Question 5 (Part 3): Matching the Photos of Victims with Evidences

Question 5!

Here comes the most exciting part of the investigation…to match the evidences collected with their respective victims. Although we still can’t be 100% sure whether our hypothesis is true, we are coming closer in resolving the case.

Below is the list of possible victims that might be involved in this case.

• .       Herman Hartono
• .       Adi Hartono (son of Herman Hartono)
• .       Anya Suriati (9-year old twin sister to Tanya Rosilawati)

So let us start from evidence one! As we have mentioned above in question 4, the most significant feature we can see from evidence one is the presence of third molar on both left and right side of the mandible. The shape of the skull which portrays rounded supraorbital ridge leads us to conclude that the skull belongs to a male victim. Hence, we can now say that evidence one can be the remnants of either Herman Hartono or Adi Hartono who have both reach adulthood.

Evidence 2 shows the presence of three molars on the right side of the mandible which is a distinct feature of the jaw. Besides, the angle of the mandible is more acute with a prominent gonial eversion. All these features lead to the conclusion of a male adult victim. Therefore, there are only two possible victims that we can consider, which are Herman Hartono and Adi Hartono.

Evidence 3 shows a child’s mandible with erupted mandibular canine. Due to the low resolution of the picture, we couldn’t distinguish and confirm whether the canine is a deciduous or permanent canine until a detailed study of the tooth morphology is done. However, in this case we can assume that it is a permanent canine as permanent canine erupts at the age of 9-10 years old. Besides, Anya is the only possible child victim that we have, thus we can deduce that this jaw belongs to Anya Suriati who is 9 years old.

In conclusion, the only victim that we can confidently match the evidences is Anya Suriati. Further investigations certainly need to be done to differentiate between Herman Hartono and Adi Hartono’s remnants.

Question 6: Matching the Evidence

So here comes the question before the finale, how do we match the evidences collected with the suspected victims reported missing? 

From the bone remains and skull fragments obtained by The Dental Tooth Fairies from the crime scene, DNA samples of the victims are able to be extracted and collected. After that, we are able to generate DNA fingerprints for the victims via a technique called DNA Profiling. 

(Watch the above video to get a clearer picture on DNA fingerprints and how they are generated)

* Note : All characters in this publication are fictitious and any resemblance to real persons, living or dead, is purely fictional. All photos published are credited and used solely as examples. All DNA samples are purely fictional.

Looking into Adi Hartono and Herman Hartono's case, we know that they are paternally linked. But how do we prove that? And how can we prove that the skull fragments and bone remains belong to them?


Based on the evidence found in the crime scene, we can conclude that one of the bone remains belonged to a young male adult. From the DNA sample extracted from it, we are able to create a DNA fingerprint of the young male adult, as seen below. Finally in order to confirm that the bone remains actually belonged to Adi Hartono, we make another DNA fingerprint based on any DNA samples collected from his room, such as hair, saliva, skin, blood and even semen too, or maybe even from his family doctor whom have his blood samples. If the DNA sample from the crime scene and DNA sample of Adi Hartono matches 100%, then we can conclude that the bone remains actually belonged to Adi Hartono.

Using the same method, we can do the same for the other DNA sample found on the bone remains of the male adult. Assuming the same procedures have been conducted, DNA sample of the male adult bone remains is compared with the DNA sample of the Herman Hartono. If both DNA fingerprints matches, then we can conclude that the bone remains belonged to Herman Hartono.


Ok, now to confirm whether Adi Hartono and Herman Hartono are biological father and son. As shown below, we have 3 DNA fingerprints prepared by the Dental Tooth Fairies. The extra DNA fingerprint is obtained from a DNA sample collected from Ms. Hartono (Adi Hartono's biological mother, Herman Hartono's wife).

Observe the DNA bands carefully.

From your observation, you will be able to find that some of the DNA bands from Adi match with Herman's DNA bands and the rest of Adi's DNA bands match with his biological mother, Mrs. Hartono's DNA bands. It can be concluded that all DNA bands inherited in a child's profile are inherited from his parents. Hence, we can conclude that Adi Hartono and Herman Hartono are blood related and Herman Hartono is Adi Hartono's biological father.

