age-group.

Age estimation using canine pulp volumes in adults: a CBCT image analysis

Secondary dentine deposition is responsible for the decrease in the volume of the pulp cavity with age. Therefore, the volume of the pulp cavity can be considered as a predictor for estimating age. The aims of this study were to investigate the relationship strength between canine pulp volumes and chronological age from homogenous (approximately equal numbers of individuals in each age range) age distribution and to assess the effect of sex as predictor in age estimation. This study was performed on 719 subjects of Pakistani origin. Cone beam computed tomography images of 521 left maxillary and 681 left mandibular canines were collected from 368 females and 349 males aged from 15 to 65 years. Planmeca Romexis® software was used to trace the outline of the pulp cavity and to calculate pulp volumes. Regression analysis was performed to assess the correlation between pulp volumes considering with and without sex as a predictor with chronological age. The obtained results showed that mandibular canine pulp volume and sex have the highest predictive power (R² = 0.33). The relationship between mandibular canine pulp volume and sex with chronological age demonstrates an odd S-shaped non-linear relationship. A statistically significant difference in volumes of pulp was found (p = 0.000) between males and females. The conclusion was that predictions using the pulp volume of the mandibular canine and sex produced the best estimates of chronological age.

Cameriere's third molar maturity index in assessing age of majority: a study of a French sample

Forensic age estimation is a challenging field in forensic sciences because of the increase of migratory flows. Medicolegal age assessment is a key point because it has many implications for authorities. Dental age estimation is an essential part of the global age assessment. The aim of this study was to evaluate and test the accuracy of Cameriere's cutoff values of the third molar maturity index (I3M) in assessing legal adult age of 18 years in a French population. The sample was constituted of 431 orthopantomograms performed between January 2014 and August 2017 on patients aged between 14 and 22 years. The reproducibility and repeatability of the method were high. Age distribution gradually decreases as I3M increases in both sexes. 0.08 seemed to be the best I3M cutoff. For females, the sensitivity and specificity of the test were 74.51% and 88.23%, respectively. The sensitivity and specificity for males were 92.19% and 88.35%, respectively. The accuracies were 80.74% for female, 90.57% for male. Estimated post-test probabilities were 0.879 for female and 0.899 for male. To conclude, the specific cutoff value of I3M ˂ 0.08 may be a useful additional tool in discriminating adults and minors in French population.

Post-mortem computed tomography as part of dental identification - a proposed guideline

PURPOSE

This paper presents a proposed guideline for the use of post-mortem computed tomography (PMCT) during forensic dental identification. Currently, whole-body PMCT is widely used prior to autopsies for the diagnosis of fractures, organ changes, hemorrhages, and for the localization of foreign bodies, but it may also facilitate the odontological identification process in single cases and in cases involving multiple fatalities. Several studies have described the use of PMCT in forensic odontological work, but we have not found any comprehensive set of guidelines on how to perform a forensic odontological examination using PMCT. The aim was to develop guidelines for creating post-mortem dental charts during forensic odontological identification examinations using the standard functions of PMCT.

METHODS

A proposed guideline was developed from 15 selected cases examined at the Section of Forensic Pathology, Department of Forensic Medicine at the University of Copenhagen in Denmark from October 2011 to May 2012. Using the functionalities and three-dimensional (3D) reconstructions of OsiriX DICOM-viewer software (Pixmeo Sarl, Bernex, Geneva, Switzerland) we adjusted the contrast and brightness settings and developed a proposed guideline for creating PMCT-based dental charts. A four-step guideline was produced.

CONCLUSION

In our casework, we are currently using the guidelines proposed herein. The use of PMCT has allowed us to target our clinical examinations, greatly improving their efficiency. Furthermore, PMCT allows the storage of data for later documentation and research. Further research is needed to validate the proposed guideline.

Healing alveolar sockets in skeletonized remains: A report on cases from one month to twelve months post-extraction

The removal of a tooth is a common clinical procedure documented in an individual's dental record. A photographic and radiographic series of healing alveolar ridges/sockets are presented. The history of a documented extraction and a concordant finding of healing alveolar bone could assist in strengthening an association between a set of unidentified remains and an individual.

