|Year : 2019 | Volume
| Issue : 2 | Page : 68-72
Establishment of sexual dimorphism using maxillary canine of the university of maiduguri students, Nigeria
Saleh Nuhu1, Babagana Mohammed Dalori2, Lawan Hassan Adamu3, Mohammed Alhaji Buba4
1 Department of Human Anatomy, Faculty of Basic Medical Sciences, Yusuf Maitama Sule University, Kano State, Nigeria
2 Department of Human Anatomy, College of Medical Sciences, University of Maiduguri, Maiduguri, Borno State, Nigeria
3 Department of Anatomy, Faculty of Basic Medical Sciences, Bayero University, Kano State, Nigeria
4 Department of Human Anatomy, Faculty of Basic Medical Sciences, Yusuf Maitama Sule University,Kano State, Nigeria
|Date of Submission||17-May-2019|
|Date of Acceptance||22-Jul-2019|
|Date of Web Publication||26-Dec-2019|
Mr. Saleh Nuhu
Department of Human Anatomy, Faculty of Basic Medical Sciences, Yusuf Maitama Sule University,Kano State
Source of Support: None, Conflict of Interest: None
Background: Sex determination is one of the key tools used by forensic odontologists for identification of mass disaster victims. Teeth are the hardest structure in the body that will resist biological, chemical, and mechanical degradation for a considerable period of time.
Aims: This study was aimed at establishing sexual dimorphism in maxillary canine tooth parameters among the Northeastern Nigerian population in the University of Maiduguri and to compare the percentage of sexual dimorphism with ethnic populations.
Materials and Methods: The study was conducted on 208 students consisting of 102 males and 106 females of the University of Maiduguri, Borno State, Nigeria. The measurements of the greatest mesiodistal (MD) width of the maxillary canine and the intercanine distance were done using the Vernier caliper with a resolution of 0.02 mm and a divider with a fixing device.
Results: It was observed that in all the maxillary parameters considered, males tend to have statistically significant higher mean value compared to the female counterpart. Left maxillary canine width exhibited a higher percentage of sexual dimorphism among the parameters measured.
Conclusion: The MD and intercanine distance in maxillary canine were sexually dimorphic among the students of the University of Maiduguri, Northeastern Nigeria.
Keywords: Maxillary canine, Nigeria, sexual dimorphism
|How to cite this article:|
Nuhu S, Dalori BM, Adamu LH, Buba MA. Establishment of sexual dimorphism using maxillary canine of the university of maiduguri students, Nigeria. Int J Forensic Odontol 2019;4:68-72
|How to cite this URL:|
Nuhu S, Dalori BM, Adamu LH, Buba MA. Establishment of sexual dimorphism using maxillary canine of the university of maiduguri students, Nigeria. Int J Forensic Odontol [serial online] 2019 [cited 2020 Jul 2];4:68-72. Available from: http://www.ijofo.org/text.asp?2019/4/2/68/274043
| Introduction|| |
The identification of sex plays an important role in mass fatality incidents where bodies are damaged beyond recognition, especially in situ ations where only fragments of jaw bones with teeth are found. In this situation, sex determination may be possible using teeth., Although the morphology of the tooth structure is similar in males and females, the size of the tooth does not necessarily remain the same, as the tooth size is determined by cultural, environmental, racial, and genetic factors.
Since teeth are one of the strongest tissues in the human body and are known to resist postmortem changes, they serve as good predictors of sex when other preferred predictors such as the pelvis or long bones are destroyed or fragmented. They are also useful in reconstructive identification and it is possible to obtain reasonable quantities of information concerning race, stature, and age from their measurements.
Sexual dimorphism refers to the systemic differences in size and appearance between individuals of different sexes in the same species., Varying degree of sexual dimorphism in human dentition has been shown in many studies.,,, Ditch and Rose were among the first to prove that teeth dimensions can be successfully used in determining sex in poorly preserved and fragmentary skeletal remains.
In many studies on the contemporary human population, it has been shown that tooth crowns are larger in males than in females possibly due to a longer period of amelogenesis for both deciduous and permanent teeth in males., Slow maturation in males was shown to be due to their Y sex chromosome. It has also been suggested that chromosomes responsible for the sexual difference are in direct connection to growth and development of teeth.
Linear dimensions are considered to be simple, reliable, and inexpensive in a community where the latest technology (DNA fingerprinting methods) is not available and sex has to be determined from jaw fragments. Therefore, this study was aimed at evaluating the sexual dimorphism in permanent maxillary canines among the students of the University of Maiduguri in Borno State, Nigeria.
| Materials and Methods|| |
Study location and participants
This study was conducted on 208 students consisting of 102 males and 106 females of the University of Maiduguri, Borno State, Nigeria. The measurements of the greatest mesiodistal (MD) width of the maxillary canine and the intercanine width were done using the Vernier caliper (a) with a resolution of 0.02 mm and a divider with a fixing device (b) [Figure 1].
The study population comprised of 208 student (males 102 and 106 females) participants randomly selected from the student population of the University of Maiduguri, Nigeria, using simple lottery method. The Cochran standard formula was used in determining the sample size. Sample size of 138 was obtained but increased to 208 to increase the power of statistics. The age group of the participants was 17–35 years. This group was selected, as attrition is minimal in this age group.
Inclusion and exclusion criteria
The subjects having a complete set of fully erupted, morphologically well-formed, periodontally healthy, noncarious, nonattrition, nonhypoplastic teeth and satisfactorily aligned maxillary teeth who willingly consented were included in the study. Individuals with carious, restored, hypoplastic teeth, teeth with prosthesis, malocclusion, and mobile teeth were excluded from the study.
Collection of biodata
A brief questionnaire was completed for all participants, with age, measurement of their MD width of their mandibular canine, and mandibular intercanine distance.
