Abstract:

Objective To evaluate the sexual dimorphism in the sternum, and further to investigate whether a correlation exists between the sternal variables and the length of the clavicle and femur. Methods We examined intact sterna, clavicle and thighbone from 45 Macaca mulatta (13 males and 32 females). Six linear variables, including four sternal variables, length of clavicle and length of femur, were measured. Statistical analysis was done using SPSS 22.0 package, and t-test was used to determine the difference between sexes. A receiver-operator characteristic (ROC) curve analysis was conducted in order to identify the sensitivity and specificity of gender identification of each variable. The sex discrimination rate of each variable was derived using the discriminant analysis. Results The sexual differences of sternal variables were statistically significant (P<0.05). The correct discrimination rate was higher in anterior width of sternum (84.4%) and relatively lower in posterior width of sternum (66.7%). The correlation was higher between sternal variables and length of clavicle and weaker between sternal variables and length of femur. The error was larger when estimating stature using manubrium. Conclusion The manubrium of Macaca mulatta can be used for estimation of sex. The principal factors influencing sternum morphology may be locomotor and habit behavior.

Key words: Sternum, Sexual dimorphism, Stature, Linear measurement, Receiver operator characteristic curve analysis, Macaca mulatta