Here's an introduction to the field of Forensic Odontology; role and scope. A summary of the type of cases where the expertise of an odontologist is required. Special emphasis is given on the dental profiling.
• Forensic Odontology is the application of dental science to the administration of the law
and the furtherance of justice.
• The application of principles & expertise of dentistry for the purpose of law & criminal
• Branch of dentistry which deals with the proper handling, examination & evaluation of
dental evidences and with the proper presentation of dental findings in the interest of
• Forensic dentistry is a specialty that relates dental evidence to investigation.
It provides an important community service in both the civil and criminal jurisdictions.
Forensic dental services are of value both in death investigations and in clinical forensic
medicine for evaluation of living victims of sexual assault, child abuse & other domestic
10/6/2016 1saurabh bhargava
Dentistry Vs Forensic Odontology
• Dentistry is the "evaluation, diagnosis, prevention and/or
treatment (nonsurgical, surgical or related procedures) of
diseases, disorders and/or conditions of the oral cavity,
maxillofacial area and/or the adjacent and associated
structures and their impact on the human body". Dentistry is
necessary for complete oral health.
• Forensic odontology is the proper handling, examination
and evaluation of dental evidence, which will be then
presented in the interest of justice. The evidence that may
be derived from teeth, is the age (in children) and
identification of the person to whom the teeth belong. This
is done using dental records or ante-mortem (prior to death)
10/6/2016 2saurabh bhargava
•The THEORY behind forensic dentistry is that no two mouths are alike
(even identical twins are different), and that teeth, like tools, leave
•Most people have dental records, or these can be created through
making a dental impression from a suspect. These can then be
compared to either teeth found on a corpse or bite marks found at the
scene of a crime.
•It relies on sound knowledge of teeth and jaws, possessed by dentist
and incorporates dental anatomy, histology radiography, dental
materials and developmental anomalies of dentition.
•The interpretation of dental evidence is a specialist task, undertaken by
a forensic odontologist who may be called as an expert witness in a
10/6/2016 3saurabh bhargava
• 1st dental identification was made between 49-66 AD ( Agrippina ,Emperor
Claudius , Lollia Paulina).
• King William ; 1066 AD is supposed to be the 1st to use bite marks for
• The earliest known identification from teeth is in 1775 by Paul Revere.
– Paul Revere made a silver bridge for one man. The man was killed in the
– Body was in mass grave and identified by his silver dental work.
• 1837- Dr Edwin Saunders established the eruption sequence.
• 1897- Dr Oscar Amoedo ( father of forensic odontology ) wrote the first book of
forensic dentistry→ L’Art Dentaire en Medicine Legale.
10/6/2016 4saurabh bhargava
High profile cases
• Ted Bundy was identified from a
• John Wilkes Booth was
identified by a “gold plug” on
the right side of his jaw.
• Elaborate dental records
including radiographs and spare
crowns identified the body of
• Another famous case involving
the use of forensic dentistry for
identification was that of Czar
10/6/2016 5saurabh bhargava
• American Society of Forensic Dentistry (1970).
• International Society for Forensic Odonto-
• Similar organizations exist in various countries.
10/6/2016 8saurabh bhargava
• Forensic dentistry plays a major role in identification in man made
or natural disaster –events that result in multiple fatalities that may
not be identifiable through conventional methods such as finger
• This field is very important in identifying human remains that are
decomposed, mutilated, or visually unrecognizable.
• The scope of forensic odontology is wide and includes the
identification of victims of transport accidents, gunshot/heavy
artillery, and incineration in vehicles and house fires.
• It also includes the examination of bite marks inflicted by humans
(commonly found in violent crimes & child abuse cases) and
animals in a variety of circumstances.
• Teeth marks may be left in food, pencils or other items left at crime
10/6/2016 9saurabh bhargava
Scope of Forensic Odontology
1. Identifying unknown human remains through dental records & cranio-
2. Age estimation of both the living and deceased.
3. Recognition and analysis of bite marks found on victims.
4. Analysis of oro-facial trauma associated with person abuse.
5. Determining the gender of an unidentified individual.
6. Eliciting the ethnicity.
7. Assisting in building up a picture of lifestyle and diet of skeletal remains.
8. Analysis of dental malpractice claims.
9. Presenting evidence in court as an expert witness.
10/6/2016 10saurabh bhargava
Parameters to be compared..
