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.

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

• 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
officeD. Caroline Mohamed 49

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?

StandardTeeth
Developmentfor
AgeDeterminationD. Caroline Mohamed 61

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.

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

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33.forensic