Sex assessment by molar odontometrics in North Indian population

How teeth can be used to estimate sexual dimorphism? A scoping review

INTRODUCTION

Teeth are biological structures with a high degree of hardness, density, calcification, and capacity to adapt to extrinsic factors at physical, biological, and physiological levels. Subsequently, they resist for a longer period in deteriorating environmental conditions. With dental analysis, it is possible to acquire biographical data about a person. The aim of this scoping review was to identify publications using human teeth tissues to estimate sexual dimorphism.

METHODS

The scoping review was carried out in the following databases: Jstor, Scielo, Science Direct, PubMed, and Scopus, using ten search strategies in English and guaranteeing completeness and reproducibility of the phases stipulated in the PRISMA guide.

RESULTS

143 studies on sexual dimorphism based on dental tissue traits were included, of which 40.6% (n = 58) were done in Asia and 27.2% (n = 39) in America. 80% of the studies (equivalent to 114 articles) focused their observations and measurements on the dental crown; 4.2% in enamel, dentin, and pulp together; 3.5% in dental pulp; 2.1% in the entire tooth; 2.8% in enamel, root, and the enamel-cementum junction, and only 0.7% in dentin and pulp. In addition, 92.3% of the studies used metric methods, while only 4.9% and 2.8% used biochemical and non-metric method respectively.

CONCLUSION

For sexual dimorphism establishment, enamel has been the most analyzed dental tissue in permanent canines and molars mainly. Likewise, the most widely and accurately used methods for this purpose are the metrics, with the odontometry as the most implemented (intraoral or by using dental plaster models, digital scanning or software) with prediction percentages ranging from 51% to 95.9%. In contrast to biochemical methods, that can achieve the highest precision (up to 100%), the non-metric methods, to a less extent, reported prediction percentages of 58%.

Use of dimensions in posterior dentition for sex estimation in forensic contexts: A systematic review and meta-analysis

OBJECTIVE

This study assessed the validity of dimensions in posterior dentition for sex estimation in forensic contexts.

DESIGN

A systematic review was established following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). After assessing the risk of bias and methodological quality with the QUADAS-2 system, the data were subjected to statistical tests for a meta-analysis of diagnostic accuracy and I2 to verify the heterogeneity.

RESULTS

The search resulted in 15 studies that underwent qualitative testing, all were selected for quantitative analysis. The papers included: the mesiodistal of the upper first molar, lower first molar, and upper second molar, and the buccolingual of the upper first molar and upper second molar. The results showed that sensitivity and specificity rates were lower with the mesiodistal diameter, with rates of 0.577 for the lower first molar, 0.674 for the upper first molar, and 0.698 for the upper second molar, while the rates were higher with the buccolingual diameter, with 0.724 for the upper first molar, and 0.743 for the upper second molar. The power to estimate sex is greater for males than for females. High heterogeneity was detected among the studies of almost all dimensions, except sensibility for the lower first molar and specificity for the upper second molar.

CONCLUSIONS

None of the dimensions reached an accuracy of ≥80%, however, so they are not a reliable method for sex estimation in forensic practice.

Application of odontometric dimensions of molars in sex assessment in Bulgarians

INTRODUCTION

Sex estimation is an important step in developing a biological profile. Teeth are one of the most durable physical elements in the human body and thus can be used very successfully for this purpose. The aim of the present study was to determine sex differences in odontometric dimensions of maxillary and mandibular molars in Bulgarians.

Data on morphometric analysis of anterior teeth from Hazaribag College of Dental Sciences and Hospital,jharkhand

It is of interest to document data on morphometric (measurement of external form) analysis of maxillary and mandibular anterior teeth collected from a dental set up using mesio-distal (MD) dimension. The mesiodistal dimensions of all permanent anterior teeth (central incisor, lateral incisor and canine) of 25 males and 25 females patients were recorded using digital vernier calipers. Data were charted and statistical analysis was done using Mann Whitney U test. Data shows sexual dimorphism for every tooth between males and females. However, dimorphism was exhibited only in maxillary and mandibular canine, mandibular central incisors, and lateral incisor. Hence,odontometric parameters offer simple, reliable and cost-effective in forensic investigation for recording gender discrimination.