As we know, there was DNA profiling pattern that matched one living twin (Tanya Rosilawati). Since identical twins have almost identical DNA, we can conclude that the child’s jaw remains belong to Tanya’s twin, Anya Suriati.

How are twins formed?
During sexual intercourse, a single sperm meets a single egg. The cells divide and expand as the zygote travels to the uterus. Occasionally, for reasons unknown, the cell divides into two parts that develop as two distinct individuals, creating monozygotic twins. Technically, we consider the reason for the split as mutation.

Identical twins’ DNA varies?
Research in 2005 found that all identical twins may actually differ genetically from their partners to some degree. Geneticist Carl Bruder et al reported results of a study of nineteen identical twins. The team found relatively common, but small, differences in the DNA of these identical twins. For some twins, one twin had a different number of copies of a given gene than his twin. This condition is called 'copy number variant' or CNV.

Fun Facts about GENES!


Theoretically, identical twins develop from monozygotic cell division will share the same genetic profile. However, science and technology in this 21st century has proven it to be not quite accurate in some cases. In February 2008, geneticist Carl Bruder of the University of Alabama at Birmingham, reported results of a study of nineteen identical twins. Bruder and his team discovered relatively common, but small, differences in the DNA of these identical twins. What happens is one twin’s DNA differed from the other at various points on their genomes, i.e.one twin had a different number of copies of a given gene than his twin. This genetic state is known as 'copy number variant' or CNV.

How is it so? At first when the fertilized egg is divided into two, identical genetic profile of 100% similarity is seen. The initial divided fertilized egg will form two cells which mean at the beginning the DNA is identical. However, in order for the egg cell to form into embryo, millions or even trillions of cell division must occur. In between the process of cell division, the cells can make mistakes in the number of copies of a given gene passing to the daughter cells, which is the so-called mutation. However, such mutation could not actually being spotted upon DNA analysis. Hence, that’s how twins sometimes can reach different numbers of copies of a gene and why some identical twins’ DNA are almost identical but not fully identical.





As you can see in this picture, you can note the slight difference between each twins’ DNA profile. For individuals in B and C, you can see that there are more similarities in the DNA profiling whereas sometimes due to CNV, you can expect results in A and D.



References

http://www.livescience.com/4833-identical-twins-dna-varies.html
http://www.wonderquest.com/twins-dna.htm
http://multiples.about.com/od/funfacts/a/Identical-Twins-And-Dna.htm

Question 4: Let’s uncover the secrets hidden in bones!

So, other than identifying the victim by dental means, what other ways can the identity be revealed? In many criminal cases, forensic anthropology made an obvious contribution in identification of the victim.

Picture from www.forensicscsi.com

Anthropology is the scientific study of the origin, the behavior and the physical, social and cultural development of the humans. Forensic anthropologists are trained to identify human remains along with pathologists, homicide detectives and other specialists.

Roles of a forensic anthropologist:
1. Aids in collection and analysis of human remains
2. Identifies victims beyond recognition (normally victims are examined in the late stages of decomposition i.e. completely skeletonized)
3. Estimates time since death
4. Establishment of injuries and potentially cause of death
“Bones offer amazing clues”
Human remains may give some clues for these aspects:

-Age 
-Age of remains

-Sex
-Ethnicity
-Stature, weight and individual differences
-Facial reconstruction
-DNA

J Age J
As an individual ages, ossification (fusing of separate pieces of bone) occurs in around 800 points around the body. As the bones fuse together, sutures are formed in between them, appearing as ‘zigzag seams’. The fusion of particular bones generally occurs at specific points in an individual’s life. From here, the age of the individual can be estimated.

Bone plate
Around the age of 6, two bone plates form at either end of the radius bone in the arm. The lower bone plate fuses with the radius years later, at age 17 in males and age 20 in females. The upper bone plate follows shortly after. 

Fusing of epiphysis (rounded end of bone) to diaphysis (bone shaft)
Growth centers within the limb bones allow the limbs to lengthen for growth. Throughout this period, the epiphyses are soft, eventually hardening into bone and fusing with the main shaft as adulthood approaches. The head of the femur generally fuses at age 18-20, and part of the hip fuses at around age 24. After this point, the study of this fusing is fairly useless in age determination. 