The Vernier caliper and divider were disinfected with Dettol (Reckitt Benckiser, Nigeria) before being used in another person.
Determination of maxillary canine parameters
Maxillary canine widths
After obtaining the consent of the students, the maximum MD dimensions of the two permanent maxillary canines (left and right maxillary canine) were measured between the anatomic contact points directly on the subject, using a sliding Vernier caliper held parallel to the occlusal plane. In a situation where the placement of the sliding Vernier caliper was found to be difficult, a manual divider with very fine tips was used. Later, the divider distance was measured with the Vernier caliper [Figure 2].
Maxillary intercanine distance
It was measured as the linear distance between the tips of the right and left maxillary (MxCW) canines [Figure 3].
Maxillary canine index
The formula used to calculate the maxillary canine index (MxCI) was adapted from that used by Rao et al. and Shastry et al.
Percentage of sexual dimorphism and statistical analyses
The percentage of sexual dimorphism was calculated using the formula given by Garn et al.
where Xm– mean value of males, Xf– mean value of females Data were expressed as mean ± standard deviation. One-way ANOVA was used to determine the sexual dimorphism. The determination of sex was based on the MD width, intercanine distance, observed maxillary canine index, and the standard maxillary canine index. If the observed canine index was more than the standard canine index, the individual was considered to be male, and if the observed canine index was less than the standard canine index, the individual was considered to be female. Data were analyzed statistically using SPSS version 20 (IBM Corp., Armonk, NY, USA). P < 0.05 was set as the level of significance.
| Results|| |
The mean mediodistal width of maxillary canine for the left (male = 8.50 ± 0.60 mm and female = 7.90 ± 0.70 mm) and right (male = 8.40 ± 0.80 mm and female = 8.00 ± 0.50 mm) sides was significantly higher among males than females (P = 0.0001 and P = 0.0001 for the right and left maxillary canines, respectively). A similar observation was also found for intercanine distance, with a significantly higher mean values for males (37.00 ± 2.60 mm) than females (36.10 ± 2.60 mm) (P = 0.001) as shown in [Table 1].
|Table 1: ANOVA test for sexual dimorphism in maxillary canine parameters|
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[Table 2] shows the mean maxillary canine index (MxCI) of the right (male = 0.23 ± 0.022 and female = 0.22 ± 0.017) and left (male = 0.23 ± 0.02 and female = 0.22 ± 0.02) sides, with less statistically significant difference between the two genders for the left and right sides (P = 0.002 and 0.047, respectively).
The percentage of sexual dimorphism in the left and right mediodistal width of maxillary canines was 7.59% and 5.00%, respectively, while for the intercanine distance, it was found to be the least (2.49%), whereas the sexual dimorphic percentage for both left and right canine indexes was 4.55%. The sexual dimorphism among the left MD width (7.59%) and the right MD width (5.00%) in the present study was shown to be higher in the left maxillary canine than the right maxillary canine, indicating their significance in sex determination [Table 3].
| Discussion|| |
Many researches have been conducted on the measurements of the crown of teeth between males and females and reported certain differences. Although morphologically similar to male and female, the size of the teeth may not remain the same, as it is determined by various factors such as exercise, racial genetic factors, cultural, and metabolic activities. Measurements of tooth dimensions are quick, less time consuming, and noninvasive and can be easily performed compared to DNA and other forensic techniques.
Intercanine distance and canine index are useful parameters in differentiating sexes as the eruption of canines and growth in width of both the jaws, including the width of the dental arches, are completed before the adolescent growth changes and the intercanine distance do not increase after 12 years of age.
The dimensions of canine teeth have been studied by several methods such as Moiré topography and Fourier analysis and measurement of linear dimensions such as MD width, buccolingual width, and incisocervical height.,,,, The limitation of some of the aforementioned methods to small samples as opposed to measurements of dimensions of canine teeth makes it simple, reliable, inexpensive, and easy to perform on a large population.
In this study, it was found that males in Maiduguri, Northeastern Nigeria, have higher left MD width than their female counterparts. This is in agreement with that of Zirahei et al. who conducted a study on 231 students of Kogi State Polytechnic, North Central Nigeria, where they found a statistically significant difference between males and females in their MD width with the males having a higher mean value in both sides (left and right). This greater dimension of MD width of canines in males can be attributed to the Y-chromosome, which is responsible for the thickness of dentin, contributing to the width of a tooth., However, the mean MD width for this study was higher than the one reported by Zirahei et al. This may be due to the different environmental locations of the study area and their eating habit.
Similarly, Yuwanati et al. conducted a study on the Central Indian population where they found the mean MD width of the left maxillary canine to be statistically higher in males than females. Although the mean value for the present study was higher, this may be a result of racial difference that exists between MD width in races.
In contrast to the present study, Mohammed et al. in their study on the Saudi Arabian population found a statistically nonsignificant difference in the mean MD width of maxillary canines of males and females of the population (54 ± 0.68 mm [right] and 7.54 ± 0.67 mm [left] in males, and 6.8 ± 0.925 mm [right] and 6.83 ± 0.934 mm [left] in females)[Table 4].
|Table 4: Comparison of the present study with previous studies in some regions|
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In this study, statistically significant sexual dimorphism was exhibited by the maxillary left canine (7.59%) and the maxillary right canine (5.00%). This finding is in accordance with other previous studies.,,,,
| Conclusion|| |
This study has established sexual dimorphism in maxillary canine teeth, which is an important adjunct in sex determination in the University of Maiduguri students, Northeastern Nigeria. Central Indian population has the closest value as compared to the finding of the present study, followed by the population of the North Central Nigeria.
We thank all those who volunteered to participate in this research and those that help in one way or the other in the data collection process.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]