Lecture 6 - Disaster Victim Identification and Forensic odontology Flashcards
What do forensic dentists do?
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 or elder)
Living or deceased
Civil cases involving malpractice
Not as big in NZ, internationally big
Age estimation
Particularly in Europe, and specifically cases that involved illegal immigration
When does dental identification assume a primary role …
Dental identification assumes a primary role in the iden- tification of remains when postmortem changes, traumatic tissue injury or lack of a fingerprint record invalidate the use of visual or fingerprint methods. The identification of dental remains is of primary importance when the deceased person is skeletonized, decomposed, burned or dismem- bered.
dental record =
The dental record is a legal document owned by the dentist, and contains subjective and objective information about the patient.
Observations such as distinctive shapes of restoration, root canal treatment, buried root tips, bases under restorations, tooth and root morphology, and sinus and jawbone patterns can be identi- fied only by examination of radiographs.
bite mark pattern is compared with the
dental characteristics of the dentition of a suspect.
animal bites vs human bite marks
Animal bites often cause shear rather than impact injuries, producing lacerations of the skin and open wounds
Three reasons why you look at teeth …
unique
durable
historical record
Why teeth? - unique
dentition & teeth specific to an individual
32 teeth x 5 surfaces=160 unique surfaces
“Combined with restorative treatment, root anatomy and surrounding tissues, there are 2.5 billion possibilities in producing a dental formula”
Five surfaces including the top so lots of unique features
People often have either natural processes, disease or artificial things done by practitioners to those surfaces which changes them permanently and when you combine this with the shapes of the root and the surrounding anatomy then you can end up with a lot of possibilities, not quite as many as DNA but still enough to make it pretty unique to an individual
Why teeth? - durable
Teeth are the last tissue to disintegrate
Teeth are very hard things
Remain intact in temps up to 1600°C
Can survive significant heat exposure
Last to be decomposed
About the last thing to decompose depending on the conditions they are found in such as the acidity of soil
DNA recovery from pulp ”secluded space”
In some cases are asked to retrieve the nerve or pulp from inside the teeth which is soft tissue, it is a secluded space and it is relatively protected from heat and decomposition but difficult to get access to
Why teeth? - historical record
Most likely to have extant ante-mortem data
Permanent changes (eg:extractions) cannot be reversed
Anthropological indication of ethnicity
Identification only works if you can gather information from the deceased AND if you have antemortem data that you can reliably compare it to
number of unique surfaces on teeth
32 teeth x 5 surfaces=160 unique surfaces
forensic odontology =
Forensic odontology is the application of the science of dentistry to the field of law
Forensic odontology involves people who train clinically to do one job but actually are involved in a completely different area, it is a sub specialisation
What they do interacts with the legal system
Forensic odontologist roles include…
identification of unknown remains,
bite mark comparison,
interpretation of oral injury,
dental malpractice.
bite mark comparison …
Bite mark comparison is often used in criminal prosecutions, Bite mark comparison is the most likely to involve the criminal justice system, it is the most contentious one
Bite marks may be apparent on the victims skin or may be present on a variety of inanimate objects
Bite marks are potentially important as evidence because it may be possible, in some cases, to make a match between them and the teeth of a suspect
Individuality features of teeth include gaps between teeth, ridges on their biting edges, their relative positions within the mouth and whether any of the teeth are rotated, missing or broken. Analysis and comparisons are the realm of the forensic odontologists
Initial stage in the preservation of bite marks is to take photos using oblique lighting, if bite marks are sufficiently deep then this is usually followed by casting in an appropriate medium, make cast of suspects teeth, use computer technology to improve accuracy and use it to produce a detailed outline of the biting edges
Recovery of saliva from the vicinity of the victim’s injuries may lead to confirmation of the attackers identity through DNA profiling
DVI vs criminal forensics
Differential though may overlap
Victim of crime vs accidental death or suicide
Coronial court vs Criminal court
Coroner court = inquisitorial
Criminal court = each side presents their case and tries to discredit the other side and witnesses are cross examined
Circumstances of death vs Guilt / innocence
Forensic odontology and criminal forensics
Bite mark analysis
Maxillofacial trauma including GSW –> Injuries found in the head and neck region may be analysed by forensic odontology
Age estimation
Teeth from crime scene
Forensic odontology useful when the
person cannot be identified visually therefore asked to confirm identity using dental records
Why do you need to identify the victim?