Cranial sutures (on the skull)
At birth, the human skull is composed of numerous smaller bone segments, their division giving the skull flexibility. As the individual ages, ossification occurs. It is useful in age estimation only if the victim is <30 years old, after which ossification of skull bones is usually complete. 

Cartilage
Some sections of cartilage around the body gradually turn into bone at a particular age (e.g. the wrists). If the victim is < age of 13, a wrist x-ray can often pinpoint the child’s age. 

Pubic symphysis (the midline joint between the left and right pubic bones)
The two pubic bones, joined by cartilage, are characterized by a rough, uneven surface which gradually smoothens out over time.

Osteon counting by microscopy  
Osteons are minute tunnels within the bone housing nerves and nutrient-providing blood vessels. In general, the more osteons present in the bone, the older the victim. 

Dentures, worn teeth, signs of bone degeneration, arthritis, osteoporosis (increased bone porosity) can indicate old age. Tooth eruption date can also help in determining age, particularly in younger individuals.

J Age of remains J
The age of bones can be established by carbon dating. The radioisotope carbon-14 is taken up by humans in life. As the half-life of carbon-14 is known as being 5,700 years, the amount of the isotope remaining in the sample can be used to calculate its age. Hence, time since death can be estimated. This not only narrows down the time frame, but often also the range of suspects. However, if the remains are completely skeletonized, determining time since death based on the bones may be extremely difficult.

J Sex J
The most obvious feature that helps to differentiate between two genders is the pelvic bone. Women generally have proportionally wider pubic bones than men to allow room for a baby’s head to pass through during childbirth. In most cases a female will bear a sub-pubic angle of >90 degrees, whilst the sub-pubic angle of a male’s pubic bone will generally be <90 degrees. The use of the pelvic bone alone has proved extremely precise in establishing sex, with an accuracy of up to 95% (Byers, 2002). However, this is not a useful indicator when determining the sex of a pre-pubescent child, as the pelvic bone in girls is yet to widen, thus meaning there is a lack of sexual dimorphism between the sexes.

The skull is also beneficial in sex determination, though slightly less accurate than the pelvic bone [80-90% using the skull, according to Byers (2002)]. We had discussed about the differences between a male skull and a female skull earlier in Part 1.

Besides, males tend to have larger, heavier, and more rugged bones in general, with slightly larger ends to support stronger muscles. Sex is generally easier to establish if the racial background of the victim is known, due to differences between different ethnic groups.

J Ethnicity J
A Caucasian victim
- narrower face and high-bridged nasal bone
- flat lingual surface in upper incisors
- prominent chin and flat cheekbones

A Negroid victim
- broader nose bridge with wider nasal openings and subnasal grooves
- outward-sloping jaws
- flat lingual surface in upper incisors

A Mongoloid victim
- broader face
- squarer, forward-sloping, wing-like cheekbones
- lower nose bridge
- shovel-shaped upper incisors
- flatter skull 
The morphology of hair between different ethnicities varies. Thus, the structure and colour of any remaining hair may indicate the ethnic origin of the victim. However, the remains of mixed-race victim are likely to display signs of two ethnic groups, making the deduction of race much more difficult.

J Stature, Weight & Individual Differences J
stature identification

-if the skeleton is whole, direct measurement may be used to establish the rough height, with a few inches added to account for flesh.

-established using a formula based around the length of a long bone such as humerus or femur ( Human generally has height two and two thirds length of femur)

-approximated by a measurement from fingertip to fingertip of outstretched arm

Weight

-difficult to establish as layers of fat leave no markings on the bones. However, well developed muscles will leave markers on the bones. ( The more they are used, the rougher the bone’s surface becomes to anchor the tendons of the muscle in use)

-any clothing found worn by the victim may indicate their clothes size and so their weight.

Individual Differences

-through medical and dental records (certain diseases, previous injuries, and birth defects can all leave marks on the bones)

-body implants (artificial hips and breast implants) often hold a unique serial number

J Facial Reconstruction J
It is the method of reconstructing the living face of an individual from skeletal remains.

