European Journal of Cardiovascular Medicine

One of the main processes in forensic identification is sex determination. Since teeth are the strongest and most resilient tissues in the human body, they are useful in forensic examination because they do not deteriorate after death. Because of its physical robustness in men, the mandibular canine has continuously demonstrated considerable sexual dimorphism among a variety of odontometric parameters [1].

The ratio of the mandibular canine's mesiodistal width to the inter-canine distance is used to compute the Mandibular Canine Index (MCI), which was first proposed by Rao et al. (1989). When skeletal or soft tissue characteristics are not accessible, this index acts as a differentiating factor to determine sex.

This study is to investigate the reliability of MCI as a forensic technique for gender detection and evaluate sexual dimorphism in mandibular canines among a young group aged 18 to 25.

Since sexual dimorphism is essential to identifying an individual, forensic anthropologists are concerned about it. For anthropological, genetic, odontologic, and forensic investigations, teeth are the most durable and indestructible portion of the body in both living and non-living populations [2].

Additionally, teeth exhibit the least amount of natural structure turnover and can be recognized even in cases when the rest of the body has been disfigured or decomposed; this is particularly true for identification on partial adult skeletons [3]. In the event of a big disaster, where bodies are frequently irreparably disfigured, sex identification is crucial [4].

Since no two mouths are alike, sexual dimorphism refers to the variations in size, stature, and appearance between males and females that can be used to identify teeth. Since teeth can be easily examined and no two have the same morphology, they make a great forensic tool for determining a person's sex. Canines are the teeth in the human dentition that are least susceptible to periodontal disease, heavy occlusal loading, brushing abrasion, calculus, and plaque. Because of their longevity in the mouth cavity, canines are the best teeth to research [5]. In forensic investigations, mandibular canines—which have an average eruption age of 10.87 years—are regarded as the "key teeth" for identifying victims, both living and deceased. Of all the teeth in the human dentition, mandibular canines are shown to have the highest degree of sexual dimorphism [6-7].

The current study set out to investigate how accurately gender might be distinguished using the mandibular canine index.

Analysis of Gaps

In order to determine gender, a thorough examination of the mandibular canine index is required. to develop a quick, easy, affordable, and non-invasive way to assess sexual dimorphism. Cut-off value In the Indian population, the mandibular canine index is not well-established. Forensic identification, anthropological study, and restorative and surgical dental procedures will all benefit from this area, which is still understudied in the youth population.

A cross-sectional study was conducted in a dental college setting among 100 healthy individuals (50 males and 50 females) aged 18–25 years. Individuals with intact, fully erupted mandibular canines and no history of orthodontic treatment, dental wear, or trauma were included.

Measurements

·         Mesiodistal width of right and left mandibular canines was measured between the contact points using a digital vernier caliper (accuracy 0.01 mm).

·         Inter-canine distance was measured between cusp tips of the right and left mandibular canines.

·         Each measurement was recorded thrice and averaged for accuracy.

Mandibular Canine Index (MCI)

MCI=Mesiodistal width of mandibular canineInter-canine distance\text{MCI} = \frac{\text{Mesiodistal width of mandibular canine}}{\text{Inter-canine distance}}MCI=Inter-canine distanceMesiodistal width of mandibular canine

Statistical Analysis

Mean and standard deviation were calculated. Differences between males and females were analyzed using the t-test. A discriminant function analysis was used to establish the cutoff MCI for gender prediction. Significance was set at p < 0.05.

Table 1: Distribution of Study Population

Table 2: Comparison of Mandibular Canine Width (mm)

                                                        *Statistically significant at p < 0.05

Table 3: Comparison of Inter-Canine Distance (mm)

Table 4: Comparison of Mandibular Canine Index (MCI)

Standard MCI (Cut-off): 0.262

• MCI > 0.262 → Male
• MCI < 0.262 → Female
  Accuracy: 80%

Significant sexual dimorphism in young adults' mandibular canine size was shown in this study. Mesiodistal widths and inter-canine distances were consistently greater in males than in females. These results support the validity of dogs as gender indicators and are in line with earlier research by Rao et al. (1989), Kaushal et al. (2003), and Sharma et al. (2016)[8]. Males had higher mean MCI values, suggesting that sex distinction is influenced by wider dental arches and greater tooth dimensions. Due to functional dominance during mastication, the right dog showed somewhat greater sexual dimorphism. The resulting threshold value (0.262) offered a prediction accuracy of 80% despite the fact that male and female values overlapped, indicating that MCI is a straightforward, affordable, and trustworthy technique for estimating gender in forensic instances when skeletal remains are not available.

