Mandibular ramus length as an indicator of chronological age and sex

Abstract

Age and sex estimation is crucial in forensic investigations, whether in legal situations that involve living people or to identify mortal remains. The aim of this study was to establish reference values in a Brazilian population to estimate age and sex by measuring the length of the mandibular ramus on lateral cephalometric radiographs, and to determine the probability that an individual being is 18 years or older, based on the results that were obtained. Two hundred and eighteen scanned lateral cephalograms of individuals between 6 and 20 years of age (101 males and 117 females) were measured with reference to mandibular ramus length (the distance between Condylion superior (Cs) and Gonion (Go)) using ImageJ 1.41 software (NIH, Bethesda, MA, USA). The results showed that sexual dimorphism was not observed until 16 years and, based on the ramus length measurements in this sample, it is possible to predict sex with an accuracy of only 54 %. There was a positive correlation between age and ramus length (r = 0.90; p < 0.001). From the linear regression analysis, one formula was derived; therefore, it was possible to calculate the individual's age, given his or her ramus length. The results showed that if an individual's ramus length is 7.0 cm or more, then there is an 81.25 % chance that the individual is 18 years old or older. In conclusion, the mandibular ramus length was not effective in discriminating sex. Mandibular length is strongly related to chronological age and can be used to predict whether an individual is 18 years or older with high degree of expected accuracy.

Mandibular Ramus linear measurements as an Indicator of Chronological Age and Sex in Egyptian Population

“…These results are in accordance with those obtained by De Oliveira et al [11] , who studied the length of the ramus of the mandible as an indicator of age and sex in a group of Brazilians. They found that sex could not be distinguished based on the mandibular ramus length measurement until the age of 18 years, and that measurement could be used to determine sex with an accuracy of only 54% using lateral cephalometric radiographs.…”

Mandibular Measurements for Sex and Age Estimation in Brazilian Sampling

“…In our study it was not possible to use the same size of samples in each age group, however, this was also the case in other studies ( 17 , 19 , 26 ) and in those, it was considered effective for age estimation. Gonial angle showed to increase with age ( 19 , 27 ), but another study found that this measurement decreases with age ( 26 ), which seems to be more logical, since the angle is inversely proportional with the measurement of the mandibular ramus which increases with age ( 19 , 28 ). In this study, the bigonial distance did not have values with an increase or decrease pattern, agreeing with another study ( 17 ).…”

“…This probably brings some complications to our results for age estimation. However, with a regular number of sample ( 27 , 28 ) or with different size of samples in each group ( 17 , 19 , 26 ), it was considered effective for age estimation, with high degree of accuracy ( 28 ).…”

Age‐dependent changes of the mandible bone throughout the lifespan in female F344/N rat

“…The mandible is also affected by age and is commonly used as an indicator of age in humans (de Oliveira et al. ; Leversha et al. ), and it is known that various mandible regions change with age, including the gonial region, antegonial region, condyle, and ramus in humans (Ghosh et al.…”

“…In terms of model animals, morphological examination of the mandible showed substrain differences among F344/DuCrlCrlj, F344/Jcl, and F344/NSlc rats (Tanaka et al 2006a,b). The mandible is also affected by age and is commonly used as an indicator of age in humans (de Oliveira et al 2015;Leversha et al 2016), and it is known that various mandible regions change with age, including the gonial region, antegonial region, condyle, and ramus in humans (Ghosh et al 2010).…”