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.

New model for dental age estimation: Willems method applied on fewer than seven mandibular teeth

Willems method measures the developmental stages of the seven left permanent mandibular teeth and is frequently used for dental age estimation. The aim of this study was to test its accuracy on a large sample of the Croatian population and to develop new models for estimation based on one to seven mandibular teeth. The developmental stages were evaluated on the digital, standardized orthopantomograms of 1868 Croatian children aged 5 to 16. Univariate regression was used for age estimation based on one tooth and regression with forward and backward elimination for selection of the best combination on two to six teeth. Tested in parallel with Willems method, the accuracy of the new models was assessed within intervals of ± 0.5, ± 1, ± 1.5 and ± 2 years and shows the percentage of correct estimations. Using Willems method, the average overestimation was 0.41 years for boys and 0.22 years for girls. Newly developed models that use two to seven teeth proved to be significantly more accurate (p < 0.001). The accuracy of age estimation increases significantly with the number of teeth in a model. Predictably, within the interval ± 0.5 years, a model with three teeth has 3% fewer accurate age estimations than a model including seven teeth. In both theory and practice, Willems method has been considered suitable for age estimation among Croatian children. However, these newly developed models significantly surpass its accuracy. Models using two to seven teeth represent a simple, reliable, and accurate method for age estimation, even in cases with missing mandibular teeth.

Dental age estimation in Somali children and sub-adults combining permanent teeth and third molar development

Estimation of an individual’s age has important applications in forensics. In young individuals, it often relies on separate evaluations of permanent teeth (PT) and third molars (TM) development. Here, we analysed the age prediction performance of combined information from PT and TM in an unusual sample of healthy Somalis, born and living in Finland. PT development was staged according to Demirjian et al. (Hum Biol, 1973) and TM development according to Köhler et al. (Ann Anat, 1994), using panoramic radiographs from 803 subjects (397 males, 406 females) aged 3–23 years. A sex-specific Bayesian age-estimation model for the multivariate distribution of the stages conditional on age was fitted on PT, TM and PT and TM combined. The age-estimation performances were validated and quantified. The approach combining PT and TM only overestimated age with an ME of − 0.031 years in males and − 0.011 years in females, indicating the best age prediction performance.

Forensic Odontology And Dental Status Of Adult Patients Attending The Out Patient Dental Department Of A Tertiary Care Hospital

BACKGROUND

Pakistan is one of the countries where practice of forensic odontology and its record keeping is poor due to which we face difficulty in identification of individuals in disasters and other medicolegal problems. The objectives of this study were to know the status of forensic odontology and to determine the dental status of adult patients attending dental outpatient department of Ayub Teaching Hospital Abbottabad.

METHODS

A cross-sectional Study was carried out from 1st September to 30th September 2018 in the Department of Dentistry, Ayub Teaching Hospital, Abbottabad. A questionnaire was designed including preliminary record, standard dental chart, notation chart and other variables. A sample of 96 patients having all permanent teeth were included and examined. Non-probability convenience sampling was used. Data was collected and analyzed on SPSS.

RESULTS

The sample consisted of 59.4% males and 40.6% females. Mean number of present teeth with sound status was 24±5. Faulty development was found in 14.6% of the patients. Faulty alignment, black/brown stains and attrition were observed in 38.5%, 86.5% and 25% of the patients respectively. No statistically significant association was found (p >0.05) between gender and faulty development, faulty alignment, staining or attrition. Forensic odontological practice and its record are not maintained in the hospital..

CONCLUSIONS

High proportion the patients have black/brown stains. Faulty alignment is more as compared to faulty development. In our study we observed that no odonatological record is maintained in our hospital.

A new method for estimating time since death by analysis of substances deposited on the surface of dental enamel in a body immersed in seawater

The present investigation was performed with the objective of developing a method to estimate how long a corpse had been immersed in water after death (the time since death). Accurate determination of the time elapsed since death may lead to identification of the place of drowning, and therefore, serves not only as a piece of information useful for determination of the cause of death but also leads to prompt identification of the body. The results showed that diatoms attached to the surface of dental enamel increased with prolongation of immersion time in water. Further, as the immersion time increased, the quantity of O, Si, Mg, K, Al, and S detected on the surface of dental enamel increased, while the quantity of the main dental components (Ca and P) that were detected gradually decreased. Based on these results, we calculated a regression formula to estimate the immersion time. Our method is considered to be a breakthrough technique for evaluating the time since death more objectively, compared to the conventional method of determination based on the degree of decomposition of the corpse.