2. Prosthetic appliance– bridges, partials,
crown, false teeth.
3. Shape, form (morphological) peculiarities.
4. Genetic anomalies.
10/6/2016 11saurabh bhargava
• Each tooth has a crown (visible
portion that protrudes above
gum) and a root (embedded into
the socket in the jaw bone).
• Crown is capped by enamel ,
under the enamel is a layer of
dentin which surrounds the pulp
• The root is surrounded by
• Periodontal ligament present
between cementum and bone of
the jaw holds the tooth in jaw.
10/6/2016 13saurabh bhargava
Two arches present in the oral
Since both arches are
symmetrical ; the whole dentition
is divided into 4 quadrant ; each
containing the same number &
same types of teeth , as-
•2 Pre molars
MANDIBLE AND MAXILLA
10/6/2016 14saurabh bhargava
10/6/2016 15saurabh bhargava
• Eight in number (four in
• Anterior teeth with
wide crown and thin,
sharp, chisel like
incisal/ cutting edge
• Has a single root
• Used for cutting
10/6/2016 18saurabh bhargava
• Four in number ( two in each arch )
• Also called cuspid, as they have a
• Present at the corner of the arch
• Has a single root
• Used for tearing of the eatables;
that’s why more prominent in
10/6/2016 19saurabh bhargava
• Eight in number ( four in each arch )
• Present only in permanent dentition
• Each premolar typically has two cusps
• Premolars (other than 1st maxillary premolars
which has two roots) possess a single root
10/6/2016 20saurabh bhargava
• Twelve in number (six in each
• Posterior most teeth in
• Usually have 3-5 cusps
• Multi-rooted teeth.
• Wide occlusal surface adapted
for chewing & crushing of food.
• 3rd molar is the last tooth to
10/6/2016 21saurabh bhargava
Incisors (I) Adapted for biting, cutting and stripping
Canines (C) Adapted for seizing, piercing and tearing
Adapted for grinding, crushing, shearing and
Molars (M) Adapted for grinding and crushing
Each type of tooth is adapted to perform the
specific functions listed below.
10/6/2016 22saurabh bhargava
• A mammal's dental formula designates the number of each
type of tooth found in its dentition
• It provides one kind of quantitative measure of the
– different sexes and ages of the same species,
– different species, and
– animal groups having different feeding strategies or diets
• Dental formulas are used to quantify difference between
• Our specific goal in this studying the dental formulae is to be
able to quantitatively compare and identification of
carnivores, herbivores, omnivores, and an insectivore.
10/6/2016 23saurabh bhargava
Can you tell the differences of these
10/6/2016 24saurabh bhargava
What to look for..?
• The shape or curvature
• No. of tooth marks
• Horizontal diameter
• Vertical diameter
• Depth of depression
• Distances between two teeth
• Orientation of each tooth
• Other reasonable answers
10/6/2016 25saurabh bhargava
Dental formula of a human adult is:
i 2/2, c 1/1, pm 2/2, m 3/3
10/6/2016 26saurabh bhargava
Identify the most probable animal just
by looking at the dentition
10/6/2016 27saurabh bhargava
Identify the most probable animal just
by looking at the dentition
10/6/2016 28saurabh bhargava
Identify the most probable animal just
by looking at the dentition
10/6/2016 29saurabh bhargava
Identify the most probable animal just
by looking at the dentition
10/6/2016 30saurabh bhargava
Tooth type & Diet type
• Tooth size, shape, and arrangement in the mouth are
important determinants of the type of food an animal can
obtain and consume.
• Teeth can be used to tell what type of diet an animal has.
• Four major groups of animals with respect to diet
– Carnivore (meat eater)
– Herbivore (plant eater)
– Insectivore (insect & worm eater)
– Omnivore (an animal that eats a variety of foods including meat
10/6/2016 31saurabh bhargava
Carnivores share special adaptations
for life as predators.
