|Year : 2016 | Volume
| Issue : 4 | Page : 386-390
Use of mandibular canine index as a tool in gender dimorphism: A phenotypic study
Taseer Bashir1, Srinivas Kandakurti1, Jyoti Gupta1, Arti S Sachdeva1, Naeem Ahmad2, Vijay Krishnan1
1 Department of Oral Medicine Diagnosis and Radiology, Career Post-Graduate Institute of Dental Sciences, Lucknow, Uttar Pradesh, India
2 Department of Prosthodontics, Career Post-Graduate Institute of Dental Sciences, Lucknow, Uttar Pradesh, India
|Date of Submission||23-Nov-2015|
|Date of Acceptance||23-Dec-2016|
|Date of Web Publication||21-Feb-2017|
Dr. Taseer Bashir
Department of Oral Medicine Diagnosis and Radiology, Career Post-Graduate Institute of Dental Sciences, Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: The role of human dentition in gender dimorphism can be investigated owing to its resistance against peri and postmortem insults. Hence, it forms an excellent tool for forensic, genetic, odontological and anthropological investigations. Among all the teeth, the mandibular canines are found to exhibit the greatest gender dimorphism. Aim: To determine a method of diagnosing gender from the dentition in a population of Ghailla village, Lucknow, Uttar Pradesh, India. Materials and Methods: Intercanine distance and widths of both right and left mandibular canine were measured intraorally and on the dental casts of the same individuals followed by mandibular canine index calculation. Results: In the female group, the mesiodistal (MD) width was less than 7 mm in the majority of individuals. It was also interpreted that the left canine was found to exhibit greater gender dimorphism. The reliability with regards to gender was 76.6% for males and 73.3% for females. The standard value of mandibular canine index was (0.35); hence, numerical quantities above this value belonged to the masculine sex and below this value belonged to the feminine sex. Conclusion: The left canine was found to exhibit greater gender dimorphism. Whenever the width of either canine was greater than 7 mm, the probability of gender being male was 100% in the present study.
Keywords: Canine index, canine width, intercanine distance, mandibular canines
|How to cite this article:|
Bashir T, Kandakurti S, Gupta J, Sachdeva AS, Ahmad N, Krishnan V. Use of mandibular canine index as a tool in gender dimorphism: A phenotypic study. J Indian Acad Oral Med Radiol 2016;28:386-90
|How to cite this URL:|
Bashir T, Kandakurti S, Gupta J, Sachdeva AS, Ahmad N, Krishnan V. Use of mandibular canine index as a tool in gender dimorphism: A phenotypic study. J Indian Acad Oral Med Radiol [serial online] 2016 [cited 2021 Jan 28];28:386-90. Available from: https://www.jiaomr.in/text.asp?2016/28/4/386/200633
| Introduction|| |
Gender dimorphism refers to the differences in the size and form between males and females that can be applied for dental identification. These differences can be applied as no two mouths are similar. Gender determination is the first and foremost task in any kind of forensic investigation of unidentified bodies and skeletal remains. As the total human population is more or less equally divided among both the genders, it also reduces the search of individuals to half.It is a known fact that enamel is the hardest known substance in the human body. Teeth are made of enamel and hence are supposed to bear any kind of trauma. The human teeth owing to its extreme hardness value and high level of resistance against any kind of decomposition are selected for postmortem investigations. It has been reported in previous studies that human teeth possess some kind of dimorphic variations. Hence, this feature must be explored further because it may be used for gender determination in adjunct with odontometric analysis.
Canines are known as “cornerstone teeth” due to their size and the highest survival rate. It has a mean eruptive age of 10.87 years. Canines are the least encountered teeth for extraction as well as the least involved tooth by periodontal disease. Hence, for gender identification, mandibular canines are selected among all the teeth.
| Aim|| |
To measure the gender dimorphism using mandibular canine index in a Ghailla population.
| Objectives|| |
- To measure the mesiodistal (MD) crown width of mandibular canine
- To measure the mandibular canine arch width or intercanine (IC) distance
- To determine a method for diagnosing gender from the dentition in a population of Ghailla village, Lucknow, Uttar Pradesh, India.
| Materials and Methods|| |
This study was performed among apparently healthy individuals reporting to the Department of Oral Medicine Diagnosis and Radiology (OMDR) wing in the Career Post-Graduate Institute of Dental Sciences (CPGIDS), Lucknow. The samples consisted of mandibular dental arches from 60 patients consisting of 30 males and 30 females, aged between 20 and 30 years. This age group was selected because attrition is minimal in this age group. Selection criteria included a complete set of fully erupted healthy teeth.