Odontometric sex discrimination in young Urhobo adults of South-South Nigeria

The spate of unidentified human remains as a result of kidnapping, killings, and so forth was the reason for this study. The purpose of this study was to measure the crown and cusps of each of the permanent maxillary first two molars to determine discriminant score and functions among Urhobo people of Nigeria. All Undergraduates of the Delta State University, Abraka, who are pure breeds Urhobo, form the study population. Three hundred and six subjects (171 males and 135 females), with mean age 22.88±3.34 years, participated in the study, which is based on the simple random sampling technique. All four crown widths and the four cusps of the maxillary first two molars were measured in millimeter, from a prepared study models of dental stone, and crown area, crown and cusps indices were calculated. The level of sexual dimorphism was also calculated for each parameter. Descriptive statistics was used to summarize the data while inferential statistics were used to ascertain significant sexual differences and to determine discriminant scores and functions. Statistical significance was fixed at P≤0.05. Crown and cusp dimensions of the first two permanent maxillary molars exhibited statistically significant sexual dimorphism. The highest percentage of sexual dimorphism was crown area of maxillary second molar (9.08%), followed by first molar (7.85%). Next, were metacone, paracone, disto-buccomesio-lingual, and mesio-buccodisto-lingual widths. The overall sex discriminatory precisions of the various parameters in the maxillary first two molars are good. The findings of this study are of relevance in forensic anthropology.

Volumetric assessment of the dental crown for sex estimation by means of cone-beam computed tomography

Sex estimation has a vital role in the solution of forensic cases when the identification of a large number of victims is needed. Considering the sexual dimorphism of the human teeth, the objective of this study was to estimate human sex by means of cone beam computed tomography (CBCT)-based volumetric assessment of the dental crown. A total of 78 CBCT images of the upper central incisors, upper and lower canines, and lower lateral incisors were equally selected from a Brazilian population aged between 8 and 36 years old. The dental crowns were subjected to image-based volumetric assessment by manual segmentation using the 3D slicer software, and the outcomes were compared by the Mann-Whitney test, unpaired t-test, Pearson correlation test, conditional backward stepwise logistic regression and intraclass correlation coefficient (α=0.05). The volumetric accuracy of the upper central incisor, upper canine and lower canine for sex estimation were 64.1%, 74.4% and 79.5%, respectively. The combined analysis of the upper and lower canines allowed an average accuracy of 83.7%. In conclusion, the combined volumetric analysis of the crown of the upper and lower canines can be applied for sex estimation in the studied population.

Employing Dimensional Disparity of Teeth to Establish the Gender in Odisha Population: A Dimorphic Study

Aims and Objectives:

Determination of sex is one of the most important and crucial steps in forensic science. Sexual dimorphism using odontometric analysis is found to vary in different populations making it necessary to attain values of a specific population which helps the identification possible. This present study attempts to establish sexual dimorphism using odontometric analysis in Odisha population.

Materials and Methods:

A total of 200 subjects (100 male and 100 female) between ages 18 and 25 years were included in the study. Intraoral Mesiodistal (MD) and Buccolingual (BL) dimensions of 28 teeth (maxillary and mandibular) excluding third molar were taken using digital Vernier calipers. Data were charted and decrypted and statistical analysis was done using SPSS Software version 20.

Results:

Our study showed larger dimensions of tooth in males when compared to females (maxillary right and left central incisor, 1^st and 2^nd molar). Interestingly, reverse dimorphism was also observed in few teeth.

Conclusion:

The results of the present study showed that the linear (MD and BL) dimensions of teeth played a major role in the determination of gender in individuals. The variations or reverse dimorphism could be a result of geographic variations.

Palatoscopy and odontometrics for sex identification and hereditary pattern analysis in a Navi Mumbai population: A cross-sectional study

Background:

Identification of an individual is a challenging task in the field of forensic odontology. Sometimes, the identity of individuals by fingerprints is difficult; hence, the examination of palatal rugae and the human dentition is a viable option.

Aims and Objectives:

The objective of the present study was to determine the sex of an individual and the hereditary pattern using three parameters are as follows: palatine rugae, dimensions of maxillary molar and maxillary canine.

Materials and Methods:

A cross-sectional study involved a total of 200 participants which included 60 males, 60 females and 20 families with four members each. Maxillary impressions were made with elastomeric impression material, and dental stone was used to make the models. The parameters used were as follows: palatine rugae classified by Thomas and Kotze (1983), which included the shape, size, direction and unification pattern, mesiodistal (MD) width of canines and intercanine width and MD and buccolingual width of maxillary molars.

