QUESTION 1
We have all heard of how Forensic Dentistry has helped in the identification of burnt victims and also victims with bite marks. Explain more about these and describe how Forensic Dentistry could be useful in the identification of murder victims.
We have all heard of how Forensic Dentistry has helped in the identification of burnt victims and also victims with bite marks. Explain more about these and describe how Forensic Dentistry could be useful in the identification of murder victims.
A forensic dentist requires dental records to identify the deceased; without them, there is nothing to compare the findings with and any effort put into this area would likely be fruitless. With access to dental records however, a surprising amount of information can be gathered due to the sheer hardiness of the teeth, despite extensive destruction to the rest of the body.
The outer layer of teeth (enamel) is the hardest substance in the human body, and hence teeth remain far longer as compared to the other parts of the body. Victims of disfiguring burns are often identified by their teeth, which can withstand intense temperatures of more than 1090°C. Teeth that have been through extreme heat tend to be fragile and may shrink, but they can be layered with lacquer and used for identification if handled with care. Dental restorations or crowns, like gold crowns, will be distorted by fire but may otherwise still help with identification.
To identify a person from his or her teeth, a forensic dentist must first have dental records from the deceased’s dentist. In incidents with multiple deaths, forensic dentists receive a list of possible persons and compare existing records with the teeth. Examining the teeth of an intact corpse often requires working in a morgue to expose the jaws by surgery. Even if only a few teeth are available, a forensic dentist can still make a positive identification. The best comparisons would come from radiographs. If those aren't available, tooth charting and notations can assist the dentist in determining which teeth are the same.
Identifying a person by his or her teeth without dental records is much harder. However, things like missing teeth, broken teeth and gold crowns might be recognised by the family members or friends of the deceased. Information and certain clues can be extracted from the teeth and the bite of the deceased; for example, a bagpipe player or a pipe smoker will have a distinctive wear and tear pattern. Dressmakers and tailors, who often put pins and needles between their teeth, may have chipped teeth.
Forensic investigators can also retrieve DNA samples from the pulp from the centre of the tooth. Unlike the enamel, pulp can be damaged by heat and other extreme conditions, but it can also last for centuries. Dental identification is often the last option, and it isn't always possible — some people simply cannot be identified despite a forensic team’s best efforts.
Bite-mark Analysis
Bite-mark analysis is extremely complex, with many facets involved in a forensic dentist's technique and ability to identify the perpetrator.
The movement of a person's tongue and jaw when he or she bites contributes to the marking on the surface or material. Depending on the location of the bite, it is sometimes common to find bite marks where both the upper and lower teeth leave clear impressions - usually one or the other is more visible. If the victim was moving while being bitten, the bite would look very different from that inflicted on a stationary and still victim.
If an investigator observes something on a victim that even resembles a bite, the forensic dentist must be summoned immediately, because bite marks change rapidly and significantly over time. For example, if the victim is deceased, the skin may move as the body decays, causing the bite to slip to a different location or distort the bite mark entirely.
The first step in analysing the bite is to identify it as a human bite mark. Different bite-mark patterns are left because human teeth are very different from an animal’s. Next, the bite is swabbed for DNA remnants, which may have been left in the saliva of the biter. The dentist must also determine whether or not the bite was self-inflicted.
The forensic dentist then takes photographs and measurements of each bite mark and records it. This is done because of the changing nature of the bites. Bruising can appear 4 hours after a bite and disappear after thirty six hours. If the victim is deceased, the dentist may have to wait until the pooling of the blood, or lividity stage, clears and details are visible. The photography of the bite must be conducted accurately, using rulers and other scales to accurately depict the size, orientation and depth of the bite. The photos are then enlarged, enhanced and corrected for aberrations and distortions.
Finally, bite marks on deceased victims are carefully cut out from the skin in the morgue and preserved with a compound called formalin, which contains a high percentage of formaldehyde.
A silicone cast of the bite mark is then made by forensic dentists.
A silicone cast of the bite mark is then made by forensic dentists.
Forensic dentists use several different words to describe different types of bite marks:
Contusion - a moderately sized bruise
Incision - a neat, clean wound
Abrasion - a scrape on the surface of the skin
Incision - a neat, clean wound
Abrasion - a scrape on the surface of the skin
Avulsion - a bite resulting in the removal of part of the skin
Haemorrhage - a profusely bleeding bite
Artefact - when a piece of the body, such as a finger, is removed through biting
Laceration - a puncture wound that may or may not be bleeding
Furthermore, there are a few different types of markings that may be left by teeth, depending on the pressure applied by the biter. A clear impression equates to significant pressure; an obvious bite signifies moderate pressure; and a noticeable mark means that the perpetrator used a large amount of force to bite down.
Based on the bite mark, a forensic dentist can tell a lot about the teeth of the biter . If there is a gap in the bite, the biter is most probably missing a tooth. Crooked teeth leave crooked markings, and chipped teeth leave irregular impressions of differing depths. Braces and other prostheses or restorations also leave distinct impressions.
