The Awesome Closure

So what's the story behind?

This one is a story of deception, betrayal and regret. 

After months of investigations, it all finally boils down to this. 

The widowed Harman Hartono and his son Adi lived together in a run-down neighborhood. Mr Harman was critically ill and was in desperate need of money for his treatment.  

Unable to afford the treatment fees, all kinds of dangerous thoughts were racing through Adi's mind and he ultimately got in contact with some mobsters involved in human trafficking and organ harvesting. They asked Adi if he could bring them any girl around the age of 10 in exchange for his father's treatment fees, paid in full. 

Anya and her twin sister unfortunately happened to be Adi's neighbors and were therefore his easiest preys. He kidnapped the unlucky Anya and held her captive in a warehouse nearby. 

One day Mr Harman followed Adi where he was shell-shocked to find the little girl. Adi, now fearing conviction, did not want to let the little girl go and subsequently got into a fight with his dad.  

While struggling, Adi pushed his dad onto a rock by mistake and chased the girl who was freed byMr.Harman. The latter laid unconscious after his head was injured.

In a state of rage, Adi did not hold back and unknowingly strangled the little girl ….

By the time he realised kidnapping had escalated to two murders, he decided to come  clean. However, bythen, the mobsters were already there and were not going to let that happen.  

They killed Adi, beheaded the three, took away the bodies and buried the remains. Gruesome.
Few months later, some dogs happened to sniff the decayed remains. The rest is history.

Part III: Murder Most Brutal! Q7

Evidences we have collected at the crime scene

Evidence 1 : human skull with large jaw bearing five teeth

Evidence 2 : jaw bearing three back teeth

Evidence 3 : jaw with some teeth still in eruption

The DNA profile showed evidence for a father and son, and DNA profiling pattern that matched one living twin (Tanya Rosilawati).

List of missing person : Herman Hartono and his son, Adi Hartono who lived a few blocks away from here. Also, Anya Suriati and Tanya Rosilawati, a pair of 9-year old twin girls, whose father filed a missing person’s report of Anya four months ago


Before we analyse the evidences, let’s talk about the DNA profiling techniques and also the extraction of DNA from then bones and teeth.

There are 2 DNA profiling techniques. The techniques are Restriction Fragment Polymorphis(RFLP) and Polymerase Chain Reaction(PCR).

• Restriction Fragment Polymorphis

Restriction fragment length polymorphism or RFLP analysis is used to identify a change in the genetic sequence that occurs at a site where a restriction enzyme cuts. It is usually used to trace inheritance patterns, identify specific mutations, and for other molecular genetic techniques.

Figure 1 : Steps for RFLP analysis

•  Polymerase chain reaction

PCR (polymerase chain reaction) analysis is usually the first step in the creation of a DNA profile today. PCR can replicate a small amount of DNA to create a larger sample for analysis. It does this using a repeating process that takes about five minutes.

Steps for PCR analysis :

1. Add a heat-stable DNA polymerase into the DNA sample to bind to the DNA and allows it to replicate.
2. Heat the DNA sample to 200 degrees F (93 degrees C) to separate the threads.
3. Let the sample to cool after heating then reheat it again. This is because reheating will double the number       of copies.
4. Repeat this process about 30 times, so that there is enough DNA

Figure 2 : How PCR works

PCR is the first step in analysing Short Tandem Repeats(STRs- very small, specific alleles in a variable number tandem repeat). Apparently, analysing STRs is more accurate than the RFLP technique because their small size makes them easier to separate. Y-STR is a variation on STR analysis and it is the only STRs found on the Y-chromosome (which only males have) is analysed.

Figure 3 : Y-STR profile

Steps for DNA extraction from ancient teeth and bones.

Figure 4

Now, we shall start analysing our evidences. We will start off with evidence 3, which is a jaw with some teeth still in eruption. Matching the DNA profile and also the list of missing person, we can believe that the victim is Anya Suriati. Firstly, Anya Suriati is 9-year old girl, not all teeth will be erupted at that age, and this point has fulfilled the evidence 3. To double confirm this, DNA extracted from the tooth attached to the jaw(evidence 3) matches with Tanya Rosilawati’s DNA, which is Anya Suriati’s twin. Identical twins have the exact same DNA because they came from the same fertilized egg as shown in Figure 6. Thus, with all these evidence, we can conclude that evidence 3 belongs to Anya Suriati.

