33.forensic

Forensic

Odontology

An Introduction to

Forensic Dentistry

D. Caroline Mohamed 1

D C A R O L I N E M O H A M E D

Objectives:

Students should be able to explain and

discuss:

o Definition of forensic dentistry

o Responsibility of forensic dentists

o Training for forensic odontology

o History of forensic odontology

o Bite marks

o Cases

o Computer aided forensic odontology


Forensic Odontology The British Association for Forensic-Odontology

(BAFO) notes that forensic odontology is a branch of

forensic medicine and, in the interests of justice, deals

with the proper examination, handling and

presentation of dental evidence in a court of law.


• 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.


• To assist with forensic dentistry, dental

professionals need to

be aware of the importance of

keeping accurate,

current, detailed

and legible

dental records for the use of

identification.


Who practices Forensic Odontology and what do

they do?

Forensic

Odontologists

• Must have DDS

degree

• Should have

specialized

training in the

field.


Top: Forensic Odontologist analyzing animal teeth for comparison. Side: Seal for American Board of Forensic Odontology.

Responsibility of forensic odontology

1. Identification of found human remains

2. Identification in mass fatalities

3. Assessment of bite mark injuries

4. Assessment of cases of abuse (child,

spousal, elder)

5. Civil cases involving malpractice

6. Age estimation


History

• 66 A.D.: Lollia Paulina’s body identified

• Casualty ID in Revolutionary War

• 1849

o Vienna Opera House fire

o Dental identification evidence first

admitted in U.S. court system


• It was used on Adolf Hitler and Eva Braun at the end of

World War II, the New York City World Trade Center

bombing, the Waco Branch Davidien siege, and

numerous airplane crashes and natural disasters.

Different situations for

identification 1. Disfigured bodies of victims of violent crimes, fires,

motor vehicle accidents and work place accidents.

2. Persons deceased for long time or on water.

3. Mass causalities in particular those associated with

aviation disasters.

4. Lack of a comprehensive fingerprint database.


Common reasons for identification of

found humans remains • Criminal:

• An investigation to a criminal death cannot begin

until the victim has been positively identified.

• Marriage:

• Individuals from many religious backgrounds cannot

remarry unless their partners are confirmed

deceased.

• Monetary:

• The payment of pensions, life assurance and other

benefits relies upon positive confirmation of death.


• Burial:

• Many religious require that a positive identification

be made prior to burial.

• Social:

• Society’s duty to preserve human rights and dignity

beyond life begins with the basic premise of an

identity.

• Closure:

• The identification of individuals missed for

prolonged periods can bring sorrowful relief to

family members.


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?

Types of identification methods

• Comparative Dental Identification

• Dental Profiling

• Rugoscopy: Study of Palatal Rugae

• Cheiloscopy: analysis of Lip Prints

• Ameloglyphics: Examination of tooth prints/

Bite marks


Techniques

• Radiographs

• Photographs

• Dental Records

• Cryogenic Grinding (to obtain broken cell material)

• DNA Profiling

Double Swab Stain Collection – saliva analysis

• Carbon analysis

• Cone beam CT data

• Photographic comparison: facial or dental

superimposition or approximation

• WinID Computer system


• Dental identification takes two

main forms:

1. Comparative identification

2. Post mortem (PM)dental profiling.


1. Comparative identification

• The postmortem (after-death) dental remains

can be compared with antemortem (before-

death) dental records, including

a. written notes,

b. study casts,

c. radiographs etc.

d. to confirm identity.

• High degree of certainty. D. Caroline Mohamed 18

Be careful when filling dental chart


• The forensic dentist produces the postmortem (PM)

record by careful

charting, written descriptions of the dental

structures and radiographs.

• Then, a methodical, systematic comparison can be

done between the PM and AM records.

• Each tooth and surrounding structures are

examined.

• Individuals with many dental restorations are easier

to identify than those with little or no rest. treatment.


• Similarities and discrepancies should be noted

during the comparison process.

• There are two types of discrepancy, those that can

be explained and those that cannot.




• Explainable discrepancies normally relate to the time

elapsed between the AM and PM records.

• If a discrepancy is unexplainable, for example a

tooth is not present on the AM record but is present

on the PM record then an exclusion must be made.


Explainable discrepancies of AM PM comparison


Comparison of Post-mortem (PM) with Ante-mortem (AM)

Radiographs.