Statistical Analysis:

Unpaired t-test and the median test were used to assess the sex differences in the number and unification pattern for the palatal rugae and to compare dimensions measured for males and females for the odontometric data. The data collected was statistically analyzed using the Statistical Package for Social Sciences 17.0 statistical program for windows. The statistical significance was fixed at 0.05.

Results:

Males showed more number of converging rugae and females showed more number of diverging patterns of rugae. The number of primary and forward rugae was more in both the genders and females showed more wavy rugae while males showed more number of straight and curved rugae. The maxillary canine and maxillary molar dimensions both were more in males than the females and also none of these parameters showed a hereditary pattern.

Conclusion:

Rugae pattern and the human dentition are both highly individualistic and can be used for personal identification and sex determination.

Sexual dimorphism of enamel area, coronal dentin area, bicervical diameter and dentinoenamel junction scallop area in longitudinal ground section

Introduction:

Sex determination plays an important role in forensics; several studies done using radiographs, model cast and animal teeth have shown that males possess larger tooth crown and more dentin than that of the females. As physical sectioning of tooth provides more accurate measurement of enamel thickness when compared with other methods, the present study was done to evaluate and compare enamel area (EA), coronal dentin area (CDA), bi-cervical diameter (BCD), average enamel thickness (AET) and dentinoenamel junction scallop area (DEJ-SA) in longitudinal ground sections of first premolars between males and females.

Materials and Methods:

A total of 60 extracted first premolar teeth were used for the study, of which 30 were from male and 30 were from female. A longitudinal ground section of 15 maxillary and 15 mandibular premolars of approximately 50 μm was prepared buccolingually at the center of each tooth and mounted on the slide. Multiple photomicrographs were captured with the help of Image Analysis System Software-Progres, Speed XT core 3. EA, CDA, length of the dentinoenamel junction and BCD were measured. Average DEJ-SA and AET were also calculated.

Results:

Mann–Whitney U- test was used for statistical analysis. It was found that EA and AET were significantly greater in females than in males. On the contrary, it was found that CDA was significantly greater in males than in females. However, no significant difference was found in BCD and DEJ-SA between males and females.

Conclusion:

Permanent first premolar can be reliably used in the field of forensic in establishing gender of individuals by measuring its EA, CDA and AET.

Determination of sex on the basis of hyoid bone measurements in a Japanese population using multidetector computed tomography

Sex determination for unidentified human remains is important because the determined sex is usually used as a foundation for the estimation of other biological profiles. This study investigated the sexual dimorphism of the adult hyoid bone and developed discriminant equations to accurately estimate sex in a contemporary Japanese population using measurements on two-dimensional computed tomography (CT) images. The study sample comprised 280 cadavers (140 males, 140 females) of known age and sex that underwent postmortem CT and subsequent forensic autopsy. In accordance with previous studies, seven measurements were performed using two-dimensional CT reconstructed images. Most measurements of males were significantly greater than those of females. The perpendicular length from the most anterior edge of the hyoid body to the line that connects the most distal points of the greater horns of the hyoid and the linear distance between the most lateral edges of the hyoid body most significantly contributed to sex determination. This study demonstrated that discriminant functions on the basis of three measurements provided higher rates of accurate sex classification (93.3-94.6%) than univariate functions. Therefore, the hyoid bone is highly sexually dimorphic in the contemporary Japanese population and may be useful in forensic contexts for sex determination with a high level of accuracy.

Sex determination using humeral dimensions in a sample from KwaZulu-Natal: an osteometric study

The morphological characteristics of the humeral bone has been investigated in recent times with studies showing varying degrees of sexual dimorphism. Osteologists and forensic scientists have shown that sex determination methods based on skeletal measurements are population specific, and these population-specific variations are present in many body dimensions. The present study aims to establish sex identification using osteometric standards for the humerus in a contemporary KwaZulu-Natal population. A total of 11 parameters were measured in a sample of n=211 humeri (males, 113; females, 98) from the osteological collection in the Discipline of Clinical Anatomy, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa. The difference in means for nearly all variables were found to be significantly higher in males compared to females (P<0.01) with the most effective single parameter for predicting sex being the vertical head diameter having an accuracy of 82.5%. Stepwise discriminant analysis increased the overall accuracy rate to 87.7% when all measurements were jointly applied. We conclude that the humerus is an important bone which can be reliably used for sex determination based on standard metric methods despite minor tribal or ancestral differences amongst an otherwise homogenous population.

