Lecture 5 and 6 - Forensic Odontology Flashcards
What are 3 things odontologists investigate?
- Identification
- Oro-facial trauma
- Dental issues
What are the 3 principles of identification?
- Unique (Each human being is unique)
- Macroscopic or microscopic (details are required to individualize)
- Monozygotic twins can be distinguished
What are 2 traditional methods of identification?
- Visual (viewing of the deceased by family or friends)
- Property (presence of ID, registered vehicle)
What are 4 scientific methods of identification?
- Fingerprints
- Medical (implants etc)
- Dental
- DNA
What does odontology rely on?
Pattern recognition and matching
What is the overall result of odontolgy dependant on?
- Value of pattern
- Skills of examiner
What does odontology require?
Team approach for quality control and validation
What techniques does odontology use?
All techniques from visual to DNA
How is value of pattern determined?
- Amount of detail
- Rate of occurrence (of features present in a population)
When is visual identification not possible?
- Incineration
- Decomposition
- Facial trauma
- Skeletonization
- Multiple fatalities
Why teeth and dental identification?
- Individual patterns (everyone’s teeth are different)
- Introduced artefacts (dental treatment like fillings)
- Resist destruction
- Dental data
What are 3 dental limitations to identificaiton?
- Lack of searchable database: location of records
- Insufficient detail
- Lack of statistics
Why might there be lack of searchable database? (dental limitations)
- Long time since dentist visit
- Records kept for limited time, destroyed afterwards
- Family may be unaware of which dentist was seen
Why might there be insufficient detail? (dental limitations)
- No dental treatment, lack of distinctive feature
- Limited record keeping by dentists (antemortem)
- Not recovered well teeth (postmortem)
Why might there be lack of statistics? (dental limitations)
- No information (re frequencies of occurrence of features or the relationship of features to each other)
What is the summary of procedure for odontologists in Australia?
- Incident occurs
- Scene attendance (if required)
- Search for antemortem records by police
- Postmortem examination of remains
- Collate and transcribe antemortem records
- Compare postmortem and antemortem information
- Reconcile discrepancies
- Conclusion and report
What are some difficulties collecting dental data?
- Deceased beneath collapsed structures
- Commingling with other individuals and pets
- Fragile remains
- Knowing what to look for (dislodged crowns, fillings and roots)
What are some possible sources of antemortem dental data?
- Home
- Family
- Dentist referring to latest dentist
- Doctor
What is a common way antemortem dental data is recorded?
- Written notes
- Dental charts
- Photos
- X rays
- Dental appliances (dentures etc)
- Stone model
- Medical images
- Photos for social media
What is the aim for postmortem dental examination?
Record all possible information about the dentition, while maintaining respect for the deceased and their family
What are some considerations for postmortem dental examination?
- Need for good access and vision
- Increasing use of tooth-coloured restorations, which are often difficult to see or to determine the extent of coverage
- Better education has led to less restorative work increasing the reliance on anatomical and morphological features
What is another postmortem procedure?
DNA collection (tooth)
How is DNA collection of the tooth carried out?
- Healthy Molar teeth preferred or as directed by FSSA biology
- Use sterile gloves and instruments, facemask and hair net to avoid surface contamination
- Place in sealed, labeled screw-top specimen jar and arrange for delivery to forensic biology
- If skeletal material, may need to remove buccal and lingual bone to allow extraction without breaking roots
What is reconciliation?
Comparing of postmortem and antemortem details
How is reconciliation carried out?
- Charting
- Casts
- Photographs
- Radiographs
What to consider when reconciling?
- Always look to exclude (are there any features that you can not reconcile between AM and PM)
- Anatomical features
- Morphological features (crown and root shape and size)
What areas could be looked at to exclude when reconciling?
- Tooth number
- Restorations (position, shape, material, pins)
What part of the tooth is more fragile and more likely to get destroyed?
Crown of the teeth (more fragile than root)
What are possible results of reconciliation after all features have been compared?
- Unable to be reconciled (elimination)
- Concordant (match)
- Able to be reconciled (possible match)
- Not available in both data sets (non-informative)
When will a tooth have a greater weight?
When it has highly unusual features
What are 6 possible causes of discrepant (different) features?
- Lack of data (AM records, PM damage)
- Growth and development
- Progress of dental disease
- Further treatment since last recorded
- Debonding of adhesive restorations
- Charting error (nomenclature)
What are the 5 concluding interpol codes?
- Established identification
- Probable identification
- Possible identification
- Insufficient evidence
- Exclusion
Interpol code: What does established identification mean?
The postmortem and antemortem data match in sufficient detail to establish that they are from the same individual, there are no irreconcilable discrepancies
Interpol code: What does probable identification mean?
Specific characteristics correspond between PM and AM data but are both limited
Interpol code: What does possible identification mean?
There is nothing that excludes the identity but PM or AM data are both minimal
Interpol code: What does insufficient evidence mean?
The available information is insufficient to form the basis for a conclusion
Interpol code: What does exclusion mean?
The PM and AM data are clearly inconsistent
What are some pattern injuries?
- Human bite injury (on humans, objects)
- Animal bite injury (on human AM or PM, other animals, objects)
When do human bites often happen?
- Assaults
- Sexual assaults
- Child abuse
- Offensive/defensive
What are possible outcomes of observing bite marks?
- Variable (unpredictable presentation)
- No definitive attribution
- May eliminate a suspect
- May corroborate or negate victim statement
- Species identification
(bite marks are not the most useful for victim identification)
What 5 disasters were talked about?
- Bali
- Boxing day tsunami
- Victorian bushfires
- Black Saturday
- Malaysian airlines MH17
As the years went on and disasters happened, the equipment and setup for victim identification and forensic odontology improved