10/6/2016 saurabh bhargava
• Large slicing canines for piercing the skin
of prey, and for cutting and chewing
• Pointed incisors for tearing flesh
• Even the cusps on a carnivore’s molars
are high and pointed, because these
teeth too are used in tearing and
• Long roots on all teeth so that they are
well anchored for working on the tough
• Carnivores also have front facing eyes,
heavy skulls that support the large
muscles needed to work the jaws, and
jaws that are very strong but that move
only up and down, not from side to side.
• Feed on plant material. They need to clip
green leafy material off from grass roots
(grazers) and tree branches (browsers). The
cellulose in leaves is ground down into a
mash that can be more easily digested.
• Incisors have a flat cutting edge, for use in
clipping off plant stems. Since these teeth
wear down from this work, there is
continuous tooth growth in many species.
• Canines are often lacking entirely, as the
food does not need to be captured, though
squirrels may have pointed incisors that look
like canines, which they use to break nuts
• Molar teeth are tall and very broad. They
have flat upper jaw surfaces sometimes with
ridges on them to help grind plant material.
10/6/2016 33saurabh bhargava
• They have a mouthful of sharp
little peg-like teeth that are
similar in size and shape.
• These are used in seizing and
crushing hard-shelled insects,
and for gripping on to worms
as they are pulled from their
10/6/2016 34saurabh bhargava
• Omnivores have the most variable
teeth, used for eating both plant
and animal material that make up
their broad diet.
• Incisors are more shovel-shaped
• Long, sharp canines are used for
puncturing and grabbing onto
• Wide molar and premolar teeth
handle both the chewing of meat
and the grinding of plant material.
They have low bumpy crowns.
10/6/2016 35saurabh bhargava
Dental Identification is Required
– Decomposing remains
– Skeletonized remains
– Charred remains
– Doe Identification; Intact remains without any
– Scientific verification of identity is anticipated
– Multiple bodies recovered from a common
– Mass disaster
10/6/2016 36saurabh bhargava
ESTABLISHMENT OF A PERSONAL IDENTIFICATION
IS REQUIRED FOR LEGAL AND HUMANITARIAN
• Legal aspects-
- Charging the suspect with a crime
- Will probation
- Insurance benefits
- Bussiness matters
- Lawsuits settlement
- Remarriage sanction
- Settlement of property related issues
• Humanitarian aspects-
- Proper interment/cremation according to
religion & family wishes.
10/6/2016 37saurabh bhargava
Methods of Identification
• Visual recognition by acquaintances
• Personal effects/belongings
(Rigor mortis, decomposition, animal predation,
deliberate misidentification, borrowed & stolen objects
etc can obscure the visual identification).
• Fingerprinting technique
• Dental identification
• DNA techniques
(Scientific, reliable, valid and objective techniques)
10/6/2016 38saurabh bhargava
Dentition; a perfect identifier..?
• Written below are the qualities that are present in dentition and associated
structures ; making them the perfect scientific identifier –
1. Stable & durable (tooth material & restorative materials)
– Teeth are the most durable organs in the body and can be heated to temperature
of 1600°C without appreciable loss of micro structure.
2. Uniqueness (size/shape/pattern/wear/repair)
– The 16 missing teeth can produce is approximately 600 million different number
of combinations .
– Four missing and four filled teeth in a mouth combined can produce more than
700 millions combinations.
– Although teeth are relatively resistant to environmental insults after death,
during life they are susceptible to physiological and pathological changes.
3. Previous records
10/6/2016 39saurabh bhargava
A perfect identifier..??
• Since teeth can resist extreme conditions, they are
the excellent source of DNA.
• This facilitates comparison with the known
biological ante-mortem sample of the person such
as hair, epithelial cells from a tooth brush or a
• If the persons ante-mortem sample is unavailable,
the DNA pattern may be compared to a parent or a
sibling, thus allowing identification.