Tongue position and its relation to the cause of death and sequential stages of body decomposition observed during 608 forensic post-mortems

The purpose of this study was to document tongue position and its relation to the cause of death and sequential stages of body decomposition, as observed during the routine forensic pathological examination of bodies. The sample of 608 included all bodies examined by the first and third authors during the period April 2016 to September 2016. Tongue position was recorded in all cases where position of the tongue could be visually determined. The condition of the body was recorded as follows: fresh flaccid, fresh with rigor mortis, early decomposition, and advanced decomposition. The cause of death was recorded where known. The results showed that 86% of all bodies examined did not show a protruded tongue and that 92.8% of the bodies were in a state of fresh rigor mortis. The study also showed that tongue protrusion was more prevalent in certain causes of death, namely, hanging, burning, and drowning, but was never absolute. The authors believe that due to the low numbers of bodies presenting with protruded tongues, this phenomenon has previously been overlooked, the significance thereof underestimated, and the pathophysiology and pathomorphology never fully investigated.

Third molar maturity index for indicating the legal adult age in southeastern France

The estimation of age in living subjects is today a significant issue because of the increase in the situations in which it arises and its legal consequences. In line with the Study Group on Forensic Age Diagnostics of the German Association of Legal Medicine's recommendations, it is based on the concomitant use of physical examination and methods for estimating bone age and dental age. Given the variations between the populations, the use of the latter requires their validation on all the ethnic groups on which they can be used. This aim of this study was to access the interest of the Cameriere's third molar maturity index (I_3M) to indicate if an individual had reached the age of 18 in a sample of individuals from southeastern France. The studied sample consisted of OPTs 339 (184 females and 155 males) subjects aged between 14 and 22 years old. A logistic regression analysis with the adult age and minor age as dichotomous dependent variable and gender and I_3M as predictor variables showed that gender was not statistically significant in discriminating adults and minors. The receiver operating curve (ROC) analysis showed the best discrimination performance of the specific cut-off value of I_3M<0.08 in discriminating adults from minors. The proportion of accurate classification was 0.897 and 0.916 for females and males, respectively. The specificity (Sp) and sensitivity (Se) results for females were 0.962 and 0.813, respectively. Sp and Se for males were 0.953 and 0.871, respectively. The Bayes post-test probability was 0.961 and 0.955 in females and males respectively. Obtained results showed that a cut-off value of I_3M<0.08 may be an additional tool for indicating adult age in the tested population.

Aspartic acid racemization of root dentin used for dental age estimation in a Polish population sample

Precise age determination of unidentified bodies and human remains is one of the essential tasks of forensic science. The aim of this study was to assess the applicability of using the enantiomeric composition of aspartic acid racemization in root and crown dentin for dental age estimation using a Polish population sample. Coronal and root dentin from four teeth groups from the mandible were studied using gas chromatography with mass spectrometry. The results demonstrated a very high correlation between the chronological age and enantiomeric composition in both of the dentin samples. Individual linear equations of root dentin with correlation coefficients between 0.96 and 0.98 and a standard estimation error of ±2.95–4.84 years validated the application of aspartic acid racemization as a significant practical contribution to everyday forensic medical practice. Discrepancies in methodological aspects and modifications that simplify the protocol are presented.