Figure 5 : DNA profile of identical twins

 

Figure 6: Fertilisation of one ovum by one sperm resulting in identical twins as shown.

Now there are 2 unidentified evidences left, evidence 1 which is the human skull with a large jaw bearing 5 teeth and also evidence 2 which is a jaw bearing 3 back teeth. Both evidences were from 2 different individuals. According to the DNA profile, it showed evidence of a father and son. To confirm the relationship of a father and son, DNA extracted from both evidence 1 and 2 are compared. The two DNA profile pattern matches half of it or by analysing both their Y-STR(as mentioned above) will confirm their father and son relationship.

Again, by matching the DNA profile with the list of missing person, we can believe that these 2 evidences from 2 different victims were belong to Herman Hartono and his son, Adi Hartono.

We can also conclude that both these jaws are belong to victims 17 years and above because both jaws have their 3rd molar(wisdom tooth) erupted already. We cannot differentiate between the evidences if it belongs to the father or the son unless the DNA of the victim Adi Hartono’s mother is collected also. Whichever tooth(from either evidence 1 or 2) has its DNA profile pattern matches half of the DNA profile pattern of the victim Adi Hartonno’s mother will show that that particular evidence belongs to the son and the other one belongs to the father. This is because the mother and father does not share the same DNA. Refer to Figure 7.

Figure 7 : The DNA profile pattern of child and parents.

Part III: Murder Most Brutal! Q6

Judging by the size of the bones and the number of tooth sockets (8 adult teeth/alveolar processes) per quadrant, the above is part of adult remains. It might be either Herman Hartono or his son Adi. We can observe two mandibular third molars here and an acute angle of the mandible. Since 3^rd molars erupt around the age of 17-25, we can assume the son was at least 17 years of age. Round and large orbits also indicate the above belongs to a male victim.

The teeth above are definitely from an adult dentition. They are the 1^st, 2^nd and 3^rd molars.

The third molar is the smallest of the three. The second molar is smaller than the first one and has 5 cusps. The first molar is the largest posterior tooth and has 4 cusps.

The angle of the above mandible indicates a male victim.

The last piece of evidence shows a child’s mandible. It is not clear enough whether the canine is deciduous or permanent. However as Anya Suriati was 9 years old, we could assume it is a permanent canine as the latter erupts around that age. We assume it is Anya Suriati’s as she was the only missing child filed.

An intriguing fact here is that Anya was only reported missing 4 months ago and yet her body has been fully decomposed. As discussed in the previous parts, decomposition depends on various factors.

For example, the temperature, humidity, insects and soil acidity can all speed up decomposition.

Evil Raccoon:

Part II: Murder Most Brutal! Q5

So, Dr. Rudi and Dr. Suria is presented with a number of evidences.
Until now we have :
1. Parts of a human skull (with most cranial bones lost)
2. Mandible with five teeth
3. Mandible with some teeth still in eruption
4. Right part of mandible bearing three posterior teeth

 As spoken of in the previous post, there are various ways and steps involved in solving a homicide. In fact, some peculiar ways too!

 Some of you might not catch the humour this clip on "The Mentalist" portrays. Nevertheless, the course of investigation is clear - that every detail adds up to a final conclusion.

What have we done 'till now? 
1. Recovered several pieces of bones 
2. Determined it is of human origin 
3. Determined the sex of the deceased  

The question is, how are we to move on? 

 1. Make a thorough search for other evidence in the area, witnesses, collaborative facts regarding the death of people in that area
  Many mundane things which appear of no relevance might be closely related to the case. The investigation team is to relate the possible missing persons with the site of discovery of the bones; taking into consideration that:
a. It is difficult to distinguish which is exactly related to the current case
b. Not sure if the area is truly the crime scene

2. Identify parts of bone pieces,matching it to know whether it belongs to an individual or separately
  What we expect:
a. Incomplete parts to match the pieces of puzzle - an amount of deduction required
b. Shape of skull and jaw not enough to determine how many victims and who they are
c. Further tests (in previous post) to determine whether each part belongs to the same individual or not

