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Forensic dentistry
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Forensic Odontology
FORENSIC ODONTOLOGYBy
Prof.Pervaiz A RanaDeprtment of Forensic Medicine &
Toxicology CMH Lahore Medical College
Introduction Forensic Medicine and Odontology deals with the
professional handling , examination, interpretation and presentation of medical and dental evidences that come before legal authorities
Forensic Odontology is one of the fastest emerging sub disciplines within the broader subject of dental science.
It requires special dental expertise not possessed by ordinary pathologist qualified only in medicine.
It encompasses ethical issues and events related to the claim of negligence and malpractice by dentists and paradental professionals.
Topics of today's discussion
History and status of Forensic Odontology Working of Forensic dental section Forensic Dental Anatomy Main applications Case discussion
History
66 A.D.: Lollia Paulina’s body identified Casualty ID in Revolutionary War 1849
Vienna Opera House fire Dental identification evidence first admitted
in U.S. court system
Forensic Medicine Department
The department is divided into sub divisions like record section, cold storage, autopsy section, analytical, serologic and chemical examiner, they are interlinked with a chain of custody .
Forensic Dental Anatomy
Dentition
~ 32 teeth 4 tooth types
Incisors Canines Premolars Molars
Orientation/Size
Root Structure
Incisor
crown
neck
root
crown
neck
root
Canine
Premolar
crown
neck
roots
cusps
Molarcusps
crown
neck
roots
The Universal System
Each tooth has a specific number
Each surface of the teeth are classified Notes extractions,
fillings, orientation, etc.
Primary dentition noted with upper case letters
Facial Dissection
The usual questions
Are the remains human?
If so, what are the sex, age, and race of the individual?
Who is the person?
Objective is Identification
Is it a tooth, or a portion of a tooth? Is it an animal tooth, or a human
tooth? If human, what type of tooth is it,
i.e., incisor, canine, premolar, or molar?
Is it deciduous/primary, or permanent?
Which quadrant does it come from, i.e., right upper, left lower, etc?
Some variation is developmental, i.e., the tooth in question developed abnormally.
Other variations are acquired at some time after birth. Such acquired variations can be the result of trauma erosion occupational insult dental work in a clinical setting.
Developmental abnormalities Abnormalities of eruption patterns. Abnormalities of shape (morphology).
Any given tooth can have missing features, extra features, or atypical features. This can include bent teeth, anomalies in the number of cusps or roots, abnormal enamel deposition, etc.
Abnormalities in the number of teeth. This can range from complete absence of teeth (adontia), to extra teeth, known as polydontia. Any given tooth may be absent in any given individual, a condition known as partial adontia. The presence of additional individual teeth is sometimes known as supernumerary teeth.
More developmental abnormalities
Abnormalities in the spacing or position of teeth. Teeth can be crowded, have gaps (diastema) between them, or be rotated or misaligned. Long-term bulimics often have the appearance of teeth that are spreading apart – as the space between the teeth increases over time..
Abnormalities in the size of teeth. It is quite rare to have abnormally small (microdontia), or abnormally large teeth (macrodontia) – either as a complete set, or individually.
Acquired abnormalities
Repairs, restorations, prostheses Dental staining & enamel variation
Coffee, colas, nicotine Erosion Occupational Health-related issues Diet composition
Occlusal attrition Missing teeth
Premortem vs. peri/postmortem
Traumatic injuries should be assessed to determine whether the injury is compatible with the explanation, and whether there is evidence of earlier trauma
Main Applications
Individual Identification Mass Disaster
Identification Bite mark Analysis
Standard Identification proceduresStandard Identification procedures
FingerprintsFingerprints
Dental recordsDental recordsPhotoPhoto
CUYAHOGA COUNTY CORONER‘S OFFICE
07-0000
Identification
Postmortem description is generated Radiographs taken
Possible identities known? Yes: Comparison to
antemortem data Match strength
determined No: Biological profile
generated
Identification
Postmortem description is generatedRadiographs taken
Possible identities known?Yes: Comparison to antemortem
data Match strength determined
No: Biological profile generated
Age Determination
Age Determination Chart
Blood Grouping
DNA profile generation
Mass Disaster Identification
Completed in the same manner as individual identification
Organization of antemortem and postmortem data is essential
Large scale problems can occur if no record available (radiological, DNA)
Mass Disaster Dental ID Teams
Postmortem Team Generates dental profile and radiographs
Antemortem Team Collects/organizes antemortem data
Records Comparison Team Compares postmortem and antemortem data
Bite mark analysis
Can be used to link a suspect to a crime
Impressions left on food, skin or other items left at a scene
Various Bite Marks
Forensic ScienceForensic Science“Every contact leaves
it’s trace”
Said professor Edmond Locard (1877), founder and director of the institute of
Criminalistics, University of Lyons, France
Impression Variation
Each dentition can produce variable impressions
Change based on pressure and surface of contact
Impressions from the same dentition
Analysis
Bite marks are photographed with a scale Bite marks on skin are taken over repeated
intervals Casts of impression are taken Impression traced onto transparencies Casts of suspects teeth are taken Comparison between suspect cast and
bite mark
Serological examination
Assailants Saliva Collection preservation & dispatch of saliva collected from bite site DNA profiling & Blood Grouping
Computer Aided Forensic Odontology
3D Bite mark analysis Automatic dental code matching OdontoSearch Automatic dental identification system
Bite mark Analysis Using 3D Scans -- DentalPrint
3D scans of dental casts are used to generate overlays using various pressure and deviation.