New equations for age estimation using four permanent mandibular teeth in Thai children and adolescents

The purposes of this study were to generate new age estimation equations using two four-teeth methods and to test the accuracy of the resulting equations in comparison with Demirjian and Goldstein four-teeth methods in a Thai population. A sample of 720 digital panoramic radiographs of Thai individuals (360 males and 360 females), aged between 7 and 15 years was randomly selected and assessed for age estimation. The new equations were developed using quadratic regression analysis. The results showed the Thai population-specific equations had a strong relationship between the dental maturity score and the chronological age in both sexes (r = 0.946-0.956). The new equations revealed no statistically significant differences between the estimated and the chronological ages in either sex. On the other hand, Demirjian and Goldstein four-teeth methods showed statistically significant differences between the estimated and the chronological ages in both sexes. Moreover, we found slight differences in the mean absolute error between Demirjian and Goldstein methods and our new equations (0.01 years for males and 0.03 years for females in method I and 0.04 years for males and 0.02 years for females in method II) and the root mean square error between Demirjian and Goldstein methods and our new equations (0.02 years for males and 0.04 years for females in method I and 0.00 years for males and 0.04 years for females in method II). In summary, although Thai population-specific equations provide a slightly increased accuracy in age estimation in Thai children and adolescents, Demirjian and Goldstein methods are still relevant.

Assessment of the most reliable sites in mandibular bone for the best deoxyribonucleic acid yield for expeditive human identification in forensics

Background:

In recent years, the techniques used to identify human remains post accidents, trauma or in case of criminal investigation have been expanded, improved and rendered more complex by the emergence of technologies based on deoxyribonucleic acid (DNA) analysis. In the head and neck area, tooth has been proven to be the best quantitative source for DNA but in certain cases where the mandible specimen is edentulous or the tooth is extensively destroyed with caries, large dental restorations, mobile, or if they show any perimortem or postmortem fractures, sampling of such tooth specimen is usually avoided. In such situations, bone is considered the next best site for DNA analysis. Mandible being the largest, strongest and dense cortical bone is the most prominent facial bone that can be easily disarticulated. It can be analyzed for the best short tandem repeat (STR) segment qualitative amplification using polymerase chain reaction (PCR) technique for forensic analysis which can be used for gender and age determination.

Aim:

The aim of this study is to determine the best site for optimum quantitative and qualitative yield of DNA for amplification using specific and standard STR segment by conventional PCR technique.

Methodology:

Fifteen mandibular samples exposed to different environmental conditions were collected. Bone pieces of 1 cm × 1 cm were cut from each mandible from three sites, i.e., the ramus, angle and body, wherein the genomic DNA was isolated and was subjected to PCR using restricted number of 25 cycles.

Results:

The STR segment D3S1358 from clone RP11-438F9 used for the study showed very good amplification in restricted number of PCR cycles in the ramus region with number of repeats in every 15^th genomic region.

Conclusion:

This study highlights the use of mandibular bone for the expeditive human identification. As per the study, the ramus of the mandible gave high quantitative and qualitative yield of DNA with thick amplification band of the STR segment as compared to the body and angle of the mandible. Thus ramus of the mandible can be preferred over other sites for molecular forensic investigations.

When forensic odontology met biochemistry: Multidisciplinary approach in forensic human identification

When human remains are found, the priority of the investigation is to ascertain the identity of the deceased. A positive identification is a key factor in providing closure for the family of the deceased; it is also required to issue the death certificate and therefore, to settle legal affairs. Moreover, it is difficult for any forensic investigation involving human remains to be solved without the determination of an identity. Therefore, personal identification is necessary for social, legal and forensic reasons. In the last thirty years forensic odontology has experienced an important transformation, from primarily involving occasional dental identification into a broader role, contributing to the determination of the biological profile. In the same way, "DNA fingerprinting" has evolved not only in terms of improving its technology, but also in its application beyond the "classical": helping with the estimation of sex, age and ancestry. As these two forensic disciplines have developed independently, their pathways have crossed several times through human identification operations, especially the ones that require a multidisciplinary approach. Thus, the aim of this review is to describe the contributions of both forensic odontology and molecular biology/biochemistry to human identification, demonstrating how a multidisciplinary approach can lead to a better and more efficient identification.