3. Estimate age of individuals, time of death
Time of death estimates based on environmental factors will be found as follows: 
3 weeks -- articulated bones
5 weeks -- some scatter, some articulated
4 months -- disarticulated, within 10' circle
7 to 8 months -- most bones w/in 10' circle and all w/in 20'
1 year -- small bones missing, complete disarticulation
2 to 4 years -- some bones broken, scatterd 40', some large bones missing
12+ years -- bone rot; partial burial*
15 to 20 years -- no surface evidence

* partial burial from leaves, storms, erosion from shallow burial

Current methods of age estimation include simple, yet less precise morphological methods (such as evaluation of dental or skeletal morphology) or more complex, yet more accurate laboratory methods (such as racemization of aspartic acid in dentin or tooth enamel or radiocarbon dating of tooth enamel). 

4. Investigate injuries and cause of death
  With little or no flesh remaining, it may be the duty of the forensic anthropologist to seek out clues as to how the victim died and what injuries they received. Whereas in many cases it may be impossible to tell, some injuries do leave tell-tale signs on the bones.

  a. Sharp blades such as knives, if plunged into the body deeply enough, will often leave nicks and grooves on the surfaces of any bones they come into contact with. When the blade meets the solid structure of the bone, it is also possible that fragments of the blade are broken and left behind with the remains, ideal for later comparison to weapons. Such discovered fragments may be matched directly to the weapon used, or they may at least give some indication as to the type of weapon.

b. A bullet may leave numerous markings on bones. If the bullet passed straight through bone, distinct holes could be observed. Such a projectile also has the potential to completely shatter a bone, or at least leave noticeable scratches across the surface. It is possible that bullets may have been left behind in the remains, stuck in one of the bones or caught up in leftover tissues.

c. The hyoid bone is a small, U-shaped feature in the centre of the throat. If this bone is found broken, it is likely that strangulation has occurred, though it cannot be positively determined at this point that this was the cause of death.

d. Forceful blows to the skull will often leave obvious fractures or even holes, the study of which can even aid in the identification of the murder weapon, more so if a narrower, sharper weapon was used. The use of a larger, blunt object produces wounds described as blunt force trauma. Blunt force trauma may leave a pattern of radiating fractures around the point of impact (Depressed fracture), the extent of these fractures indicating the force of the blow. 

If there are multiple blows to the skull, any radiating fracture lines from following strikes will stop at existing fracture lines (Leads to compound fractures). The study of these can determine the order in which the injuries were received. The skull itself is composed of a spongy layer of bone sandwiched between two harder bone layers. The inner side of the skull is cushioned by the outer and middle layers, thus is can be assumed that great force was employed if all three layers are shattered.

5. Match evidences and deductions to missing people
 After a profile of the victim has been made, we can compare the victim’s characteristics to persons who went missing in the calculated time-frame. Possibly we might face the following problems:
a. Test results and deductions might be inaccurate
b. Inadequate information to come to any conclusion

In a nutshell, we try to reach the most logical deductions using the evidences we have, backed up by several tests to reach a conclusion for the case at hand.

Hope this post was helpful to you guys!

PART II : MURDER Most Brutal! Q4

Other than examining the dental aspects provided as evidence, what other ways can the victims be identified?

Face Reconstruction

There are two methods of forensic art to reveal a facial likeness of unidentified human using the skull, which are the two-dimensional and three-dimensional facial reconstruction. Facial reconstruction often helps in image building for the investigators in identifying the victims when there are only remnants of the skeleton found. In facial reconstruction, a cleaned skull will be used to construct a digital 3D model of the skull. Tissue depth markers pertaining to the unknown individual’s sex and ancestry are glued onto anatomical facial points of the skull to determine an average shape for that particular face. Artificial eyes are placed in the eye sockets and clay will be applied on the skull following the skull’s contours. Various measurements like the nose thickness, mouth width and eye placement are made and logged. Sometimes props such as spectacles and wig are use on the reconstructed model to better accentuate the features of the individual. . Upon completion, the sculpture is photographed

Referring to the case discussed, the skull found can be used for face reconstruction. The reconstructed model can help to determine if the victims are one of the missing person when compared to the pictures of the missing person. This indirectly helps to identify the victim.