Compared to the current study, the sex prediction rates of Reddy et al. [9] in a Northern Indian community were significantly higher at 82%. The regional variations in tooth size are the cause of these discrepancies. In a similar vein, investigations had a larger percentage of females who were accurately predicted than the current study. Studies on male sex prediction by Ahmed [10] in an Iraqi population were lower than the current study (57.50%) in an Indian community. It is conceivable to assume that evolutionary change, genetic factors, and ethnic background are the cause of the low accuracy.

The study also revealed a substantial difference in RMC values between males and girls. This is comparable to Ahmed's findings [11–12]. However, the results of the present study for mean mesiodistal of RMC and LMC for boys and females was lower Studies undertaken in many groups and nations have shown that there are little variances in the mesiodistal breadth of the mandibular canine, which may account for the racial variability in tooth size. Consequently, a number of differences as well as commonalities were found when the current data was evaluated and compared to earlier research.

Males showed significantly greater mandibular canine width and inter-canine distance than females. The Mandibular Canine Index exhibited significant sexual dimorphism (p < 0.001). The right canine demonstrated slightly higher accuracy for gender prediction. The overall accuracy of MCI in gender determination was 80%, indicating its usefulness as a forensic tool in young populations.

1.       Rao NG, Rao NN, Pai ML, Kotian MS. Mandibular canine index—a clue for establishing sex identity. Forensic Sci Int. 1989;42(3):249–254.

2.       Kaushal S, Patnaik VV, Agnihotri G. Mandibular canines in sex determination. J Anat Soc India. 2003;52(2):119–124.

3.       Sharma P, Sharma M, Wadhwan V. Sexual dimorphism in mandibular canines: A study in North Indian population. J Forensic Dent Sci. 2016;8(1):46–49.

4.       Acharya AB, Mainali S. Limitations of the mandibular canine index in sex assessment. J Forensic Leg Med.

5.       Whittaker DA. An introduction to forensic dentistry. Quintessence International, 1994; 25: 723-730 2.

6.       Lund and Mornstad Gender determination by odontometrics in a Swedish population, Journal of Forensic Odontostomatol 1999 Dec 17 (2): 30-4. 3.

7.       Muller M, Lupi‑Pegurier L, Quatrehomme G, Bolla M. Odontometrical method useful in determining gender and dental alignment. Forensic Sci Int., 2001; 121:194‑197.

8.       Kaushal, S, Patnaik VVG, Agnihotri G. Mandibular canines in sex determination. J Anat Soc India, 2003; 52: 119-124.

9.       Boaz K, Gupta C. Dimorphism in human maxillary and mandibular canines in establishment of gender. J Forensic Dent Sci., 2009; 1: 42-44

10.    Kapila R, Nagesh KS, R Iyengar A, Mehkri S. Sexual dimorphism in human mandibular canines: A radiomorphometric study in South Indian population. J Dent Res Dent Clin Dent Prospects, 2011; 5: 51‑54..

11.    Padmavati K, Farah VM, Syed AA, Ather SA. Mandibular canine index: A tool for sex determination. J Indian Dent Assoc., 2011; 5: 18. 8.

12.  Sunil Shrestha, Rojina Shakya, Dil Islam Mansoor, Dilip Kumar Mehta, Shamsher Shrestha. Estimation of sex using mandibular canine index in a young Nepalese population. An Integral Journal Of Experimental and Clinical Anatomy, 2019, Vol. 13, Issue 3, Page 23-27.