Gender Identification from hyoid bone - An autopsy study

Background - Sexual dimorphism represents a group of morphometric characteristics that differentiate males from females. Limited data is available related to the significance of hyoid bone in sex determination. The objective of this study was to evaluate the utility of hyoid bone for the same. Methodology - An autopsy based cross sectional study was carried out at Kasturba Medical College, Mangalore, by measuring dimensions of Hyoid bones from deceased individuals above 18 years of age, excluding those with fracture and other anomalies. The total outer length, distance between two cornu, length of cornu, anteroposterior length, body height, and body width of hyoid bone were recorded using a digital caliper, by placing the hyoid bone on a flat horizontal surface. The sample size was calculated to be 46 with a 95% confidence level and 90% power with respect to anteroposterior length of the hyoid bone. Ethics committee clearance was obtained for the same. Results - The probability of a person being a male or female was highest by using total outer length. In man, the hyoid bone was larger in total outer length, length of cornu, anteroposterior length, height of body, width of body. Maximum error of estimate was shown by body width followed by distance between two cornu and the minimum error was shown by total outer length. Maximum coefficient of correlation was shown by total outer length followed by anteroposterior length and minimum by width of body. Maximum predictive value was shown by total outer length followed by cornu length and minimum by body width. Conclusion - The need for reliable methods distinguishing males from females based upon various skeletal elements is evident in cases of commingled, eroded and/or missing remains. Sex differentiation is important in the medico-legal system but if the integrity of the body has been compromised, it becomes difficult. Present study clearly shows that hyoid bone is of great importance in forensic medicine practice and can be used efficiently for sexual dimorphism and identification.