Question 3

Question 3: 

From the story above so far, how many victims are there? Explain..

We presume that since there was "a whitish, round object resembling part of a human skull" which was excavated, and judging by what Dr Rudi has mentioned, "there is at least one male skeleton, perhaps a young child", we have come to an agreement that there is possibly only one victim in this scenario. Our presumption is that this victim is a young child, of age under 12, and has developed features of a male adult.

Also, "Few pieces of jaw-like structures bearing some teeth" have been found in the same vicinity as the skull. In our assumption, these jaw-like structures originated from the skull of the same victim. Hence, based on these two justifications, we have deduced that there is only one victim in the scenario for now. 

Unfortunately, due to to lack of information from the scenario, we have prepared a table which compares the differences between the skull of an adult and a child. This table will help us to identify whether the bones originated from the same person or not assuming that we have access to the artifacts. If the jaw-like pieces are put together and can be fixed to the skull, then it is likely that there is only one victim. However, in the event when the jaw-like pieces do not fit, then there can be more than one.

Adult	Child
Jaw is bigger	Jaw is smaller
Has bigger and denser skull	Has smaller and less dense skull
Has complete permanent dentition	Has primary or mixed dentition
Growth plate has completely calcified	Growth plate is made of cartilage
Absence of fontanel	Presence of fontanel in infants until 2 years old

Question 2

Question 2

Is a male human skull different from that of a female? If yes, how?

PICTURES!

(click to enlarge)

Left picture : comparisons of brow ridge, mandible, nuchal crest and mastoid process
Middle picture : A=cranial vault, B=eye orbit shape, C=zygomatic process, D=mandible,
 E= width of skull, F=brow ridge, G=teeth
Right picture : slanted frontal bone at different angles

1. How odontology is used to solve crimes
2. Forensic facial reconstruction

Question 1

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 is Forensic Dentistry could be useful in the identification of murder victims?

1. Of burnt victims: 

Enamel can withstand temperatures of more than 1093°C¹. Although other dental treatment structures such as crowns, bridges, fillings or braces may be destroyed or damaged by the heat, they may still support forensic dentists in solving cases of burnt victims.

2. In laboratories or clinics:

Dental charts from clinics are important for identifying the victims as it is not likely for two person to have exactly the same dental treatments done on the same location of teeth respectively. The two most essential details is the type of treatment and the specific location of teeth (eg. the buccal surface of upper right first molar). Example of treatments are: amalgam restoration, extraction (missing tooth), crowning and bridgework. These information can be used to identify burnt and murdered victims where their facial structures are destroyed and unrecognizable. It is also very useful when the bite mark of victim is left on any body parts of a suspected murderer. 

example of dental chart

Dental impressions have similar function as dental charts. It is the imprint of teeth and soft tissues. It provides information of present indentations, abrasions, striations, distances between cuspids, tooth width and thickness, alignment and mouth arch. Impressions are mainly used to confirm or ruling out the identity of a suspected victim. Furthermore, it can also be used to identify the murderer if a bite mark is left on any body parts of the victim.

Reconstruction of a bitemark

example of dental impressions

3. Behind every bite mark lies an untold story:

Forensic odontologists are able to predict the crime (whether it is sexual crime, homicide, child abuse etc) based on the bite mark locations. Studies by Vale and Noguchi (1987), Pretty and Sweet (2000), and Harvey (1976) showed that bite marks on the breast areas are most common in assaulted female victims. Whereas bite marks are not uncommon to be found on arms and legs of abused children.³

Bite mark incidence by anatomical area and type of crime.