Please refer to this video for a better understanding as this video has clearly shown the procedures on face reconstruction.

Forensic Entomologist

These experts can estimate work out the approximate time of death by analysing the insects that are feeding on a body because different stages of decomposition of the body attracts different kinds of organisms to feed off the body. Besides, the entomologist have to take into considerate about the weather conditions, humidity and temperature, if the body has been buried or are exposed to the elements, body size and weight, clothing, as all these will either increase or decrease the rate of decomposition of the body. The estimated time of the victim’s death can be used to see if it matches with the list of people who are reported missing around that particular time.



Forensic Anthropologists

By examining skeletal remains, a large amount of information can be derived by these experts. Information like age, sex, stature, special characteristics of a human can be revealed through the 206 bones in an adult human. 

We can identify the sex of the skeletal remains by looking at its pelvis bone and size of the skull, adult males tend to have narrower pelvises and a larger skull .Age can be estimated by the degree of the bone growth, eruption of the tooth, calcium and mineral deposits in the bones. Our "bones" are mostly soft cartilage at birth. The cartilage is replaced by hard bone at different centers of growth as we grow. In infants, there are over 300 centers of bone growth which fuse to form the 206 bones in the adult body. Since the centres grow and fuse at known rates, anthropologists can use the pattern to estimate age in children and subadults. Besides, the shape of the skull can also tell if its racial, whether its a Negroid, Caucasoid or Mongoloid heritage. The forensic anthropologists can identify special characteristics such as past injuries or fractured by examining the bones.


All the information found from a skeletal remains can be used to compare with the characteristics of each of the reported missing victim. The victim can be identified if the characteristics such as sex, age, past medical history and so on, met the information found from the skeletal remains.




Figure 1 : Developmental stage differences between (from left to right) 6 months, 6 years, and 8 years of age



 

Figure 2: Developmental changes to the pubic symphysis, from younger (on left) to older (on right). 




Fingerprinting

Fingerprints are an individual characteristics, nobody shares the exact same fingerprint pattern, including identical twins. It will remain unchanged for life of an individual unless the prints are changed by permanents cuts or scars. Fingerprints obtained are then processed through the Integrated Automated Fingerprint Identification System (used to find possible matches with fingerprints in the database). If the fingerprint matches with the fingerprints found in the database, the victim can be identified.


Figure 3 and 4 shows different patterns of fingerprints and ridges.

 

Figure 3

Figure 4 

Methods of Fingerprint Detection:

· Argon Ion Lasers –fluorescence techniques for enhancement of chemically developed latent fingerprints

· Ninhydrin- chemical that bonds with the amino acids in fingerprints and will produce a blue or purple color. It works well on paper or cardboard surfaces.

· Cyanoacrylate fuming method (super glue method)- a procedure that is used to develop fingerprints on a variety of objects

· Magnetic powder – use to reveal latent prints and works on shiny surfaces or plastic baggies or containers.



Nuclear DNA Testing


DNA testing is one of the best methods to identify a victim or victims. For identification purpose, it is necessary to collect DNA samples from family members and from personal items or prior medical specimens to compare with the DNA from victim’s remain.

Figure 5: DNA sources(that helps to identify the victims) with different degree of usefulness.



DNA can be collected from very small amounts of blood, mouth (cheek) scrapings, hair roots, urine, semen from the body.

Nuclear DNA- Comes from the cell nucleus, is inherited by both parents. Each person’s DNA is unique except for identical twins. Can be easily damaged by heat or other conditions, hence not always available for to be used for identification. When a sufficient nuclear DNA profile from the victim’s remains matches the nuclear DNA profile from a sample known to have come from the victim, we can be very sure of the identity of the victim.