1.the skull is cleaned of any remaining tissue in preparation for the reconstruction.

2.A number of round, rubber markers are placed at specific points on the skull. (These landmarks are used to indicate the depth of flesh in these locations, their depth being dependent on the likes of sex, age, race, and the presumed weight of the individual.)

3.Strips of clay join these landmarks, with more clay applied in between to act as the ‘flesh’ of the face.(Facial muscles are laid over the flesh, their structures and sizes based on the shape and size of particular facial bones.)

4.External features are then added, such as eyes, ears and a nose. 

5.the skin is coloured and an appropriate hair colour and style selected. 

J DNAJ
If a forensic anthropologist has been called upon, the remains are most likely skeletonised, meaning bodily tissues have decayed. In these situations, it is highly unlikely that nuclear DNA can be extracted. However it may be possible that mitochondrial DNA can be utilised to create a DNA profile. Mitochondrial DNA, or mtDNA, is transmitted through the maternal line, meaning an individual’s mitochondrial DNA originated from their mother. Though not as valuable, mtDNA is much more resilient, and can sometimes be extracted from severely decayed corpses. 

Reference: http://forensicsciencecentral.co.uk/anthropology.shtml

Question 5 (Part 2): Possible further investigations

Question 5: Part 2 

Considering the evidences available up to this point in time, describe in detail how you would go about investigating further, assuming you are Dr. Rudi or Dr. Suria, explaining what you anticipate at each step.

After obtaining and interpreting the evidences found in the crime scene, the time has come to proceed to one of the crucial phase of the investigation, which is creating a profile for the victims by Facial Reconstruction. Many software and programs are used by Forensic Teams to put together a 'face', to help match and narrow down possibilities of victims and suspects of the case. Not only that, facial reconstruction can be done by comparison of ante and post mortem data, use of previous radio graphs and clinical photographs if any. Every person's face is unique and even identical twins have small minute distinct features to help tell them apart. 

The picture below, shows the before and after a facial reconstruction surgery! 

In the Facial Reconstruction process, several details come into play, such as 

1. age factor 
2. facial tissue depth measurement
3. hard and soft tissues of face, 
4. distinct characteristics eg: birth mark, mole and etc

The video below, tells us more about facial construction and how the process works using latest technology! 

After the victim's profile has been made, we can try to match the reconstructed face of the victim with the database and records of missing people. Other than the facial similarities, we also have to take into account of the estimated age group of the victim and the time frame at which the victim went missing, before actually ruling out any possibilities. After making a shortlist of possible victims, we could perhaps approach the suspected victim's families and relatives to get further details for reconfirmation and even detailed report for the investigation. Apart from that, we could get some DNA materials (hair, body fluids, etc) from the suspected victim's biological parents, in order to proceed to the next step, DNA Profiling via POLYMERASE CHAIN REACTION method. 

The picture below shows a simple diagram on how the mechanism of the PCR works!

The 2 picture below shows how DNA Profiling looks like with bands shown on the film.

Apart from that, from discoveries found in the evidence (presence of caries on the lower first permanent molar, as well as fissure sealant on the third molar), we are able to compare the findings with ante mortom records of dentists the suspected victim might have visited. Dental records provided by the dentist might contain information of the victim's history - physical examination, diagnosis, treatment, and the management of the victim, past medical history, family history and social history.

Question 5 (Part 1): The Evidence Presented

Question 5:

List the evidences that have been presented to both the doctors.

Picture 1: Adult's skull & jaw

Let’s look at the mandible. It bears five teeth, including three molars on the right and two molars (second and third molars) on the left. Eleven tooth sockets with missing teeth can also be clearly seen. We can thus deduce that this mandible belongs to an adult above the age of 17 due to the presence of third molars. However, we cannot predict the gender of the victim by looking at the mandible alone.

The skull here portrays rounded supraorbital ridge. It could belong to a male. Fragment of bone consisting tooth sockets is present. Further investigations need to be performed to gather more information before we jump into conclusion.

Picture 2: Pieces of a jaw

This piece of evidence shows the anterior view of a mandible bearing three molars on the right side. The other feature which we can appreciate is the angle of mandible is more acute. Besides, it displays a prominent gonial eversion of mandible. We may presume that the victim is probably a male adult.