Morphometric significance of maxillary arch in sexual dimorphism in North Indian population

BACKGROUND

Tooth is the hardest and chemically (except mineral contents) the most stable structure in the body, which makes teeth as the first-rate material for genetic and forensic investigations. Sex determination of skeletal remains forms an important part of archaeological and medicolegal examinations. Hence, the aim of the present study was to analyse the morphometric and dimensional variation between male and female in north Indian population using maxillary arch parameters.

MATERIALS AND METHODS

Fifty male and fifty female patients of age group 18-35 years were randomly selected after taking detail history. All maxillary impressions were made with alginate and poured in type III dental stone. These casts were measured for maxillary inter-canine width, maxillary first inter-premolar width, anteroposterior palatal width and palatal depth using a digital vernier caliper and findings were correlated with sexual dimorphism.

RESULTS

The maxillary inter-canine width, maxillary first inter-premolar width, and palatal depth showed a significant difference with P < 0.05 between the means of two populations. Anteroposterior palatal width showed the comparatively less significant difference between two populations.

CONCLUSION

Among north Indian population, maxillary inter-canine width, maxillary first inter-premolar width, and palatal depth can be used for sex assessment. The anteroposterior palatal width parameter is comparatively less significant in sex determination.

Comparative assessment of maxillary canine index and maxillary first molar dimensions for sex determination in forensic odontology

Background:

Sexual identification of immature skeletal remains is still a difficult problem to solve in forensic anthropology. In such situations, the odontometric features of the teeth can be of immense help. Teeth, being the hardest and chemically the most stable tissue in the body, are an excellent material in living and nonliving populations for anthropological, genetic, odontologic, and forensic investigations. Using tooth size standards, whenever it is possible to predict the sex, identification is made easier because then only missing persons of one sex need to be considered.

Aim:

To determine sex from the odontometric data using maxillary canine index and maxillary first molar dimensions and to determine which index gives higher accuracy rate for sex determination using only maxillary cast.

Materials and Methods:

In a sample size of 200 population (100 male and 100 female), alginate impression was taken of maxillary arch and poured with dental stone. Using Vernier caliper, the dimension of maxillary first molar (buccolingual [BL] and mesiodistal [MD]), canine (MD), and intercanine distance was measured on the cast. The obtained data were analyzed using discriminant statistical analysis.

Result and Conclusion:

This study concludes that BL dimension of maxillary first molar is a more reliable indicator for gender determination than other molar and canine dimensions in maxilla.

Diagonal tooth measurements in sex assessment: A study on North Indian population

Background:

Sexual dimorphism has been of great interest to anthropologists and odontologists. Dental measurements are important in anthropology for the study of sexual dimorphism with most common being the traditional linear odontometric measurements. Apart from these, alternative dental measurements have been developed such as the crown and cervical diagonal diameters and mesiodistal and buccolingual cervical diameters of teeth.

Aims and Objective:

The primary objective of the following study is to assess the degree of sexual dimorphism in teeth of a North Indian population using the crown diagonal diameters and secondary is to evaluate the applicability of diagonal measurements in sex determination by means of discriminant functional analysis.

Materials and Methods:

The study sample comprised 200 individuals (100 males and 100 females) of an age group ranging from 18 to 57 years, in a North Indian population. The mesiobuccal-distolingual (MBDL) and distobuccal-mesiolingual (DBML) crown diameters of seven maxillary and seven mandibular teeth on the study models were measured using digital Vernier calipers.

Results:

The most dimorphic teeth amongst all for crown diagonal diameters are the maxillary central incisors and the least dimorphic are the maxillary second premolars. The mean diagonal crown dimensions in all but one tooth (DBML of maxillary lateral incisor) of males exceeded that of females. The difference was statistically significant in MBDL dimensions of maxillary and mandibular central incisor, canine, first and second molar and DBML dimensions of maxillary central incisor and maxillary and mandibular canine, first molar and second molar (P < 0.05). The accuracy of determination of sex by MBDL crown dimension ranges from 55% to 75% in males and 47-84% in females, while by DBML crown dimension ranges from 55% to 80% in males and 65-80% in females with the overall accuracy of sex determination ranging from 51% to 80% respectively.

Conclusion:

MBDL and DBML crown dimensions are reliable indicators and can be used along with or/and instead of linear measurements in sex determination. In situations in which it is difficult to take correct measurements of linear dimensions of teeth, these alternative odontometric measurements can be used consistently to determine sex.