Once the investigators have singled out a suspect, they acquire a warrant to take a mould of his or her dentition as well as photos of the mouth in various instants of opening and biting. They then juxtapose transparencies of the mould with those of the bite-mark cast, and images of both the bite mark and the suspect's teeth are set side by side to look for similarities.
QUESTION 2
Is a male human skull different from that of a female? If yes, how?
Before delving into the differences between the male and female skull, it should be noted that none of these features should be looked at in isolation. When looked at in combination with each other however, they tend to be a reliable indicator as to the gender of the skull. With that in mind, let’s look at some of the differences between human male and female skulls.
1. Thickness of the skull
Men, the next time your wife or girlfriend calls your thick-skulled or big-headed, tell them you can’t help it. Men generally have thicker, heavier and larger skulls than females!
2. Temporal lines
The temporalis muscle is a long, fan-shaped band of tissue that extends from the parietal bone to the mandible. The part of the skull from which this muscle originates (the temporal line) has a more pronounced ridge in males than in females.
Is a male human skull different from that of a female? If yes, how?
Before delving into the differences between the male and female skull, it should be noted that none of these features should be looked at in isolation. When looked at in combination with each other however, they tend to be a reliable indicator as to the gender of the skull. With that in mind, let’s look at some of the differences between human male and female skulls.
1. Thickness of the skull
Men, the next time your wife or girlfriend calls your thick-skulled or big-headed, tell them you can’t help it. Men generally have thicker, heavier and larger skulls than females!
2. Temporal lines
The temporalis muscle is a long, fan-shaped band of tissue that extends from the parietal bone to the mandible. The part of the skull from which this muscle originates (the temporal line) has a more pronounced ridge in males than in females.
3. The eyes
The lower section of the orbit differs slightly in men and women. Women tend to have a sharper ridge, while men tend to have a slightly blunter surface. On a side note, this explains why men and women will never see eye-to-eye. It’s science, I tell you.
4. The golden arches
The superciliary arch (a.k.a. the ‘monkey brow’) isn’t usually very prominent in humans. These arches are above the orbits, and are arched elevations which are medially prominent. Male humans usually show some slight ridging, while females typically show very little or none at all.
5. Not by the hairs on my chinny chin chin!
This one’s a no-brainer. Men tend to have squarer chins, while women tend to have more pointed chins.
6. Off the top of my head..
The forehead of a human male usually slants backwards, while a female will have a more rounded forehead. The vault of the skull differs as well; males have a more rounded vault, whereas females have a more flattened vault.
The lower section of the orbit differs slightly in men and women. Women tend to have a sharper ridge, while men tend to have a slightly blunter surface. On a side note, this explains why men and women will never see eye-to-eye. It’s science, I tell you.
4. The golden arches
The superciliary arch (a.k.a. the ‘monkey brow’) isn’t usually very prominent in humans. These arches are above the orbits, and are arched elevations which are medially prominent. Male humans usually show some slight ridging, while females typically show very little or none at all.
5. Not by the hairs on my chinny chin chin!
This one’s a no-brainer. Men tend to have squarer chins, while women tend to have more pointed chins.
6. Off the top of my head..
The forehead of a human male usually slants backwards, while a female will have a more rounded forehead. The vault of the skull differs as well; males have a more rounded vault, whereas females have a more flattened vault.
QUESTION 3
From the story above so far, how many victims are there? Explain.
Related info from the article
He pointed to the ground where a whitish, round object resembling part of a human skull, had been dug out.
“Only a skull?” Suria asked again.
“Well, we also have a few pieces of jaw-like structures bearing some teeth. We are still searching the parameter for body parts or of any human remains”. Dr. Rudi explained.
Dr. Rudi shrugged and shook his head, “This skeleton must have been buried for such a long time, at least a few months. Even if there is any sort of identification, it would most probably have disappeared by now. But by the looks of it, I am pretty sure there is at least one male skeleton, perhaps a young child.”
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With the limited information given, we can only determine that there is likely to be only one victim (the male child mentioned by Dr. Rudi). However, the pieces of jaw-like structure leave room for the possibility of more victims, possibly someone related to the child. However, it is difficult to come to a conclusion without additional details regarding the size and shape of the jaw pieces, as well as the dentition attached to each of them.
Some speculation among our group members brought us to believe that if indeed there are more victims, the other victims could possibly be
a) the young male child’s parent(s) or another close relative
=> the child may have been with an adult (likely a parent) at the time of the murder
b) the young male child’s friend(s)
=> in the case of a kidnapping gone wrong, the young male child may not be the sole victim.
=> the child may have been with an adult (likely a parent) at the time of the murder
b) the young male child’s friend(s)
=> in the case of a kidnapping gone wrong, the young male child may not be the sole victim.
Whichever the case may be, it is unlikely that the site of the murder is the park itself, as in the event that killing the victim in public becomes necessary, it would be difficult to both silence the victim(s) and prevent him/them from running away, especially if the perpetrator was acting alone. The park may simply have been the perpetrator’s choice of a site to dump the bodies (not a very good idea). If so, there may be other skeletons buried in the area and hence, other victims.
Now go for the next part....
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