10/6/2016 40saurabh bhargava
1. Oral autopsy
2. Securing ante-mortem
5. Writing the final report
•WHEN ANTE-MORTEM RECORDS ARE
•INCLUDES A TRIAD OF
INFORMATIONETHNIC ORIGIN ,
GENDER , AGE etc
•INFORMATION FROM THIS PROCESS WILL
ENABLE A MORE FOCUSSED SEARCH FOR
ANTE-MORTEM RECORDS10/6/2016 41saurabh bhargava
• It involves examination of deceased, usually with dissection to expose the
organs, to determine the cause of death.
• It has a systemic protocol starting with critical examination of external
features of the body such as gender, ethnicity, build, wounds, scars,
• Oral examination is an essential part of post-mortem procedure.
• A thorough examination of soft tissue injuries, fractures and presence of
foreign bodies is undertaken and samples of hard and soft tissues may be
obtained for further investigations.
• All this information is entered on to the standard “Interpol postmortem
form” which is color coded in pink.
10/6/2016 42saurabh bhargava
Obtaining Dental Records
• Dental records contain information of treatment and
dental status of a person during his/her lifetime.
• Such records may be in the form of dental charts, radio
graphs, casts and/or photographs.
• The contents of all available dental records should be
transcribed onto the standard “Interpol ante-mortem
form” which is color coded in yellow.
10/6/2016 43saurabh bhargava
Comparing Post- and Ante-Mortem
• Once the post-mortem evidence and dental records
are available, the data can be compared.
• Features compared include tooth morphology and
associated bony structures, pathology and dental
10/6/2016 44saurabh bhargava
Writing A Report and Drawing
• One needs to remember that any attempt at establishing identity is
addressed to the legal authorities.
• Therefore, a detailed report and factual conclusion, based on
comparison, must be clearly stated.
• Acharya and Taylor have suggested a range of conclusions, which
1. Confirms Identification
2. Probable Identification
3. Possible Identification
4. Insufficient Information
5. Excludes Identification
10/6/2016 45saurabh bhargava
Division of work among different dental teams in mass
disaster identification programme
Post-mortem unit Ante-mortem unit Comparison unit
• Photography, collection of
personal belongings, finger
printing, full body
precede the dental
•Charts, x-rays, specimens
are labelled, initialled and
delivered to comparison unit
•Most difficult part
•Gathers as much
information as possible
•Tries to collect the ante-
mortem dental records in
the form of X-rays, dental
charts, dental photographs,
plaster modals etc
dental office etc
•Constitutes the ante-
mortem charts and deliver
them to comparison unit
•Comparison & confirmation
•Ante-mortem and post-
mortem dental records are
analyzed & compared either
manually or with the help of
•Final decision on
identification/ verification is
done by the chief
10/6/2016 46saurabh bhargava
Identification From Dental DNA
• The conventional method of dental identification described thus far requires one
basic element that may not always be readily available- adequate or complete
• Since teeth can resist extreme conditions, they are the excellent source of DNA.
• Routinely applied technique in forensic investigations, known as polymerized
chain reactions allows amplification of even highly degraded DNA.
• This facilitates comparison with the known biological ante-mortem sample of the
person such as hair, epithelial cells from a tooth brush or a biopsy specimen.
• If the person’s ante-mortem sample is unavailable, the DNA pattern may be
compared to a parent or a sibling, thus allowing identification
10/6/2016 47saurabh bhargava
The Role of Palatal Rugae in
• Useful in edentulous persons
• Rugae patterns like teeth are
considered unique to an individual
• Rugae patterns on the decedent’s
maxilla or maxillary dentures may be
compared to old dentures that may
be recovered from the decedent’s
residence or plaster model from
10/6/2016 48saurabh bhargava
• Dental profiling includes extracting a triad of
information-the decedent’s ethnic origin, gender
• The information from this process will enable a
more focused search for ante-mortem records .
• There are a total of three steps in a dental
10/6/2016 50saurabh bhargava
Identifying Ethnic Origin From Teeth
• Anthropologists have divided race into following broad groups-
(v) American Indians
• Dental features used to describe population differences are broadly
categorized as metric (tooth size) and non metric (tooth shape).
• Metric features are based on measurements and non metric in
terms of presence or absence of a particular feature , e.g: whether
carabelli’s cusp is present or absent.