The mitochondria DNA testing

The majority of our DNA is inherited by both of our parents, which is a complete mixture of our entire ancestor. But there are two pieces of DNA which is inherited in a very simple way. One of these is the mitochondria DNA, which is pass down just through the female line, from mother to daughter and daughter down through the generation so everyone of us would have the same mitochondria DNA as our mothers, and that give us a fantastic opportunity to trace the direct relationship of a victim and to confirm the identity of a victim if there is a female direct relation of the victim. This method was used by the University of Leicester in identifying the skeleton of Richard III, the last Plantagenet King of England, where the skeleton was discovered in a council carpark in Leicester in September 2012. They isolated the mitochondrial DNA taken from the skeleton to do a test. Richard III would have had the same mitochondrial DNA as his sister Anne of York (they would have got it from their mother Cecily Neville). The University then looked for an unbroken mother daughter line from Anne of York to the present day. The University of Leicester page on Richard III confirms that they found two unbroken mother-daughter lines from Anne of York. One of the present day descendants, Michael Ibsen and his siblings all agreed to have their DNA sampled. The other present day descendant also agreed to have their DNA sampled, but they wanted to remain anonymous to the public. The DNA of the anonymous sampler matched both that of Michael Ibsen, and that of the skeleton of Richard III, which proves that they are all descended from Cecily Neville. Similarly in this case, the mitochondrial DNA can be isolated and tested with the list of missing adults and children’s female direct relation. By this, we can actually identify the victims.


Figure 8 : Nuclear DNA and Mitochondrial DNA 




Hair Analysis

Hairs are composed primarily of the protein keratin. Age of an individual cannot be determined through the hair by a microscopic examinations because the microscopic appearance of certain human hairs, such as those of infants and elderly individuals, may provide a general indication of age. Besides, some elderly still have “baby hair” on them, so it is unlikely to estimate it is an adult or infant. However, the sex of an individual can be estimated by a microscopic examinations, provided the hair is forcibly removed causing the hair follicle still attaching to it. Sex of the individual can then be estimated through the staining of sex chromatin in the cells found in the follicular tissue.

Each species of animal possesses hair with characteristic length, colour, shape, root appearance, and internal microscopic features that distinguish one animal from another. Same goes to different races of human. The race of the individual can be estimated. Negroid(African) mostly have curly or kinky hair with flattened cross section, larger pigment granules are found compared to Caucasian and Mongoloid hair, and are groups in clumps with different shapes and sizes. Caucasoid (European) mostly have straight or wavy hair and exhibit colours ranging from blonde to brown to black. They have hair shafts which vary from round to oval in cross section and have evenly distributed medium sized pigment granules. As for Mongoloid(Asian), their hair are usually coarse, straight and circular in cross section with a wider diameter than the hairs of the Negroid and Caucasian. Their cuticle(outer layer of hair) is significantly thicker than the other racial groups’ hairs. The medulla (central canal) is continuous and wide also.

In a nut shell, by using a strand of hair found in the crime scene, the sex and also the race of victim can be identified. If DNA is extracted from the follicle cells’ nucleus (if found), it can be searched in the database if there’s any similar DNA, then the victim can be identified.

Figure 7: Forcibly removed hair may have tissue attached to it



Forensic Botany

Forensic botanists look to plant life in order to gain information regarding possible crimes. Leaves, seeds and pollen found either on a body or at the scene of a crime can offer valuable information regarding the timescales of a crime and also if the body has been moved between two or more different locations. Besides, it incorporates several sub disciplines such as dendrochronology (the study of tree rings), systematics (the classification of plants), ecology and forensic palynology (the study of pollen). These can produce specific findings of location of death, decomposition and time of year.


http://www.sfu.museum/forensics/trim/s/videos/bo_role_forensic_botanist-en-VMC3_Flash_Gamma.mov



Blood Stain Analysis

The examination of the shapes, locations and distributions patterns of bloodstains in order to provide and interpretation of the physical events by which they were created that is based on the premise that all bloodstains patterns are characteristic of the forces that have created them.

The blood stain can be analysed through chemical and physical considerations. Upon exiting the body, bloodstains transit from bright red to dark brown, which is attributed to oxidation of oxy-haemoglobin (HbO2) to methaemoglobin (met-Hb) and hemichrome (HC). The fractions of HbO2, met-Hb and HC in a bloodstain can used for age determination of bloodstains and can be measured by Reflectance Spectroscopy. Once blood has left the body it behaves as fluid, gravity acts on the blood, given the right circumstances blood can act according to ballistic theory. Viscosity and surface tension of the blood can also help to determine how it behaves and lead to recreation of crime.

These are the general categories of bloodstains :

Drip Stains/Patterns

(caused by the force of gravity only)

Transfer Stains/Patterns

(a blood contaminated object(s) contacting a surface)

Spatter Patterns (impact, cast-off, etc.)

