Fracture of the hyoid bone in strangulation: comparison of fractured and unfractured hyoids from victims of strangulation.

The hyoid is the U-shaped bone of the neck that is fractured in one-third of all homicides by strangulation. On this basis, postmortem detection of hyoid fracture is relevant to the diagnosis of strangulation. However, since many cases lack a hyoid fracture, the absence of this finding does not exclude strangulation as a cause of death. The reasons why some hyoids fracture and others do not may relate to the nature and magnitude of force applied to the neck, age of the victim, nature of the instrument (ligature or hands) used to strangle, and intrinsic anatomic features of the hyoid bone. We compared the case profiles and xeroradiographic appearance of the hyoids of 20 victims of homicidal strangulation with and without hyoid fracture (n = 10, each). The fractured hyoids occurred in older victims of strangulation (39 +/- 14 years) when compared to the victims with unfractured hyoids (30 +/- 10 years). The age-dependency of hyoid fracture correlated with the degree of ossification or fusion of the hyoid synchondroses. The hyoid was fused in older victims of strangulation (41 +/- 12 years) whereas the unfused hyoids were found in the younger victims (28 +/- 10 years). In addition, the hyoid bone was ossified or fused in 70% of all fractured hyoids, but, only 30% of the unfractured hyoids were fused. The shape of the hyoid bone was also found to differentiate fractured and unfractured hyoids. Fractured hyoids were longer in the anterior-posterior plane and were more steeply sloping when compared with unfractured hyoids. These data indicate that hyoids of strangulation victims, with and without fracture, are distinguished by various indices of shape and rigidity. On this basis, it may be possible to explain why some victims of strangulation do not have fractured hyoid bones.