10/6/2016 51saurabh bhargava
• Size of teeth: Both deciduous and permanent dentitions are
considered. The size of the teeth varies in different races
• Larger teeth are seen in Australian, South American Indian
• Lateral incisor is relatively large compared to central incisor
• Intermediate sized teeth are seen in Taiwanese Aborigines
and Australian whites respectively.
10/6/2016 52saurabh bhargava
Scott and Turner suggested that characteristic dental features have evolved over
time as a result of genetic and environmental factors that have influenced different
population groups. More than 30 non-metric features of the tooth crown and root
have been describe and analyzed by Scott and Turner.
• NON METRIC FEATURES OF CROWN
2. Double shoveling
3. Carabelli’s feature
4. Three cusped upper 2nd molar
5. Cusp 5
6. Cusp 6
8. Five cusped lower second molar
9. Lower molar groove pattern
10. Interruption groove
11. Enamel extension
13. Lateral incisor variants
14. Distal accessory ridge
15. Premolar accessory ridge
16. Premolar lingual cusp
17. Mesial marginal complex of upper
• NON METRIC FEATURES OF ROOT
1. Two-rooted upper premolar
2. Two rooted upper molar
3. Two rooted lower canine
4. Three rooted lower molar & Single
rooted lower molar etc.
10/6/2016 53saurabh bhargava
Sex Determination From Teeth
• Determining the sex of unknown human remains is the second step in building a
• Gender can be determined based on data from---
– Cranio-facial morphology and dimensions
– Sex differences in tooth dimensions
– Tooth morphology
– Sex determination by DNA analysis
• Amelogenin (AMEL) is one of the major matrix proteins secreted by the
ameloblasts of the enamel.
• The AMEL gene, coding for a highly conserved protein, is located on X- and Y
chromosomes in humans.
• Thus the females (XX) have two identical AMEL genes but the males (XY) have two
non identical genes.
• Preparing DNA from teeth by ultra sonification, and subsequent PCR amplification,
100% success in determining the sex of the individual has been obtained by some
10/6/2016 54saurabh bhargava
10/6/2016 saurabh bhargava 55
• Mandibular cuspid shows the maximum sexual
– Mesio-distal diameter < 6.7 mm (in females)
– Mesio-distal diameter > 7 mm (in male)
– Root length of maxillary cuspid is >3 mm more in males than
– Distance b/w tips of coronoid processes(cm) x distance b/w
angles of jaw…
if > 90 ; then male
if < 78 ; then female
Age estimation from dentition
• The final step in triad of dental profiling, age estimation is an
important subspecialty of forensic sciences.
• Dental age estimation makes use of morphologic, radiographic,
histologic, and biochemical methods to examine the age dependent
changes in teeth.
• It is grouped into three phases:
1. Ageing in prenatal, neonatal and early postnatal.
2. Age estimation in children and adolescents.
3. Age estimation in adults.
10/6/2016 saurabh bhargava 56
10/6/2016 saurabh bhargava 57
Phases in tooth development and
1. Utero ( from 16 weeks) to eruption of 1st tooth
at 6 months.
2. Primary dentition (milk teeth): from 6 months to
3. Mixed dentition: 6 to 12 years.
4. Permanent dentition: From 12 years on
10/6/2016 saurabh bhargava 59
• Presence of neonatal line indicates a live births
• By dry weight of mineralized tooth (at six month IU- 60mg, newborn-0.5g, six
month post natal-1.8g)
• Histological examination is more precise in neonatal age estimation than
• Examining teeth eruption patterns
• Gustafson method (looking for six signs of wear)
• Lamendin method (looking at transparency of roots/dentin translucency)
• Age estimation based on ratio of D-Aspartic acid to L-Aspartic acid
10/6/2016 saurabh bhargava 65
• This method is based on morphological and histological changes of the teeth.
• This assessed regressive changes such as:
a) Amount of occlusal attrition(A)
b) Coronal secondary dentine deposition(S)
c) Loss of periodontal attachment(P)
d) Cementum apposition at the root apex(C)
e) Root resorption at the apex(R)
f) Dentine translucency(T)
An+ Sn+ Pn+ Cn+ Rn+ Tn = X; a total score
•Age was estimated using the formula
Age = ( 11.43 + 3.63X ) years
•It was found that an increase in the total score corresponds to an increase in age
• For each of these regressive changes or variables, different scores ranging from 0-3 were assigned.