Age assessment in canine and premolar by cervical axial sections of cone-beam computed tomography

Age estimation in adults is a challenge in both anthropological and forensic situations compared to sub-adults age estimation. The present study explored, for the first time, the cervical zone of single rooted teeth. The deposition of secondary dentin is responsible for a decrease in the volume of the dental pulp cavity with aging, and therefore is often used as an age indicator. The current study aimed at estimating the chronological age among adults by measuring the pulp/dentin area ratio (physiological ratio) by axial sections at cervical region of maxillary canine and mandibular second premolar. The sample consisted of 120 cone beam CT images of 120 Tunisians whose age ranged from 22 to 67, from the database of a private clinic of radiology. The first axial section of chosen teeth without enamel was selected. Linear regression models were derived for canine, premolar and for all variables to predict the age. They indicated that dentin deposition on canine and premolar have almost the same correlation with age (r=-0.838 and -0.837 respectively). The residual standard errors (RSE), when these regression equations applied for the entire sample, were ranged between 8.27, 8.29 and 7.06 for canine, premolar and for all variables respectively. Tested for younger ages (from 22 to 44years) the RSE decreased considerably and thus ranged between 4.32, 4.72 and 4.05. The outcomes of this study show that the physiological ratio is a useful variable for assessing age with a satisfying accuracy.

Morphometric Analysis of Odontometric Parameters for Gender Determination

INTRODUCTION

In contemporary human population, males exhibit larger size of dentition as compared to females. Additionally, these odontometric parameters show variation in members of same species and also show regional variation.

AIM

To evaluate sexual dimorphism of four maxillary odontometric parameters such as Intercanine Width (ICW), Interpremolar Width (IPW), Arch Length (AL) and Combined Width (CW) of six maxillary anterior teeth, to determine percentage of sexual dimorphism of all four odontometric parameters singly or in combination and also to determine sensitivity, specificity and overall accuracy of odontometric parameters for sex determination.

MATERIALS AND METHODS

This cross-sectional study was conducted on 200 subjects (100 males, 100 females). Four odontometric parameters ICW, IPW, AL and CW were measured directly on the subject and the data thus collected was subjected to statistical analysis.

RESULTS

Discriminant statistical analysis (d square test) revealed that all the four odontometric maxillary parameters exhibited greater mean values in males as compared to females. The difference was found to be statistically highly significant (p<0.001) for ICW and IPW for sexual dimorphism. Also, combination of parameters such as ICW, IPW further improved assessment.

CONCLUSION

The study concluded that linear odonotometric parameters ICW, IPW along with AL, CW show significant sexual dimorphism. Hence, odontometric parameters offer simple, reliable and cost-effective way of determining sex in any forensic investigation.

Forensic Odontology: The New Dimension in Dental Analysis

Forensic Odontology a branch of Forensic sciences uses the skill of the dentist in personal identification during mass calamities, sexual assault and child abuse to name a few. This branch not stranger to many has been growing tenfold in its potential and its ability to bring the forlorn to justice where a dental remains is the only available evidence. It's role and importance in the judiciary is fast growing and hence in depth knowledge in this field seems more than justified.

Three-dimensional analysis of the uniqueness of the anterior dentition in orthodontically treated patients and twins

Dental uniqueness can be proven if no perfect match in pair-wise morphological comparisons of human dentitions is detected. Establishing these comparisons in a worldwide random population is practically unfeasible due to the need for a large and representative sample size. Sample stratification is an option to reduce sample size. The present study investigated the uniqueness of the human dentition in randomly selected subjects (Group 1), orthodontically treated patients (Group 2), twins (Group 3), and orthodontically treated twins (Group 4) in comparison with a threshold control sample of identical dentitions (Group 5). The samples consisted of digital cast files (DCF) obtained through extraoral 3D scanning. A total of 2.013 pair-wise morphological comparisons were performed (Group 1 n=110, Group 2 n=1.711, Group 3 n=172, Group 4 n=10, Group 5 n=10) with Geomagic Studio^® (3D Systems^®, Rock Hill, SC, USA) software package. Comparisons within groups were performed quantifying the morphological differences between DCF in Euclidean distances. Comparisons between groups were established applying One-way ANOVA. To ensure fair comparisons a post-hoc Power Analysis was performed. ROC analysis was applied to distinguish unique from non-unique dentures. Identical DCF were not detected within the experimental groups (from 1 to 4). The most similar DCF had Euclidian distance of 5.19mm in Group 1, 2.06mm in Group 2, 2.03mm in Group 3, and 1.88mm in Group 4. Groups 2 and 3 were statistically different from Group 5 (p<0.05). Statistically significant difference between Group 4 and 5 revealed to be possible including more pair-wise comparisons in both groups. The ROC analysis revealed sensitivity rate of 80% and specificity between 66.7% and 81.6%. Evidence to sustain the uniqueness of the human dentition in random and stratified populations was observed in the present study. Further studies testing the influence of the quantity of tooth material on morphological difference between dentitions and its impact on uniqueness remain necessary.

