Suspension-associated dislocation of the jaw in hanging

Abstract

Hanging is a common type of death, and the role of the medical investigation of such deaths by a forensic pathologist not only requires the determination of the cause of death but providing information to assist in the determination of the manner of death. The forensic pathologist should be well versed in the spectrum of injuries known to be associated with neck compression, to document injuries known to be associated with hanging, but also to identify those that are inconsistent with self-inflicted hanging or that may suggest the involvement of a third party in the death. Comprehensive identification and correct interpretation of external and internal injury are crucial for the appropriate degree of police and coroner/medical examiner investigation. We present two cases of deaths believed to be caused by self-inflicted hanging that were observed to have unexpected unilateral dislocation of the temporomandibular joint identified on routine post-mortem computed tomography, without any evidence of involvement of a third party. This injury was unexplained and had not been previously observed at our Forensic Institute nor was it identified after a review of the published biomedical research literature. Issues regarding the cause of this abnormality, possible mechanisms, and the medicolegal significance of this finding will be discussed.

Keywords: Autopsy; Hanging; Neck compression; Post-mortem computed tomography (PMCT); Temporomandibular dislocation; Temporomandibular joint.

Fig. 1

a Left lateral view, b posterior view of case 1 ligature, being a woven rope ligature fashioned as a “hangman-style” noose with a suspension point behind the left ear (left posterior)

Fig. 2

Case 1 three-dimensional reformat of the PMCT head: a anterior view showing right-to-left deviation of the mandible with a left crossbite, b right lateral view, and c sagittal image showing right mandibular condylar head displacement (arrow) anterior to the articular eminence (star)

Fig. 3

Case 1 three-dimensional reformat of the PMCT head showing the external appearance of the jaw, with deviation to the left. The rope ligature is in situ with a left posterior suspension point

Fig. 4

Case 2 three-dimensional reformat of the PMCT head: a anterior view showing a right crossbite, b left lateral view showing a near-closed mouth with left mandibular condylar head displacement anterior to the articular eminence (arrow), c right lateral view showing a right condylar head congruous with the condylar fossa (star)

Fig. 5

Case 2 with a subtle deviation of the jaw toward the right side

Fig. 6

Case 2 three-dimensional reformat of the PMCT head demonstrating the ligature furrow with the likely suspension point behind the right ear (arrow)