STAGE 0 – indicates no change
STAGE 1 – beginning of change
STAGE 2 – obvious change
STAGE 3 – maximum change
A1—attrition limited to enamel level
A2—attrition limited to dentine level
A3—attrition up to pulp cavity
Secondary Dentin (S)
S0—no secondary dentin formation
S1—secondary dentin up to upper part of pulp cavity
S2—secondary dentin up to 2/3rd of the pulp cavity
S3—diffuse calcification of entire pulp cavity
Periodontal Disease (P)
P0—no obvious periodontal disease
P1—beginning of periodontal disease but no bone loss
P2—periodontal disease more than 1/3rd of the root
P3—periodontal disease more than 2/3rd of the root
10/6/2016 saurabh bhargava 66
Root Translucency (T)
T1—beginning of translucency
T2—translucency more than 1/3rd of the apical root
T3—translucency more than 2/3rd of the apical root
Cementum Apposition (C)
C1—thickness of cementum more normal
C2—abnormal thickness of cementum near the apex of the root
C3—generalized abnormal thickness of cementum throughout the apex of the root
Root Resorption (R)
R0- no resorption
R1- apical 1/3rd root resoption
R2- apical 2/3rd root resorption
R3- comlete root resorption
• Kashyap and Koteswara Rao omitted periodontosis and root resorption from Gustafson’s method and
calculated the index values of various parameters undergoing regressive changes.
• Their modified method gave an error of + 1.59 years
10/6/2016 saurabh bhargava 67
• Bang and Ramm were the first to use dentine translucency alone
for estimating age.
• Root dentine starts to become translucent during the third decade
(30s) of life beginning at the apex and advancing coronally.
• Root dentin starts to become translucent due to the increased
• Therefore dental root translucency increases with advancing age.
• AGE = B0+B1X where B0 –regression constant
X-length of translucency
10/6/2016 saurabh bhargava 68
Amino acid racemization
• All amino acids (except glycine) are optically active, having a stereocenter at their α-C atom.
• This means that the amino acid can have two different configurations, "D" or "L" which are mirror images
of each other.
• Living organisms keep all their amino acids in the "L" configuration.
• When an organism dies, control over the configuration of the amino acids ceases, and the ratio of D to L
moves from a value near 0 towards an equilibrium value near 1, a process called racemization.
• Thus, measuring the ratio of D to L in a sample enables one to estimate how long ago the specimen died.
• Helfman and Bada first suggested a relationship between dentinal age and the extent of aspartic acid
racemisation in dentine.
• The extent of racemization of aspartic acid in coronal dentin of normal permanent teeth can be used to
estimate the age of an individual at the time of death.
• This method is accurate with age estimates within plus/minus three years of actual age.
10/6/2016 saurabh bhargava 69
Some other techniques of age
1. Pulp diameter to crown diameter ratio and pulp / root length,
pulp /root width was measured.
2. An interesting method using intensity of fluorescence in dentin
and cementum, which shows strong correlation between age,
deepening of colour of the tooth and increase in intensity of
fluorescence. The colour changes in the cementum and dentin are
caused by infusion of decomposition products from erythrocytes.
3. The incremental lines of cementum will help to determine the age
of adults. A major disadvantage of this method is the necessity to
extract or section the tooth. It is not practical among living
10/6/2016 saurabh bhargava 70
• Cutaneous bitemarks represent patterned injuries in skin produced
• A mark caused by teeth either alone or in combination with other
mouth parts (Mac Donald).
• May be inflicted by humans or animals (most commonly by dogs
and cats); may be on tissue, food items or other objects.