Bite depths reflect how much pressure was exerted by the assault on the victim. A 'clear' impression represents significant pressure, while an 'obvious' impression signifies medium pressure and a 'visible' impression reflects violent pressure being exerted.⁴

4. Unfolding an identity

Dental age of a victim can be determined by the number of teeth erupted for primary and mixed dentition. For permanent dentition, there are 2 major methods of analysis. Gustafson method looks at six signs of wear and Lamendin's method judges the transparency of roots. The transparency increases with ageing. The state and wear patterns of an individual's teeth can also give insight into the person's diet, personal habits such as smoking, bruxism or eating disorders. Tailors may have chipped teeth due to their habit of inserting pins or needles into their mouths.

Staining of teeth also aids in identifying of the victim. Since stains are easily recognizable, close friends or relatives of the victim may be asked into questioning to describe the victim's dentition. Smoking can cause staining of tooth surfaces and, over the long term, intrinsic staining of the tooth structure. The use of tetracycline antibiotic from children using developing teeth (aged 3-12 years old) can cause horizontal brown and grey striping of the enamel surfaces. Excessive fluoride from toothpaste and fluoride drops cause brown stains with white flecks. Older people can develop brown staining on the teeth as the enamel wears thin.

Tetracycline staining

5. Extracting DNA:

If no other sources of genetic material can be obtained from a deceased victim, DNA sample can be collected from saliva on bite marks. However, if saliva is not present, DNA can still be extracted from the dental pulp for forensic investigations.

6. Timing is vital: 

Bruising of the bite mark may start to appear from the 4th hour onward up till the 36th hour in live victims². In the event when the victim is already found dead, odontologists may have to wait for the purplish discolouration of the skin to appear in accordance with postmortem lividity. These changes may aid odontologists in estimating the time of occurrence or time of death. 

References:

1,2,4:

http://science.howstuffworks.com/forensic-dentistry.htm>  29 October 2012.1,2,4: Freeman, Shanna.  "How Forensic Dentistry Works"  20 May 2008.  HowStuffWorks.com. 

3:
Adam J. Freeman,D.D.S.; David R. Senn,D.D.S.; and Douglas M. Arendt,D.D.S., M.S. Seven Hundred Seventy Eight Bite Marks:Analysis by Anatomic Location, Victim and Biter Demographics, Type of Crime, and Legal Disposition. J Forensic Sci, Nov. 2005, Vol. 50, No. 6

Part 1

That particular Sunday morning, there was a different kind of air that hung across the morning sunrise. There was an unusual eerie feeling lingering….

People in the Nusantara Damai neighbourhood were extremely curious about the incident that occurred in the vicinity of the park. It was strange indeed; for they would never really have bothered about it on any other day. Today, they really need to know what had happened. They huddled together in groups, whispering to each other, speculating. They may finally never know…

A string of yellow plastic line fenced a small bushy area, guarded by men and women in uniform with cold stare as cold as the morning air. They wouldn’t allow people to cross the yellow line – just another sign that something untoward and unwelcome had happened beyond that line.

Dr. Suria Nuresti, a young promising detective and crime investigator had just arrived at the park. She was told that place was a possible crime scene, although she wasn’t absolutely sure about it. She needed to see it for her to be convinced. She had been assigned as the lead investigator of this case, just to make sure if there was indeed a case.  She was approached by one of the uniformed men whom she showed her badge to and was let past the yellow line.

“What have we got here, doc?” she asked Dr. Rudi Kurniawan, one of the medical examiners that had already examined the place a little while before she got to the scene.

“Well, it seems like we have got ourselves a possible murder scene here but is a little complicated,” Dr. Rudi replied. “A jogger came across this area when her dog started digging into the soil here, and here’s what it found”. 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.

“Cause of death, doc?” Dr. Suria asked, kneeling down on the ground, holding parts of the skull.

“Blunt force on the back of the head? I don’t know…there are too many pieces of evidences to put together.”

“Any possible ID?”

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.”

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 is Forensic Dentistry could be useful in the identification of murder victims?

QUESTION 2

Is a male human skull different from that of a female? If yes, how?

  

QUESTION 3

From the story above so far, how many victims are there? Explain. 

To be continued...