49075554 forensic-odontology-dr-rizwan

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