(liquid blood, internally or externally, subjected to a force greater than gravity)

Blood spatters can indicate important information such as:

• Type and velocity of weapon 
• Number of blows 
• Handedness of assailant (assailants tend to strike with their dominant hand on the opposite side of the victim's body) 
• Position and movements of the victim and assailant during and after the attack 
• Which wounds were inflicted first 
• Type of injuries 
• How long ago the crime was committed 
• Whether death was immediate or delayed 

Impression Evidence

Impressions are used to find legitimate matches and the practice works the same way as fingerprinting. There are three main types: Footprints (or shoe impressions), Tire tread impressions and Tool markings.

Impressions are left on hard surface by creating electrostatic charges. Simply sprinkling fingerprint dusting powder over recent footprints will attract powder to the charge and create visual image. However, residual static charges don’t last very long and can be easily upset so forensic experts rely more on the deformation of surface areas. Shoe impressions on materials such as soil, sand or snow can produce a largely three-dimensional footprint. While stains and other residue will leave two-dimensional marks and create a recognizable image. Tire marks are much easier to identify. Defects and wear on a tire tread caused by nails, gravel, and patches can identify a unique set of tires. Lastly, tool marks are created when a tool comes into contact with another object or surface and leaves a significant impression.

Forensic Odontology

Tooth identification

The teeth remain long after all other parts have decayed is because the tooth enamel is harder than any other substance in the human body. Enamel can withstand temperatures of more than 2000 degrees Fahrenheit. Teeth are fragile and may shrink especially through intense heat, but they can be preserved with lacquer and used for identification. Dental work (partial od gold crown) will be distorted by fire but still can aid in identification.


Bite Mark Analysis


Bite marks can be detected on the victim or the perpetrator, or on foodstuffs found at the scene of the crime, when the marks were compared to dental impressions taken. The first step in analyzing the bite is to identify it as human as animal teeth are very different. Then, forensic dentists will take measurements of each individual bite mark and record it. Bite photography must be conducted precisely, to accurately depict the orientation, depth and size of the bite. The bite marks on deceased victims are cut out from the skin and preserved in formalin. Forensic dentists then make a silicone cast of the bite mark. The movement of a person’s jaw and tougue when he or she bites contributes to the type of mark that is left. It is not typical to find bite marks with both upper and lower teeth. Forensic dentists use several different terms to describe the type of bite mark:

Abrasion - a scrape on the skinArtifact - when a piece of the body, such as an ear lobe, is removed through biting
Avulsion - a bite resulting in the removal of skin
Contusion - a bruise
Hemorrhage - a profusely bleeding bite
Incision - a clean, neat wound
Laceration - a puncture wound


The bite mark evidence

Part I: MURDER Most Brutal! Q1,2,3

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?

Forensic odontology, also known as forensic dentistry, is the study and the use of dental knowledge to deal with legal issues. It involves the proper collection, handling, examination, and evaluation of dental evidence.

Forensic odontology works on the principle that no two people have exactly the same dental imprints. Extractions, fillings, chipped, gapped, or closely spaced teeth can all be used to identify who the teeth marks are from. Some teeth may even be twisted or tilted. Even with individuals who have had their teeth straightened through the use of braces, there will be some distinctive features that can be used to identify them based on their dental work.







The most common task in forensic odontology is to identify the deceased. A specialist will be called in to compare the deceased's most recent dental records to the teeth of the corpse. If there are no dental records available, the forensic odontologist will prepare a profile of the deceased based on their teeth. The identification can be done by using dental records including radiographs, ante-mortem (prior to death) and post-mortem photographs and DNA.


Postmortem Odontogram


The forensic dentists are responsible for six main areas of practice:

• · Identification of found human remains
• · Identification in mass fatalities
• · Assessment of bite mark injuries
• · Assessment of cases of abuse (child, spousal, elder)
• · Civil cases involving malpractice 
• · Age estimation

The concept of dental identification is that postmortem dental remains can be compared with antemortem dental records, including written notes, study casts, radiographs, etc, to confirm identity. Clearly, individuals with numerous and complex dental treatments are often easier to identify than those individuals with little or no restorative treatment. The teeth not only represent a suitable repository for such unique and identifying features, they also survive most postmortem events that can disrupt or change other body tissues.

