Tongue protrusion as an indicator of vital burning

Examining thermally induced movement of the fatal fire victim

Investigating a fatal fire scene comprises analysis not only of the fire's development to identify the point of fire origin and ignition source, but analysis of a victim's position and their relationship within the scene. This work presents both qualitative and quantitative results from experimentation investigating the effect of a real fire environment on the human body, and how the position of a victim at the post burn investigation stage may be significantly different to the position at fire ignition. Qualitative observations were undertaken on the burning of 39 compartment and vehicle scenes from ignition through to suppression, each containing a human cadaver. The results of analysis question the validity of previous work based on cremation observations. Quantitative results were produced by recording 13 points on the body on the X, Y and Z axis, both pre and post burn on a smaller dataset of ten compartment burns. Results have enabled a more robust assessment of thermally induced movement of the body within the scene along each axis, evidencing that pugilism is not the universal reaction of the fatal victim to thermal exposure, with extension of the upper limbs far more common than has been previously reported.

Examination of misconceptions surrounding fatal fire victims

Fire deaths are not unusual in forensic investigative practice but due to the destructive nature of fire they are often very difficult to investigate. With the need to identify the deceased and the events surrounding the manner and cause of death, knowledge of thermally induced alteration to the human body is important. Within the fire investigation community, a number of misconceptions have been present for years regarding the protrusion of the tongue as an indicator of life during the fire, and fractured skulls as the result of brains boiling and skulls exploding. This work presents qualitative analysis on the experimental burning of 42 unembalmed human donated cadavers by the San Luis Obispo Strike Team (SLOFIST) on their annual Forensic Fire Death Investigation Course (FFDIC) between 2017 and 2019. Prior to burning, the position of the tongue within the dental arch was confirmed and sharp, blunt, surgical and gunshot trauma to the cranium documented. Temperature was recorded from ignition through to suppression with thermocouples present both within the scene and the body. Post burn analysis on the position of the tongue, observation of cranial fractures and presence of brain tissue were recorded and analysed in conjunction with thermocouple data, fire scene dynamics and body demographics. The results provide a more comprehensive understanding of the thermal environmental factors involved in producing the phenomena that facilitate these misconceptions, identifying that a more thorough understanding of individual fire scenes and their development is essential when interpreting alteration and injury to the body of the fatal fire victim.

The tongue protrusion in post-mortem fire

Burned bodies raise relevant issues for forensic patologist and odontologist both for the identification and the cause of death and possible vital burning.. The tongue protrusion is regularly investigated for the death caused by strangulation or hanging, whilst seems to be overlooked in case of charred remains as the significance of this sign is still discussed. Different mechanims are hypothized in literature to explain the toungue protrusion both for vital and non-vital burning. This paper retrospectively evaluates some cases of carbonized corpses examined at the Forensic Pathology service of the University of Florence. The tongue protrusion shows a high occurrence both in vital (100%) and non-vital fires (66%). The involvement of a forensic odontologist in the cadaver examination result to be limited to one third of the cases. In two non-vital cases the tongue was described as protruded and clenched between the dental arches. The rigor of the genioglossus induced by the heat could explain the phenomenon. Further research on fire fatalities is required to analyze the tongue bleeding as a possible parameter to discriminate the vital by the non-vital tongue protrusion. Moreover, the mechanism at the origin of vital and non-vital tongue protrusion, the different position of the tongue (protruded from an open mouth, protruded and clenched between the dental arches, etc.) in different death circumstances, should be furtherly investigated with a meaningful collaboration between forensic pathologists and odontologists for a complete registration and interpretation of all the mouth originated evidence.

Tongue position and its relation to the cause of death and sequential stages of body decomposition observed during 608 forensic post-mortems

The purpose of this study was to document tongue position and its relation to the cause of death and sequential stages of body decomposition, as observed during the routine forensic pathological examination of bodies. The sample of 608 included all bodies examined by the first and third authors during the period April 2016 to September 2016. Tongue position was recorded in all cases where position of the tongue could be visually determined. The condition of the body was recorded as follows: fresh flaccid, fresh with rigor mortis, early decomposition, and advanced decomposition. The cause of death was recorded where known. The results showed that 86% of all bodies examined did not show a protruded tongue and that 92.8% of the bodies were in a state of fresh rigor mortis. The study also showed that tongue protrusion was more prevalent in certain causes of death, namely, hanging, burning, and drowning, but was never absolute. The authors believe that due to the low numbers of bodies presenting with protruded tongues, this phenomenon has previously been overlooked, the significance thereof underestimated, and the pathophysiology and pathomorphology never fully investigated.