Picture here shows the posterior view of the same piece of mandible. 

Closer look at the lower right molars! Note the presence of caries on the lower first permanent molar, as well as fissure sealant on the third molar. These bits and pieces of information are useful enough for us to look up the dental records of missing persons and see if we are lucky enough to get a match! 

Picture 3: Child's jaw

How can we tell that this mandible belongs to a child? As you can see, the mandible is smaller than that of adult. The child dentitions are incomplete because not all the teeth had fully erupted. The remarkable anterior tooth shown here could be a canine. As lower deciduous canine erupts between 17-23 months, the child should be approximately 2 years old.

The Dental Tooth Fairies

With the exponential rise of crime and disasters around the world in the era of 2013, panic and anxiety starts to hit the population of community in IMU as the amount of weird unsolved cases starts to pile up. Henceforth, the IMU committees had come up with an idea to put together a team of dental forensics who specialise in particular skills, whom will get the job done. People whom aren’t afraid to get their hands dirty and inflict fear upon crime offenders. The silent protectors, the watchful guardians of the IMU community, the Dental Tooth Fairies! So, sit back, relax and enjoy the progress of the Dental Tooth Fairies for these upcoming few weeks.

Introduction to Forensic Dentistry

Before my team and I can actually start bringing you guys to embark on this adventurous journey on how we tackle cases, first of all, we have to explain briefly the roles of a forensic dentist.

In this 21st century era, with crime rates increasing together with the advancement in science and technology, a new eye-opening world of forensic science is introduced to help solve cases which puzzle even the wisest of man. No matter how careful, smart or even experienced a criminal is, clues such fingerprints, footprints, body fluids, bones, teeth and even bite marks are always left behind. Maybe this is one way God made man to be imperfect to a certain extent that criminals will always be put behind bars.

If you choose to walk down the part of forensic dentistry with us in the future, you shall be known as a “FORENSIC ODONTOLOGIST”. Before that, we will like you to discover the important roles that you play in a forensic team as crime solving is definitely not a one man's job, and even the great Sherlock Holmes had a dear friend to help him through thick and thin.




The word 'Forensic' comes from a latin word 'Forensis' meaning with regards to having a discussion or debate. Basically, you will work as a regular dentist, but trained with high level of experience to help in identifying unknown remains and bite marks on a specific individuals. You will be called to perform forensic examinations as requested by local law enforcement or your medical colleagues of forensic pathologist, expect to be called in by police officers, medical examiner or even coroner (an officer who holds inquests in regard to violent, sudden, or unexplained deaths). Forensic odontology requires attention to collect details and the ability to work patiently so as to complete a lengthy step-by-step process without rushing.

Below are examples of cases a Forensic Odontologist will be called in:

• Identify human remains that can no longer be identified.
• Determine the source of bite mark injuries, in cases of suspected abuse, murder, rape and etc.
• Identify bodies in mass fatalities such as accidents (aeroplane crash) and natural disasters.
• Estimate the age of skeletal remains.
• Ethnicity of the victim is unknown.
• Sex identification.
• Testify in cases of dental malpractice.

Henceforth, you will be dealing with most of the cases that are related to oral cavity. Since crimes and disasters can happen at any time, you will receive “on-call” regardless of where you are and what you are doing, and you will be required to enter the area of crime scene. These investigation of crimes and mass disasters can be sometimes be emotionally disturbing, and drain even the most trained professional mentally and physically.

Otherwise, you'll have to attend the autopsy session and take photographs, measuring the skull, take dental impressions and x-rays from the remains. Besides that, you will have to compare the exemplars to those already known missing individuals and if a match is made, you are able to identify the remains. Forensic Dentistry demands for extremely fine motor skills and requires extraordinary precision as well as accuracy. Imagine a person with the mind of Sherlock Holmes, but with the hands of Michelangelo.

Apart from that, you have to write an accurate and complete detailed report to explain the procedures done and what conclusions can be made based solely on the physical evidence available. The report done will be used in court and you will be asked to explain and testify your conclusions.