After obtaining a written informed consent, the impressions of the teeth were made using plastic trays  and irreversible hydrocolloid impression material and were immediately poured in type-III dental stone [Figure 1]. MD dimensions  of both the mandibular canines in the individual/cast were measured with a divider  which was positioned perpendicularly along the long axis of the selected tooth or coinciding with it [Figure 2] and [Figure 3]. The IC distance was measured between the cusp tips of mandibular canines using a divider positioned perpendicular to the long axis of the teeth [Figure 4].
|Figure 2: Measurement of the left mandibular canine mesiodistal width in the participant|
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|Figure 3: Measurement of the left mandibular canine mesiodistal width in the cast|
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Percentage of dimorphism
It is defined as “the percentage by which the tooth size of male gender exceeds that of the female gender.” All the observations and calculations were done by a single investigator to eliminate the incidence of interobserver error. Each reading was also recorded three times, and its average was obtained to minimize intraobserver error. The data collected was statistically analyzed.
Mandibular canine index
Ratio of MD crown width of mandibular canine to mandibular canine arch width or IC distance using the formula given by Rao et al.(1989) was measured.
Gender dimorphism in the right and left mandibular canines was calculated using the formula given by Garn and Lens (1967):
Percentage of gender dimorphism = (Xm/Xf) −1 × 100
Xm = Mean value of males
Xf = Mean value for females
The sample was evaluated using the Statistical Package for the Social Sciences version 8.3.3 software (SPSS Inc., Chicago, IL, USA). It was inferred that a definite statistically significant gender dimorphism existed in mandibular canines within Ghailla village population.
Selection of participants
After consulting our statistician, the sample size was calculated with 1% of the total population reporting to the dental clinic in a year, which is approximately 250 patients per month. This implies that 30 individuals [1% of 3000 individuals (250 × 12)] are sufficient to make calculations regarding gender dimorphism in this population to have a good power of analysis.
A purposive sample of 30 individuals in each group presenting to this dental college cum tertiary care hospital was selected for this study.
| Results|| |
The statistical analysis showed that 23 males (out of 30) and 22 females (out of 30) were correctly classified (success rate of 74.9%). [Table 1] shows the statistical significance of different parameters. [Table 2] shows that, in the female group, MD width was less than 7 mm in a majority of participants. [Table 3] shows that the left canine exhibited greater gender dimorphism whether measurements were made intraorally or on casts. The reliability with regards to gender was 76.6% for males and 73.3% for females. Standard value of mandibular canine index was (0.35) numerical quantities; values above this belonged to the masculine sex and below this belonged to the feminine sex.
|Table 2: Range of canine width in different groups of males versus females|
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| Discussion|| |
Studies on tooth morphology have been conducted in the past using either intraoral measurements or measurements on casts. Barrett et al. observed that the reliability of intraoral measurements were less. Garn and Lewis, and Lysell and Myrberg  found that the mandibular canines exhibited the greatest gender dimorphism among all the teeth. The mean eruptive age of mandibular canines is approximately 10.87 years. It is already reported that canines are the least affected teeth by the periodontal disease compared to others. These are also the last remaining teeth in the oral cavity. Because enamel is the hardest known part of human body and canines possess the maximum amount of it, they are the most resistive to any kind of trauma. In the present study, participants in the age group of 20–30 years were included, as early adulthood dentition has less mutilation and less attrition, which is in agreement with the findings of Doris et al. Nair et al. concluded that the left mandibular canine revealed maximum sexual dimorphism (7.7%), followed by the right mandibular canine (6.2%). Similarly, Kaushal et al. also found left mandibular canine (9.26% in casts and 8.89% intraorally) to be more dimorphic than the right mandibular canine (7.45% in casts and 7.44% intraorally). In the present study, similar findings were obtained but with a higher value (9.79% for the left mandibular canine, followed by the right mandibular canine with 7.96%).
However, in 1993, Hashim and Murshid  found that there was no significant difference between the left and right mandibular canines in a Saudi population sample. On the contrary, Vishwakarma and Guha  found that the right mandibular canine (12.51%) was more dimorphic than the left mandibular canine (10.15%). Hence, this difference can be attributed to several factors such as racial, environmental, cultural and nutritional factors. Variation in food source is a known environmental factor that causes morphological alterations in tooth. Hence, this area of research demands further investigation and emphasizes on the need for population-specific data.
| Conclusion|| |
Despite certain limitations of the study, it was concluded that the left canine exhibited greater gender dimorphism. Whenever the width of either canine was greater than 7 mm, probability of the gender being male was 100% in the present study. This finding has great medicolegal significance, especially for identification of gender. Odontometric parameters can be used for determining gender in a large population because they are simple, inexpensive and easy to measure. However, it should always be contemplated as an appendage rather than as a primary option.
The authors acknowledge the Department of Prosthodontics, Career Post-Graduate Institute of Dental Sciences, Lucknow, Uttar Pradesh, India, for the help rendered in conducting this study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3]