Ante mortem Post mortem


Case



• When reporting dental identification, The American

Board of Forensic Odontology recommends that the

conclusions should be limited to the following four:

1. Positive identification

The AM and PM data match in sufficient detail to

establish that they are from the same person.

2. Possible identification

The AM and PM data has consistent features but,

because of the quality of either the PM or the AM

remains or the AM evidence, it is not possible to

establish identity positively.


• Insufficient evidence

• The available information is insufficient to

form the basis for a conclusion.

• Exclusion

• The AM and PM are clearly inconsistent.


Post morten dental profile

• Antemortem records are not available, and no

clues to the possible identity exist,

• a postmortem (after death) dental profile is

completed suggesting characteristics of the

individual likely to narrow the search for the

antemortem materials..


• Features like:

• age,

• sex,

• SES,

• sometimes habits,

• occupation,

• diet and

• diseases,

• can be acknowledged.


Facial reproduction

• If the P.M profile does not elicit the tentative identity of

the deceased it may be necessary to reconstruct the

individual’s appearance during life.

• This is the responsibility of forensic artists who use the

dental profile to help with the facial reproduction.



Means of Identification

• There are three categories examined when

comparing dental records (ante-mortem with post-

mortem) for identification, which are:

• periodontal tissue,

• anatomical features, and

• the teeth.


Means of Identification • Periodontal tissues:

Trabecular pattern, tori and osseous anomalies.

Gingival morphology and pathology.

Periodontal ligament morphology.

Alveolar process and lamina dura.

Presence of foreign bodies: Implants, unretrieved

amalgam particles, surgical instruments, bullets, …



• Anatomical features:

• Sinus configuration: maxillary and frontal

• Anterior nasal spine

• Mandibular canal

• Condylar and coronoid process

• TMJ

• Skull sutures

• Soft tissues features: rugae (rugoscopy) and lip

(cheiloscospy) prints.

• Other


• Teeth: Natural and synthetic (fixed and

removable) • Present

• Missed

• Type

• Position

• Crown / root morphology - pathology

• Pulp chamber / root canal morphology – pathology

• Periapical pathology

• Dental restorations


Teeth abnormalities

• Developmental, i.e., the tooth in question

developed abnormally.

• Acquired at some time after birth. They can

be the result of :

o trauma

o erosion

o occupational insult

o dental work in a clinical setting.

Teeth developmental abnormalities

• Abnormalities of eruption patterns.

• Abnormalities of shape (morphology).

• Missing features, extra features, or atypical

• features.

• Ex:

Dilacerations of crown

or root

anomalies in the number of

cusps or roots,

abnormal enamel deposition, etc.

Teeth developmental abnormalities

• Abnormalities in the number of teeth.

• Adontia,

• Polydontia / partial adontia

• Supernumerary teeth.

Give clues about genetic syndromes

Ectodermal dysplasia

More developmental abnormalities

• Abnormalities in the

spacing or position of teeth.

a. Crowded,

b. Diastema

c. rotated or

d. misaligned.

• Abnormalities in the

size of teeth.

a. Microdontia

b. macrodontia.

Acquired abnormalities

• Repairs, restorations, prostheses

• Dental staining & enamel variation

o Coffee, colas, nicotine

o Erosion

o Occupational

o Health-related issues

o Diet composition

• Occlusal attrition

• Missing teeth

o Premortem vs.

peri/postmortem

Age estimation


Age Estimation

• You can tell age solely by teeth analysis:

• Methods:

1. Require the extraction of teeth and

histopathological examination, and

2. Require radiographs.


Age Estimation

1. The Universal System ( > reliable for children and

adolescents) analysis of dental development & X-ray.

2. Gustafson

Looking for six signs of wear

3. Lamendin / Johansen methods

Transparency of radicular dentin (older the person >

translucent the root dentine) and secondary dentin

deposition.


The Universal System Analyzing Teeth

1. Teeth are given a

specific number.

(Primary teeth are

given specific capital

letter)

2. Any dental work done

on surface is noted

3. Sheets kept on dental

file forever. When

person is missing,

files are transferred to

the missing person’s

office


FDI Dental Federation notation system





Teeth identification and chronology


Teeth through the years Childhood Adulthood


• Primary teeth sprout from milk buds

and are temporary. Once they fall

out, permanent teeth as seen on the

other side appear.

Permanent adult teeth come in when primary teeth fall out; they are permanent because they establish roots inside the gums. Third molar come in around the mid teenage years.