Below is a video by Doctor Larry Klein regarding the job description of a Forensic Odontologist.

Question 1 (Part 1): Identification of Victims with Bite Marks

Picture adapted from www.uthealthleader.org

Forensic odontologists play a vital role in identification of victims with bite marks. As we all know, tooth is the hardest structure found in human beings. During violent assaults such as sexual assault, rape, physical abuse, and murder, teeth can be used as an effective weapon. Victims often use their teeth as a self-defensive weapon to inflict injury on assailants. On the other hand, assailants are commonly known to attack the victims by biting them intentionally due to their enraged manner, especially in the case of child abuse. Distinct bite marks has the potential to link the assailant and the victim.  

Analysis, Comparison & Identification

Picture adapted from www.nlm.nih.gov

In bite mark analysis, bite marks with unique traits are used to compare with the suspect’s teeth imprint pattern tracings. Note that the bite marks must first be established as a human bite mark by identifying specific types of teeth via their class characteristics. 

Presence of some characteristics in the injury such as rotations, malocclusions, fractures, restorations, congenital malformations and etc could facilitate the forensic dentist to analyse the bite marks. However, the overall significance of bite marks can be decreased when these features are absent in the injury. 

Forensic dentist must understand tooth morphology, dental arch characteristics, occlusions and etc thoroughly in order to carry out bite mark analysis accurately.

How are evidences collected from bite victim?

Picture adapted from www.utforensic.org

Dental forensic examiner, despite recording the documentation of physical appearance, size, orientation and location of bite marks, must take close-up photographs using intra-oral camera with a reference scale to allow following measurements. Albeit both colour and black-and-white film photography remain as the standard, digital photography are well-accepted. Subcutaneous evidence of bite mark damage can be identified by using infrared photography.

Saliva swabs (if applicable) should be collected from the bitten surface on the victim along with a DNA sample. These will later be analysed and amplified (eg: Polymerase Chain Reaction (PCR) analysis) to make comparison between the samples and bite marks, resulting in identifying association between the biter and the injury.

A precise impression of the bitten surface should be taken in order to inspect the presence of any irregularities caused by the teeth.

How are evidences collected from bite suspect?

It is necessary to perform a clinical examination on the suspect, including extra-oral and intra-oral examinations. Extensive photographs, impressions as well as bite sample should be collected for subsequent analysis. These procedures could only be done after obtaining a court-ordered search warrant.

Summary

Forensic dentistry field is still working until today to increase the scientific validity for human bite marks to provide adequate evidence for jurisprudence purpose.

Reference: http://www.forensic-dentistry.info/wp/?page_id=9

Question 1 (Part 2): Forensic Dentistry in Identification of Burnt Victims

A body that has been only partially burned can be identified through DNA fingerprinting.

But what if the body has been severely burned?

Fingerprints are not a viable option for identification anymore as the skin has burned!

This is when dental means play a key role in identification of the body.

Among human remains, teeth last longer than any body part, including bone. Even in the most severe burning, it is rare that "some fragments of dental evidence" wouldn't exist.

Comparative Dental Identification
The postmortem (after-death) dental remains can be compared with antemortem (before-death) dental records, including written notes, study casts, radiographs etc. to confirm identity. A presumptive identification usually can be made by using data from the missing persons’ database. Respective antemortem (AM) records are then obtained from the dentists of records.

The forensic dentist produces the postmortem (PM) record by careful charting, written descriptions of the dental structures and radiographs. Then, a methodical, systematic comparison can be done between the PM and AM records. Each tooth and surrounding structures are examined.


       Figure 1: Sample of Postmortem (PM) Odontogram

The following features may give some clues for the identification:
1. filled teeth with restorative material specified
2. missing teeth
3. fixed (crowns and bridges) and removable prosthesis
4. hypodontia, hyperdontia, transposition or retained teeth
5. malocclusions: mesial molar occlusion, frontal open and deep bite > 5mm, cross bite scissors bite, midline displacement, crowding and spacing
6. palatal rugae (able to sustain burns to some extent)

Similarities and discrepancies should be noted during the comparison process. There are two types of discrepancy, those that can be explained and those that cannot. Explainable discrepancies normally relate to the time elapsed between the AM and PM records. If a discrepancy is unexplainable, for example a tooth is not present on the AM record but is present on the PM record then an exclusion must be made.