So that those who are left behind have some explanation of what took place and if possible can get the remains of their loved ones back
Bodies change from being recognisable to unrecognisable very quickly, in some cases in a matter of a few days when it then becomes impossible to visually recognise someone
4Cs = certainty, closure, criminality, cash
Certainty
accidental victim substitution (Erebus)
correct remains returned to relatives
Closure
location & nature of death
begin grieving process
Closure on a personal level, but also on medicolegal level for wills etc
Criminality
Gunshot/explosives residue, location of victim
Cash
Medico-legal requirement for wills / insurance / business affairs
Interpol DVI guide - primary methods of identification
Fingerprint analysis
Forensic dental analysis
DNA analysis
Interpol DVI guide - secondary methods of identification
(these are other things that will support the primary identification methods)
Personal descriptions and medical findings
Evidence/clothing
Forensic odontology practitioners must be knowledgeable in …
dental anatomy,
orofacial growth and development (tooth development and eruption)
dental treatment and materials,
Need to know this so that you can identify it in the victim but also need to be able to read forensically antemortem dental records
dental biomechanics,
dental radiography,
maxillofacial osteology
Need to know the bones of the face
Forensic odontology is ______ analysis
pattern
Patterns that forensic odontologists need to be able to analyse
Identify individual teeth
Bite problems - Also called malocclusions and the problem classifications include Healthy, overly crowded, overbite, underbite
Patterns of tooth eruption - age estimation
Age estimation more useful for young people, useful up to about age 17-18 after which it doesn’t really become useful again until the opposite end of the spectrum where maybe the loss of teeth provides some distinguishable features
Primarily age estimation is particularly useful for young people and this can be quite important because you are less likely to find fillings, dental treatment, extractions, restorations, and are less likely to find records particular\ly for young victims but what you might have is a pattern of eruption that at least provides you with supporting evidence for the age of the victim
Distinguish between human and animal bites
Match a bite to a bite mark
Match a bite to a person
Recognise dental restorative materials and restorations
Hard to recognise white plastic fillings, compared to the metallic ones such as gold, doesn’t really come up on X-ray and hard to distinguish visually
Dental radiographs - patterns
Recognise patterns using written documentation of dental treatment
Antemortem records need to be analysed, usually full of shorthand and jargon
Need to translate records to a language that all dentists and a layperson can understand
Reconciliation dental sheets show antemortem and postmortem records compared side by side
Needs to be able to be presented to coroner on specific paperwork
Forensic odontology teams
Forensic Odontology is carried out by teams
The head of the team must be a qualified and registered dentist and who also has credentials as a forensic dentist, however the team itself can be made up of other dental professionals such as hygienists etc
Frequently include practitioners with auxiliary status (hygienists, therapists, technicians)
Two Forensic Odontologists (qualified dentists) must attend each case.
Allows for cross checking
One FO must have full accreditation with the NZSFO
why does forensic odontology work?
Teeth are hardest structures in body
Teeth survive high temperatures up to 1200°C
Filling materials present after 600 – 800°C (fillings often fall out before the teeth so the teeth still remain)
Resistant to decomposition and trauma
Patterns of tooth eruption allow age estimation
Tooth morphology and eruption may indicate ethnicity
See some estimations of ethnicity
Patterns of eruption, extraction, and restoration (fillings) are distinctive to individual
Root form and “smile analysis” as secondary dental identifiers
Look on social media for pictures with smile to clarify
Teeth = secluded environment for DNA recovery after fire (<500°C) and terrestrial decomposition, but not marine decomposition
Forensic odontology is a _____ ______ _____
scientific evidential process
Forensic odontology is a scientific evidential process….
Scientific: logical protocol, independent of bias (this is why you have a second person verifying what you are doing), validated reproducible techniques, peer-reviewed.
Police sometimes call them in to confirm someones identity which is not actually their job because their job is to actually collect the evidence and make a decision rather than confirm anything
Evidential: chain of custody (ensure that the evidence can be traced), recording and documentation, avoid contaminating evidence, communication understood by lay people.
Process: logical steps, independent verification and quality assurance.
Forensic odontology is a scientific evidential process - SCIENTIFIC
Scientific: logical protocol, independent of bias (this is why you have a second person verifying what you are doing), validated reproducible techniques, peer-reviewed.
Police sometimes call them in to confirm someones identity which is not actually their job because their job is to actually collect the evidence and make a decision rather than confirm anything
Forensic odontology is a scientific evidential process - EVIDENTIAL
Evidential: chain of custody (ensure that the evidence can be traced), recording and documentation, avoid contaminating evidence, communication understood by lay people.