Eruption sequence and timing

Primary teeth

Permanent teeth




May you help me to solve those cases?

What ´s the patient’s age?

Stan

dard

Teeth

D

evelo

pm

ent fo

r A

ge D

etermin

ation


Around 3 to 4 years



11-13 YEARS

6 TO 9 YEARS



17- 30 YEARS Aprox.

Estimating age

• Third molar in age estimation: • A valuable indicator in the age 16-23 years but

questionable now a days due

to great variation in genesis, position,

morphology and time of formation


Estimating age

• The third molar may provide reasonable accuracy for

the likelihood that a person is

at least 18 years of age,

rather than giving the exact chronological age,

due to the absence of any other marker

in the late adolescence.

• Regression formulas can be calculated and

statistical analyses gives the correlation between the

findings and possible age for a specific population.





• UT-AGE, freeware automates calculation of

mean age, and the empirical probability of

attainment of the 18th year of age.

• This calculation is based on third molar

development population group studies.

• spacer

Estimating age

• The presence of erosion can suggest:

alcohol or substance abuse,

an eating disorder or

even hiatus hernia

• while stains can indicate smoking,

tetracycline use or betel nut chewing.

• Unusual wear patterns

pipe stems, cigarette holders, hairpins,

carpet tacks or previous orthodontic

treatment.


Age estimation more acuity analysis

3. Cone beam CT data renders volumetric information

on tooth/pulp ratios leading to dental age

estimations in living and dead individuals.

4. Radiocarbon analysis of tooth enamel

gives an precise year of birth, and obtain clues to the

victim’s geographic origin.

5. Aspartic acid Racemization analysis of dentin

gives the chronological age of the individual at the

time of death.


Effects of aging on human skull





Osteoporosis and the impact of

tooth loss. D. Caroline Mohamed 78

Socio Economic Status

• The quality, quantity and presence or absence of

dental treatment may give an indication of socio-

economic status or likely country of residence.


Sex and ancestry • Ancestry can be assessed by studying the facial

skeleton and comparing the features with the main

characteristics of the three racial groups:

Mongoloid

Negroid

Caucasoid

Additional characteristics, such as cusps of Carabelli,

shovel-shaped incisors and multi-cusped premolars,

can also assist in determination of ancestry.




Sex estimation



Male and Female Cranium Differences:

A)The men cranial mass is more blocky

and massive / females is rounder and

tapers at the top.

B) Temporal Ridge . More prominent in

men than women.

C) A woman’s supraorbital margin is

sharper, while the males is rather round

and dull.

D) The Zygomatic bone is more

pronounced on the male skull.

E) The Mandible (lower jaw) bone of a

woman is rounded, while the male’s is

squared.


Male and Female Cranium

Differences:

F) Frontal bone – woman forehead

structure terminates at the brow. The

male forehead is lower and more

slopping.

G) Men have a deeper cranial mass.

H) The supercilary arch is large and

rounded in the man.

I) A males gonion is more flared out

and sharply angled.

J) The teeth of men tend to be larger.

• Sex determination is usually based on cranial

appearance.

• Microscopic examination of teeth can confirm sex by

the presence or absence of Y-cromatin from the

teeth pulp ( Bar bodies)

• and DNA analysis from saliva and pulp can also

reveal sex.


• Cold case • Investigators were unable to establish a tentative

identification and requested a postmortem dental

profile.


Analyzing the skull and

teeth can you tell me the

sex, age, some habits and

maybe where did he live?


Skeletal pattern and dental characteristics

suggested the following profile:

Caucasian,

male,

aged 25–35 years at death,

moderate adult periodontitis,

nicotine stains,

lack of recent dental treatment and

previous treatment to Canadian standards.


• Using this information, a forensic artist produced a

facial reproduction.

• Subsequently, the body was identified as that of a

28-year-old missing white male smoker.



1.Activity • Look at a printed OPG and mark major

features on the dental chart provided as you

doing a comparative AM profile.

• Look for :

• Cavities

• Fillings

• Bridegework

• Missing teeth

• Malocclusion



2.Activity • Have an alginate impression of your upper and low

dentition and make a case study model.

• Take a picture of the model ( 90 degree) and bring

with you the model and picture for next lecture.


33.forensic

Health & Medicine

caroline mohamed

forensic odontologists

forensicodontology bafo

branch of forensic medicine

identification of individuals

positive identification

use of identification

o vienna opera house