Figure 2: Explainable discrepancies of AM PM comparison

When reporting dental identification, The American Board of Forensic Odontology recommends that the conclusions should be limited to the following four:
1. Positive identification: The AM and PM data match in sufficient detail, with no unexplainable discrepancies, to establish that they are from the same individual.
2. Possible identification: the AM and PM data have consistent features but, because of the quality of either the PM remains or the AM evidence, it is not possible to establish identity positively.
3. Insufficient evidence: The available information is insufficient to form the basis for a conclusion.
4. Exclusion: the AM and PM data are clearly inconsistent.

Postmortem (PM) dental profiling
In those cases where AM records are not available, and no clues to the possible identity exist, the forensic dentist provides a PM dental profile which suggests characteristics of the individual that helps to narrow the search for the AM materials. A postmortem dental profile will typically provide information on the deceased’s age, ancestry background, sex and socio-economic status. In some instances it is possible to provide additional information regarding occupation, dietary habits, habitual behaviours and occasionally on dental or systemic diseases.

If the PM profile does not elicit the tentative identity of the deceased it may be necessary to reconstruct the individual’s appearance during life. This is the responsibility of forensic artists who use the dental profile to help with the facial reproduction.

☂     References    ☂
1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3470417/
2. http://edition.cnn.com/2013/02/13/health/burned-body-id/index.html
3. http://voices.yahoo.com/forensic-science-applied-burned-victims-136748.html
4. http://www.forensic-dentistry.info/wp/?page_id=4

Question 1 (Part 3): Identification of Murder Victims

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

The theory underlying forensic odontology is that no two mouths are alike; an individual’s dentition is believed to be unique.

Death Body Identification Techniques:

Comparison of antemortem and postmortem records,
Antemortem (before death – depends on known characteristics of a missing individual) 
Postmortem (after death – depends on recovered characteristics from an unknown body)

        at the points of comparison (specific features),

(a) the number, class, and type of teeth;

(b) tooth rotation, spacing, and malposition;

(c) anomalies and general morphology;

(d) restorations and prostheses or appliance);

            (e) caries and other pathology;

            (f) endodontic treatment;

            (g) implants and surgical repairs;

            (h) bony trabecular patterns

            (i)occlusion, erosion, and attrition.

through the dental radiographs, photographs, impressions and casts.

1.Dental radiographs – accurate dental identification requires point-by-point comparison of set of intraoral radiographs, which can be made as many as 18 to 21 images, in which all points of comparison must match exactly or in which differences must be explained.

Comparison of antemortem and postmortem radiographs looking for similarities of restorations and general morphology.

A. Antemortem radiographs of the same victim demonstrate multiple dental restorations, unique root and sinus morphology, pulp chamber shape, interdental bone height, and trabecular patterns.

B. Postmortem radiographs show consistency in some restorations when compared to the antemortem radiographs, but note that several teeth have had restorations placed after the antemortem radiographs were obtained.

2.Photographs

                

                Comparison of antemortem and postmortem photographs looking for similarities in general morphology.

A. Antemortem dental photograph showing gingival clefting.

B. Postmortem photograph showing similar clefting found in the victim at autopsy. Similar dental arch form is observed as is the overall morphology of the dental coronal structure.

                3.Radiographs and Photographs

Comparison of antemortem radiographs with postmortem findings (photographs).

A. These radiographs show antemortem (top) and postmortem (bottom) radiographs of a homicide victim with orthodontic appliances in place, which are identical to actual postmortem findings (seen in B and C) and served to confirm the identity. Note also the restoration of tooth No. 10, a peg lateral that matches as well.

B. This postmortem photograph shows the orthodontic retainer in the mandibular arch as evident in the antemortem radiographs.

C. This postmortem photograph shows the orthodontic retainer in the maxillary arch as evident in the antemortem radiographs.





reference:Scheid, R.C, Weiss Gabriela. Woelfel’s Dental Anatomy: It’s Relevance to Dentistry. 8th ed. Lippincott Williams & Wilkins