Mandibular Measurements for Sex and Age Estimation in Brazilian Sampling

Abstract

Objective: The present study aimed to evaluate the possibility of sex and age estimation in a Brazilian sample, using the following five mandibular measurements: coronoid height, gonial angle, bigonial distance, ramus height, maximum length.

Materials and methods: In total, 103 mandibles were measured, 53 female and 50 male, grouped according to the age in 5 different groups. Two different observers performed all these measurements. For statistical analysis, one-way ANOVA was used with a significance level of 5% to verify if the mandibular measurements were related to age. The Student t-test was used for comparisons between the sex samples. Eighty three samples were used to develop a logistic regression model. The intra-observer and inter-observer differences were evaluated using the Kappa coefficient.

Results: The sex differences were statistically significant in all the variables, and all of them were larger in men, apart from the variable related to the gonial angle (GA), which was larger in women. For the logistic regression formula, the variables used were: bigonial distance and mandibular ramus, with 90% accuracy. For age, the measurements did not show a pattern. The inter and intra-observer values were greater than 0.85.

Conclusion: In conclusion, it is possible to estimate sex using mandibular measurements, but it is not recommended to use these measurements for age estimation.

Keywords: Age Determination by Skeleton; Forensic Dentistry; Mandible; Measurements; Sex Determination by Skeleton.

Figure 1

Didactic scheme for the measurements performed: (A) coronoid height measurement (Cr-Go); (B) determination of the gonial angle (GA); (C) measurement of the bigonial distance (Go-Go); (D) measurement of ramus height (Co-Go); and (E) measurement of the mandible maximum length (Co-Pg).

Figure 2

Formula for sex estimation is developed using the following two measurements: bigonial distance and mandibular ramus. Values higher than 0.5 were classified as male, and if lower than 0.5 they were classified as female.