Bitemark Analysis Using 3D Scans-- DentalPrint
The overlays are compared with the photograph of the bite marks.
Matching Using Dental Codes- CAPMI / WinID
OdontoSearch
Different people may have the same dental codes
In the past, the strength of a match between a PM dental code and an AM dental code is based on the clinical experience of the dentist
OdontoSearch provides an objective means of assessing the frequency of occurrence for a dental code
OdontoSearch
Automatic Dental Identification System
Genuine image has a smaller matching distance than the imposter image. Images with smaller distance are included in the candidate list.
Query Image
Genuine Matching Distance = 4.22
Imposter
Matching Distance = 27.57
System Architecture
Feature Extraction
Retrieval
Atlas Registration
1 2 3 4 5 6 7 8 9 1011 1213 14 15 16
32 31 30 29 28 272625 2423222120 19 18 17
Matching
Dental Programs National Dental Program
In 1997, The Criminal Justice Information Services Division (CJIS) of the FBI created a dental task force (DTF).
State Dental Program Three states: Maryland, Washington, and California Best Collectors of Dental Records (>10%)
Famous Cases
Bite mark analysis Identification Serological analysis of bite
mark
Cases – Ted Bundy
The most famous bite mark case
The bite mark was on the body of a victim
Wax bite exemplar
Transparent overlays superimposed
Ted Bundy, was an American serial killer who murdered numerous young women between 1974 and 1978.
He confessed to 30 murders, however the total amount of victims remains unknown. He would bludgeon his victims, then strangle them to death. He engaged in rape and necrophilia.
Case# 2
in summer 1997 In a small town near yarkshaire wooden house catches fire and collapse, 2 bodies were found, remains were intermingled .
Bodies were identified as 14 years old girl And 40 years old lady anatomical features and dental record.
Cases – 9/11
•At ground zero, among 973 victims identified in the first year (with only one method), about 20% of victims were identified using dental records.
Cases – Asian Tsunami“Around mid-March, (of some 800+ identified bodies) 90% were identified by dental records …
If you post pictures of your loved ones on the bulleting boards/web boards, choose picture with a broad smile so that front teeth can be seen. A better approach is to post dental X-ray films and leave email/phone number of the dentist.”
----- Tsunami Relief website A forensic expert examines a film of the
teeth of a tsunami victim in Phuket of Thailand, on Jan. 11, 2005.
Case#3
A bite mark was identified and preserved impression was obtained reconstruction of assailants teeth was done Impression was compared with the record of
suspects and finally the assailant was arrested .
Outlines of incisal surfaces of the anterior teeth on a dental stonestudy model. Note blackened occlusal surface of posterior right molars to insure proper alignment when using finished overlays.
State of Indiana v. Jeffery Jones
Indianapolis Police Department
case no. 5610144G
History
A naked dead body of 38 years old lady was found near garbage container near her residence.
Crime scene investigators (CSI) closely analyze the body and found a bite mark on her neck and left breast.
Saliva sample was collected from bite mark
Sample send for DNA profile analysis .
C O D I SConclusion:
The DNA profile obtained from Item (s) M16 and M17 does not match the DNA profile of Item S1 and could not have originated from their initial suspect, Michael Willey.
C O D I SConclusion:
The DNA profile obtained from Item(s) M16 and M17 was searched in the Indiana DNA Database and was found to be consistent with the convicted offender sample of Jeffery Jones (DOC inmate #974912).
C O D I SConclusion:
In the absence of an identical twin, Jeffery Jones is the source of the DNA obtained from Items M16 and M17 to a reasonable degree of scientific
certainty.
FORENSIC ODONTOLOGYTHANK YOU