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.

Deciduous neonatal line: Width is associated with duration of delivery

The delivery-related neonatal line (NNL) appears into the enamel of primary teeth and first permanent molars at birth and is a marker of live birth process. It varies in width and its location, is different in each deciduous tooth type, and is indicative of gestation time. It is unclear which triggers determine NNL at birth. Our objective was to investigate the effect of the duration and mode of delivery on NNL width. NNL of 129 teeth, a collection derived from a long-term, prospectively followed population cohort, was measured under light microscope. Altogether, 54 sections with most optimal plane of sectioning were analysed for the duration and mode of delivery. NNL was detected in 98% of the deciduous teeth with the median width of 9.63μm (min 3.16μm, max 27.58μm). A prolonged duration of vaginal delivery was highly significantly associated with a narrower NNL (r=-0.41, p=0.0097). No significant association was found between the width of NNL and mode of delivery (p=0.36). NNL is demonstrable in virtually all deciduous teeth. The width seems to be inversely proportional to the duration of delivery. Causes of the inverse proportion are speculated to result from altered amelogenesis induced by prolonged and intensified delivery-associated stress. Further research is needed to clarify the underlying mechanisms.

Accuracy in the legal age estimation according to the third molars mineralization among Mexicans and Columbians

Objectives

This study aims to assess the accuracy of age estimation according to two cut-off points of Demirjian's developmental stages (G and H) in the wisdom teeth, using panoramic radiographs from Colombian and Mexican teenagers.

Study design

The degree of maturation of the third molars was classified according to Demirjian in 8 stages (from A to H) by a blinded trained assessor. The sensitivity, specificity and efficacy of two cut-off points (G and H) were calculated for both samples.

Results

The orthopantomographies of 316 subjects, 171 Colombians (54.1%) and 145 Mexicans (45.9%), were analyzed. The stage H was found to be the best threshold for detecting juveniles (because the high specificity) in all the third molars assessed. The specificity was higher for lower third molars than for upper third molars, but no asymmetrical discrepancy was noted.

Conclusions

The stage H is the best cut-off point for detecting the adulthood when a high-specificity test is required.

An analysis of dental intercanine distance for use in court cases involving bite marks

High levels of crime in South Africa and the resulting court cases requiring bite mark evidence have necessitated continuous research into the prevalence and interrelationship of recognisable dental features present in bite marks. This study represents the largest data set of descriptive statistics related to intercanine distance, in which the means, standard deviations, medians and interquartile ranges across four racial groups were determined. Intercanine distances were also statistically weighted by determining the common, uncommon and very uncommon values for each of the racial groups. The results of this research show that we can consider any maxillary intercanine distance more than 24.1 mm and less than 43.0 mm to represent a human bite mark. Black males had the largest mean (average) intercanine distance of 36.33 mm (standard deviation 2.49 mm) and white females the smallest mean intercanine distance of 33.4 mm (standard deviation 2.13 mm). The analyses showed statistically significant differences between the mean intercanine distances of different race and gender groupings. The authors do not advocate trying to determine the race or gender from intercanine distances determined, but rather the relevance of the intercanine distances in the specific race and gender groupings. This study makes a meaningful scientific contribution to the presentation of bite mark evidence at a time when subjective opinions need to be replaced with scientific data.