There are a few means by which a forensic dentist can use to investigate on a crime case, which includes identification of human remains, assessment of bite-mark evidences, age estimation, DNA-sampling, radiology and forensic odontology.

Identification of human remains can help in age and gender estimation, for example with the analysis of cranial and pubic suture closure, radiographic aging of the femur and articular surface, patterns of tooth eruption and tooth wear.

Bite-mark evidence is a good source to aid in the identification of criminals. The bite-marks can be picked up from either the victims or the criminals, or even food at the crime scenes. It is possible to identify specific types of teeth by their class characteristics. For example, incisors produce rectangular injuries and canines produce triangular injuries. A dental impression can be made of any suspect and be compared to the bite-marks. However, there is a significant rate of false identification using just bite-mark evidence.



The extraction of mtDNA from tooth pulps for DNA-sampling and criminal identification is one of the most commonly used and most accurate method in forensic dentistry. This is done with the use of a technique known as the nuclear DNA typing and amplification of the DNA via polymerase chain reaction (PCR). Other than the tooth pulps, DNA samples can also be acquired from the gingiva, saliva and the hair.
In radiology and forensic odontology, any bone loss, caries, crowns, fixed bridges and tooth restorations can be revealed from the radioopacity and radiolucency of the radiographs. Because of the high temperature resistance of enamel, which can hold up to 1000 degree Celsius of heat waves, tooth identification with radiographs and forensic dentistry can come in handy in devastating disasters such as air crashes or any fire accidents.


Antemortem image of frontal sinuses.



Postmortem view of the frontal sinuses in the previous image. Dehydration may have accounted for the relative clarity of the film as compared with the antemortem film in the previous image.



This radiograph of the maxillary sinus shows another site for analysis when the dentition is missing. (From the private collection of Phil Levine, DDS, Pensacola, Fla.







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


The skull has features that can determine sex, but how? At young age, the sex-related skull features are less distinct and usually more difficult to interpret. However, as they reach puberty and go through sexual maturation, the skull will become more defined and hence sex will be more detectable. It is very important in forensics investigation to differentiate the differences between male and female skull which will be discussed below.

The male and female skull are differentiated by characteristics like size, weight shape and etc. The Table 1.0 below shows the characteristics of the skull.

ps: refer to Figure 1.1 and Figure 1.2



Figure 1.1




Figure 1.2



Table 1.0


In a nutshell, the male human skull is different from a female human skull. There is a problem determining sex using skeleton remains especially when only fragments of body are found, thus, the forensic odontologist may assist other experts to determine the sex of victims by using skull and teeth. Features like morphology of the tooth and skull has important characteristics for male and female sexes. This plays a very important role in human identification in Forensic odontology by investigating the aspects of dental evidence like the skull and teeth to establish the sex of victims with bodies beyond recognition due to major mass disaster. Besides determining the sex using skeleton, age also can be determine from skull and teeth.
However, new developments like PCR amplification can accurately determine the sex of remains.

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

BUT......

So far, there is insufficient information to determine the exact number of victims. However, we are assuming that all the bony pieces found belong to one person only. That is, if all the pieces found were to be assembled, we would get one human skull.

Further excavation must be done to determine for sure if there is more than one victim. At this stage it is also not possible to determine the gender, ethnicity and age of the victim.

Over time, certain changes might occur to the remains. A depression of the skull/broken bones could indicate death due to skull fracture but again, decomposition factors such as weather, soil chemical components, scavengers and insects must be taken into consideration. Or, the chin of a female (more rounded) can be mistaken for that of a male (more square) after decay over a long period.

The age can be determined by examining bone sizes and fusions/sutures. With age, joints or fontanels also change in size. Bone loss is significant of advanced age. Bone ossification examination also helps. Teeth erupt in a certain order and that also can greatly help determine the age. Additional information comes from examining the degree of root development deep within the jawbone. If wisdom teeth are present, individual was above 18. Finally, the microscopic examination of tooth enamel can confirm the age.





Last but not least, different races have different cranial features. Nasal aperture, eye orbit shape, subnasal prognathism are some of the features that can differ.