Forensics Flashcards
What are 3 essential characteristics of the human dentition which give them a certain uniqueness
Genetic racial characteristics
Chemical and structural modifications resulting from disease processes
Dental treatment
What are the 2 types of victim identification
Comparative identification
and
Post-mortem dental profiling
What is Comparative identification?
Used to establish that the remains of a decadent and a person represented by antemortem dental records are the same individual.
What is Postmortem dental profiling?
Cases where antemortem records are not available and no clues to the possible identity exists
In Comparative identification there are 2 types of discrepancies
Explainable discrepancies
Unexplainable discrepancies
What is the differance between explainable and unexplainable
Relate to the time elapsed between antemortem and post mortem - explainable
unexplainable - Tooth is not present on the antemortem record but present on postmortem record
What are the 4 possible conclusions of comparative identification
Positive Identification ( no discrepancies )
Possible Identification ( antep + postp consistent features - but 100% positivity can not be reached due to quality of records or antp evidence )
Insufficent evidence ( not enough of info to form basis for a conclusion )
Exclusion (ante p and post p are clearly inconsistent)
What are a few problems with dental identification?
Absence of antemortem records
Absence of acquired dental traits for identification
Poor quality dental records
Not all teeth recovered in postmortem situation
Fire can result in irreversible changes to restorations and teeth
What is postmortem dental profiling?
Used when there are no antemortem records and other methods of identification are not possible, The forensic odontologist can assist in limiting the population pool and thus increase the likelihood of locating antemortem dental records
what type of information can postmortem dental profiling provide?
The deceased age
Ancestry background
Sex
Socio-economic status
How does postmortem dental profiling assist in sex determination?
Microscopic examination of teeth can confirm sex by the presence or abscence of Y-chromatin and DNA analysis.
- Amelogenin is major matrix protein secreted by ameloblasts
- Females have 2 identical AMEL genes
- Males @ non-identical genes
What are some other methods of dental identification?
Denture/appliance labeling
DNA identification
Dental materials ( addition of kevlar fibers ) this method requires good dental records
Ruguscopy - study of palatal rugae patterns
What are the 2 types od DNA identification
Genomic and mitochodrial
Genomic - from nucleus of each cell
commonly used on forensics cases
Mitochondrial - Maternally inherited
there is a high number of copies of each cell due to high number of mitochondria present in most cells
Advantages od denture labeling
- Identify unknown denture wearers in cases involving amnesia or senility, psychiatric cases
- In cases of lost and found
- To provide a rapid and accurate method of identification where fingerprinting is not possible
- In dental laboratories and clinical practices where dentists and technicians can easily identify a marked denture
What are the 4 types of denture markings?
Engraving
Scribing
Writing
Inclusion
What are a few guidelines with regard to denture markings?
Denture strength must not be compromised
Markings must withstand fire
Markings must be visible and durable
It must be easy , efficient and inexpensive
Dental Age estimation uses what 4 diagnostic methods to examine age-related changes in teeth
Mophologic, histologic, radiographic, biochemical.
Name a radiographic method for age estimation
Atlas style chart by Schour and Massler.
Schour and Hoffman found that the pattern of what under normal conditions followed a reliable sequence of growth.
Calcification of dentition
What is the Atlas style chart by Schour and Massler?
A summary of the development of the human dentition consisting of 21 diagrams with an age range from 5 months in utero to 35 years
Advantages and disadvantages of the atlas style chart by Schour and Massler
Advs
- Simple system to follow
- Required no major specialised training
- Made use of readily available diagnostic aids
Disadvs
- Atlas Based system are based on the premise of ‘ one size fits all ‘
Name 3 other radiographic methods
Moorees
Demirjan
Ubelakers dental chart
What is the main advantage AlQatani revision of moorrees system.
Availability of diagrams for each year of development from ages 1 to 23
The histological method of age estimation is based on what morphological and histological changes of the tooth. ( Gustafson Method )
- Amount of occlusal attrition
- Loss of periodontal attachment
- Deposition of Secondary Dentine
- Cemental apposition at the root apex
- Root resorption at the apex
- Dentine translucency
What are some limitations of Gustafsons Method?
- None of the variables could be used alone expect dentine translucency
- Training in histology is problematic
- Require special equipment
- When only tooth is used the age range is increased
- Age range also increased in teeth over 50 years of age
What is a Bitemark?
It represents a pattern of injury or makring produced by teeth during the biting process
What 3 characteristics are involved in bite mark analysis?
Gross characteristics ( human or animal )
Individual characteristics ( size of tooth, rotated teeth )
Accidental characteristics ( chips and imperfections caused by attrition, abrasion and trauma )
How can a bitemark be identified?
Gross features
- Circular/elliptical
- Central are of ecchymosis – because of sucking action )
Class features
- Incisor = Rectangular mark
- Canine = Triangular mark
- Premolar/Molar = Spherical/pointed
What are the 4 methods of bitemark analysis?
- Direct macroscopic and microscopic comparative analysis ( mnost accurate and feasible bite mark analysis )
- Various overlay techniques
- Computer- generated comparisons
- 3D computer-assited programs
Analysis sequence of bitemarks?
Recognition ( human or animal bitemark )
Documentation ( photogaphy )
Evidence collection and preservation ( DNA swabs and impressions )
Physical dental profiling of evidence ( bitemark )
Physical dental profiling of the known evidence ( suspect )
Compare evidence and suspect data
Drafting of report and submission
What are a few drawbacks of bitemark analysis?
Parameters - Quality of patterns, type and quantity of material available for analysis, presence of recognisable dental features, variations of bite marks
skin is highly variable in terms of anatomical location and highly visco-elastic
Risk factors contributing child abuse?
Stress
Unemployment
Poverty
Overcrowded living spaces
Substance abuse
What are some extra-oral signs of physical abuse?
Bruising
- Cheek is the most traumatized
Burns
- Electrical, thermal or chemical
- Burns inflicted using cigarettes
Bitemarks
Intra-oral signs of Physical abuse?
Soft tissue trauma
- Injuries may occur on the tongue, lips, hard or soft palates, mucosa, frenum, gingiva
Hard Tissue trauma
- Severe trauma to the lower face may loosen teeth, completely displace them, and cause fractures of the teeth
- Discoloured teeth, indicating pulpal necrosis
- Fractures of the mandible, maxilla and other cranial bones can also be found in cases of child abuse
what are some indications of sexual abuse Intra-orally?
Gonorrhea, Syphilis, Chlamydia, Human Papilloma Virus and Human Immunodeficiency Virus.
What is the type of child neglect dentists focus on?
Medical care neglect - Dental neglect
What are the signs of Dental Neglect
Poor oral hygiene
Periodontal disease
Halitosis
Early childhood caries
Odontogenic infections
Apthous lesion due to nutritional deficiency