Forensic odontology is a scientific evidential process - PROCESS
Process: logical steps, independent verification and quality assurance.
primary identifiers need
antemortem comparators
Antemortem comparators of primary identifiers …
Visual–relatives,Facebook
Fingerprints–home, criminal, military
In NZ there is not much of a record for it because it is not as routine as overseas
Dental-dentist
Rely on dentists for written records or X-rays and in the best case scenario you get both
Medical– medical records
DNA– home, relatives
Identification process using dental steps
examination and charting –> antemortem –> postmortem –> reconciliation –> reporting
Need to collect antemortem data which the police generally does and then forensic odontologists need to interpret it, forensic odontologists do postmortem and then need to reconcile and put the two together and form a process and then report on it
postmortem interpol form colour =
pink
antemortem interpol form colour =
yellow
Dental Interpol forms …
There is a missing person and a dead person form for dental records/analysis to be filled out on
On the dental forms you note what is there and what is not there, fillings present for postmortem and then doing the same with antemortem data and then reconciling the two together
Documenting forensic odontology …
Pink …
PM: Examination and recording of all missing, damaged, decayed, impacted and filled teeth.
Filling location (tooth surfaces) and material can be unique.
Recording onto Interpol “Pink” F1 & F2
Yellow…
AM: Retrieval and interpretation of antemortem records & xray films
Recording onto Interpol “Yellow” F1 & F2
Green…
For DVI, transfer data to PLASS DATA software
No colour…
RECON: Dental radiographic films may allow match to AM films.
“Smile” photography may be of some assistance
Radiography in forensic odontology
Antemortem records and X-ray films
Can get mislabelled or unlabelled records which prove problematic
Portable X-rays are $26000 and are used to take the postmortem X-ray films to compare to the antemortem X-ray films
Training for forensic odontology
already a registered dentists, also requires regular involvement in coronial victim identification i.e. you should eb regularly involved in victim identification in your own area
What are you looking for when inspecting postmortem and antemortem dental records ?
Look for points of cordance - Look for shapes that look the same, hard to reproduce exact shapes so it is good evidence to use to convince the coroner that it is that person
Account for differences - Not always on X-ray records, other stuff can be done subsequently to the X-rays that forensic odontologists have access to
Issues faced in dental examination due to deceased victims for forensic odontologists
personal protection
lightning
access and visibility
Forensic odontologists also do _____ and _____ work
military and anthropological
Lockerbie 1988
no DNA
86% identified solely or with the aid of dental –> shows how powerful and useful it is
Tangiwai disaster 1953
13 of the 22 victims buried in the common grave were identified using dental records (they were unable to be identified visually)
Mount Erebus 1979
142 (66%) of IDs were done by dental means –> dental records in a forensic setting are very useful for victim identification
Boxing Day tsunami 2004 (Indian Ocean)
No dental identification without antemortem records!
Dental indenificathion had ,little effectiveness for asian countries (therefore not useful for Thai citizens)
Use all identification techniques because one may not work/takes longer/isn’t possible to do, may give results in different time, you can map the effectiveness of the identification techniques over time and in looking at this timeline relatively early on you can see that dental identification was really good early on for identification of body
Along the timeline you see dental records being important early on and then you run out of antemortem records so you start to rely more on fingerprints and then over time DNA became really important, so all of these methods are really important but they may give results at different times in the time course of the DVI operation
Operation earthquake - 22 February 2011 12:51pm Christchurch
Two layers of security
Logistics - protection, biological hazard, suitable physical location
cultural and spiritual sensitivity
work flow established
Temporary mortuary established at military camp
Dental victim identification procedures
based on Interpol guidelines with 5 recognised phases
Phase 1 (the scene), phase 2 (post mortem), phase 3 (antemortem), phase 4 (reconciliation), phase 5 (debrief)
Phase 1: The Scene
- Crime scene, recording
- Remains labeled, recovered, transported to mortuary
- Forensic dentally-qualified and rescue- qualified person needs to be present
Phase 2: Post Mortem - Personnel - Information - Operational command and control Logistics
Five stages of post mortem ID used in Operation Earthquake
- Property - usually cleaned first then photographed and linked to the owner
- Pathology
- Dental - Nomad portable digital xray unit, Digital radiographs , False teeth - useful if labelled, Specialists from other countries flew in to aid in the identification efforts of NZ
- Fingerprints - and footprints were examined
- Quality Management - look at paperwork and ensure that it is done correctly and to a high enough standard
Summary of CHCH earthquake DVI
Involved 34 Forensic Odontologists, including five overseas dentists
> 400 working days
Considerable assistance provided by
dental technicians, dental hygienists and dental therapists
dental auxiliaries (assistants/nurses)
177 of 181 deceased were identified (98%)
Includes 70 foreign victims
94% of ID based on single or multiple primary identifiers
6% based on secondaries (property, visual/physical, circumstantial)
43% by fingerprints, 33% by dental, 4% by DNA, 14% combination.
Dental and DNA significantly more useful for fragmented remains
How to become a forensic odontologist
Forensic Odontologists are qualified dentists
FO Auxiliaries are qualified in an oral health related field
Lead FO fully credentialed with New Zealand Society of Forensic Odontology (NZSFO)
Scope of Practice defined by experience & CPD