Burned bodies: post-mortem computed tomography, an essential tool for modern forensic medicine

Abstract

Currently, post-mortem computed tomography (PMCT) has become an accessible and contemporary tool for forensic investigations. In the case of burn victims, it provides specific semiologies requiring a prudent understanding to differentiate between the normal post-mortem changes from heat-related changes. The aim of this pictorial essay is to provide to the radiologist the keys to establish complete and focused reports in cases of PMCT of burn victims. Thus, the radiologist must discern all the contextual divergences with the forensic history, and must be able to report all the relevant elements to answer to the forensic pathologist the following questions: Are there tomographic features that could help to identify the victim? Is there evidence of remains of biological fluids in liquid form available for toxicological analysis and DNA sampling? Is there another obvious cause of death than heat-related lesions, especially metallic foreign bodies of ballistic origin? Finally, what are the characteristic burn-related injuries seen on the corpse that should be sought during the autopsy?

Teaching points

• CT is highly useful to find features permitting the identification of a severely burned body.

• PMCT is a major asset in gunshot injuries to depict ballistic foreign bodies in the burned cadavers.

• CT is able to recognise accessible blood for tests versus heat clot (air-crescent sign).

• Heat-related fractures are easily differentiated from traumatic fractures.

• Epidural collections with a subdural appearance are typical heat-related head lesions.

Multiple deaths caused by a fire in a factory: identification and investigative issues

The article presents a case of multiple casualties following a textile factory fire. The incident required a full DVI team similar to large mass-disaster because of the specific operational aspects and identification difficulties. The autopsy results were consistent with death by fire and the toxicological investigations revealed carbon monoxide poisoning in four cases (HbCO% ranging between 88,05 and 95,77), two deaths by cyanide intoxication (with concentrations between 5,17 and 8,85 mcg/ml), and in one case there was a synergistic effect of the two substances (carbon monoxide and cyanide). The identification, carried out in accordance with INTERPOL protocols, encountered serious difficulties in the AM phase primarily due to a language barrier and the lack of any dental or medical information relating to the victims. Secondary identifiers proved to be very useful in corroborating possible identities. As a result of the combined efforts of a team of experts the identity of each victim was determined and in all cases at least one primary identifier was used in the identification process. The deployment of DVI teams composed of forensic experts from different fields of expertise and well acquainted with DVI procedures, is essential in events involving multiple casualties that may also include foreign victims. The DVI team should intervene not only in PM examinations but also in the collection of AM data for those individuals not accounted for and by helping police in contacting families of missing people.

Tongue protrusion in burned bodies

Protrusion of the tongue is a common, though often neglected finding in fire fatalities. According to a study recently published by Bernitz et al., it is an indicator of vital burning. This statement has been doubted repeatedly. Retrospective analysis of 61 fire fatalities from our own autopsy material did not show any statistically significant increased incidence of tongue protrusion in deaths with vital exposure to heat. Similarly, there was no correlation with the degree of destruction by the fire in general or the extent of cervical burning. Further prospective studies seem to be necessary also with regard to the pathophysiological processes.

Protrusion of the tongue in bodies burned after death: Two cases of arson to cover homicide

In the forensic assessment of burned bodies, the question of whether the victim was exposed to fire before or after death is of crucial importance. Many authors consider tongue protrusion in cases of burned bodies to be a post-mortem phenomenon. Deep-heating effects of fire are sufficient to cook muscle. The muscle becomes shortened by dehydration and protein denaturation. Exposure to heat causes flexion of the extremities on the contraction of muscles and tendons - heat rigour. The flexors, being bulkier than the extensors, contract more and force the limbs into the position of general flexion. The genioglossus is the major muscle of the tongue and is responsible for protruding or sticking out the tongue: by means of its inferior fibres, it draws the root of the tongue forward and protrudes the apex from the mouth. Similar to the action of limb flexors exposed to heat and the appearance of post-mortem general flexion of a burned body due to heat rigour, perhaps the geniglossus could be shortened by heat, causing post-mortem tongue protrusion to appear as heat rigour of the tongue. In this paper, we present two such cases of protrusion of the tongue in bodies burned after death - cases of arson to cover homicide.