New models for age estimation and assessment of their accuracy using developing mandibular third molar teeth in a Thai population

Age estimation using developing third molar teeth is considered an important and accurate technique for both clinical and forensic practices. The aims of this study were to establish population-specific reference data, to develop age prediction models using mandibular third molar development, to test the accuracy of the resulting models, and to find the probability of persons being at the age thresholds of legal relevance in a Thai population. A total of 1867 digital panoramic radiographs of Thai individuals aged between 8 and 23 years was selected to assess dental age. The mandibular third molar development was divided into nine stages. The stages were evaluated and each stage was transformed into a development score. Quadratic regression was employed to develop age prediction models. Our results show that males reached mandibular third molar root formation stages earlier than females. The models revealed a high correlation coefficient for both left and right mandibular third molar teeth in both sexes (R = 0.945 and 0.944 in males, R = 0.922 and 0.923 in females, respectively). Furthermore, the accuracy of the resulting models was tested in randomly selected 374 cases and showed low error values between the predicted dental age and the chronological age for both left and right mandibular third molar teeth in both sexes (-0.13 and -0.17 years in males, 0.01 and 0.03 years in females, respectively). In Thai samples, when the mandibular third molar teeth reached stage H, the probability of the person being over 18 years was 100 % in both sexes.

Dental development in patients with agenesis

AIM

Recent research concerning tooth development and dental agenesis suggests that specific genes are associated with agenesis, and that these genetic factors could also cause delayed dental development of the remaining teeth. The objective of this study was to evaluate whether dental development of patients with agenesis is delayed, compared to a control group.

SUBJECTS AND METHOD

Panoramic radiographs of 1145 patients with dental agenesis were collected (452 males, 693 females) aged 6.2 to 24.8 years. The control group included 2032 panoramic radiographs (977 males, 1055 females) aged 6.0 to 24.4 years. A total of 3177 orthopantomograms were staged according to Demirjian. All left permanent teeth present in the mandible (except third molars) were considered. In order to evaluate the difference between patients with and without agenesis, a developmental score (DS) was calculated. The association between the DS and the number of agenetic teeth was evaluated with a Spearman correlation.

RESULTS

Based on the DS, patients with agenesis have a delayed development compared to patients in the control group (p < 0.0001). Within the agenesis group, there is a weak relation between the number of agenetic teeth and the DS: the higher the number of teeth with agenesis, the lower the DS (p < 0.0001 and p = 0.06 for females and males, respectively).

CONCLUSION

The obtained results can be an important factor for treatment planning in patients with dental agenesis. Moreover, the presence of agenesis needs to be taken into account when using age estimation methods based on permanent tooth development.

Forensic dentistry: Adding a perio 'scope' to it!

Human identification during mass disasters using the stereotyped techniques such as fingerprint analysis is a cumbersome task. With a view to overcome this predicament, dental evidence of the deceased has gained importance in the recent years. Various branches of dentistry have augmented forensic research through innumerable scientific contributions. The following narrative review of literature aims to summarize the findings of studies that reported periodontal associations or potential associations that could play a role in forensic research. It is designed to inspire the “perio-society” to lend a helping hand to forensic odontology.

Correlation of calcification of permanent mandibular canine, mandibular premolars, and permanent mandibular first and second molars with skeletal maturity in Indian population

Context:

Morphological variation in children can be understood by the knowledge of growth and development. The state of dental development can be used in forensic odontology to ascertain the age of an unidentified child.

Aims:

This study aims to investigate the relationship of the stages of calcification of the permanent mandibular canine, mandibular premolars, and permanent mandibular first and second molars with skeletal maturity using panoramic and hand–wrist radiographs.

Settings and Design:

This descriptive work was designed as a cross-sectional study.

Materials and Methods:

The study was conducted on 300 healthy subjects (150 males and 150 females) ranging 7–20 years of age. Demirjian's method and Björk, Grave, and Brown's method were used to correlate teeth calcification and skeletal maturity, respectively.

Statistical Analysis Used:

Descriptive statistics and Spearman's rank correlation coefficient were used.

Results:

1. Correlation coefficients between the skeletal maturity stages and the developmental stages of the five teeth ranged 0.461–0.877 for females and 0.480–0.790 for males. 2. The second molar showed the highest and the first molar showed the lowest relationship for female and male subjects in the Indian population.

Conclusions:

The findings of this study indicate that tooth calcification stages might be clinically used as a maturity indicator of the pubertal growth period.