• Those of forensic signiﬁcance most often accompany violent crimes
such as homicide, sexual assault, child abuse, domestic violence,
10/6/2016 saurabh bhargava 71
10/6/2016 saurabh bhargava 72
• Human bite broad, U-shaped somewhat circular or
• Animal bite narrow in the anterior aspect , V shaped
and elongated also morphology of the teeth is
Usual Sites of Bite Marks
• Females on breast, legs( inner part of thigh)-sexual assault
• Children genitals, oral & paraoral regions-child abuse
• Adult Males finger, arms and shoulders-fight
10/6/2016 saurabh bhargava 73
• Each human dentition is unique, differing even in
• Its imprint in skin can show this individualization,
making the identification of perpetrator possible
• For this reason, bite marks have been referred to
as “dental fingerprints”.
10/6/2016 saurabh bhargava 74
Objectives of bite mark investigation
• To recognize the bite mark
if a patterned injury is not detected or recognized as a bite
mark, the entire investigation is pre-empted because the
forensic dentist will not be notified.
• To ensure that they are accurately documented
proper photography, collection etc is must to make the further
comparisons with ante-mortal records
• To compare them to the teeth of alleged perpetrator
comparison of impression, photographs with gypsum replicas of
10/6/2016 saurabh bhargava 76
Diagrammatic depiction of human bite mark showing typical
pattern of contacting surfaces of teeth
• Is composed of two separate, curved arches facing one another.
• Each arch is composed of a row of contusions, abrasions, lacerations or depressions
approximating the size & shape of biting surfaces of human front teeth.
10/6/2016 saurabh bhargava 77
Typical presentation of bite mark
• A representative human bite is described as an elliptical or circular injury
that records the specific characteristics of the teeth
• Alternatively, it may be composed of two U-shaped arches that are
separated at their bases by an open space.
• The diameter of the injury typically ranges from 25-40 mm.
• This extra-vascular bleeding is caused by pressure from the teeth as they
compress the tissue inward from the perimeter of the mark.
Caninestriangular or rectangular
Premolars and molars spherical or point shaped
Rotation, Dental work, diastema, fracture etc.
CLASSIFICATION OF BITE MARKS
A. Cameron and Sims Classification
1. Causing Agents
2. Substrate Materials
-Skin , body tissue
B. Mac Donald’s classifications
-Tooth pressure mark
-Tongue pressure mark
-Tooth scrape mark
10/6/2016 saurabh bhargava 78
10/6/2016 saurabh bhargava 79
C. Based on severity of injury
a. hemorrhage -- small bleeding spot
b. abrasion -- undamaging mark on skin
c. contusion -- ruptured blood vessel, bruise
d. laceration -- punctured or torn skin
e. incision -- neat puncture of skin
f. avulsion -- removal of skin
10/6/2016 saurabh bhargava 80
Bite marks analysis
1. Recognition (human or animal bite mark)
2. Documentation (Photography/sketching)
3. Evidence collection and preservation
(DNA and physical evidence).
4. Physical dental proﬁling of the
questioned evidence (bite mark).
5. Physical dental proﬁling of the known
6. Physical comparison of (4) and (5)
7. Communication of results to authorities
and legal counsel.
10/6/2016 saurabh bhargava 81
Bite Mark Investigation
• Preliminary questions
• Bite mark evidence collection from the victims
-WBC and sloughed epithelial cells, potential source of DNA
4.Impression: Vinyl polysiloxane, dental acrylic & plaster
• Evidence collection from suspect:
using a signed and informed consents or a court order (warrant)
also include photograph, two casts, bite registration in centric
occlusion and saliva swab from buccal vestibule
Bite marks investigation
• Physical characteristics to be studied are-
– Distance from cuspid to cuspid
– Tooth alignment
– Teeth width, thickness, spacing
– Missing teeth
– Wear patterns including chips and grinding
– Dental history including fillings, crowns, etc.
10/6/2016 saurabh bhargava 82
10/6/2016 saurabh bhargava 83
Structural variations in teeth
(human vs non-human)
• Dentition differs greatly among various organisms
• Most animal teeth reflect specialized dietary
adaptations eg.- grazing animals have more
grinding teeth unlike carnivores which have more
• Each animal has a different dental formula (no. of
each tooth type in a quadrant of mouth)
10/6/2016 saurabh bhargava 84
Animal Features of dentition
Fish conical, homodont, heterodont or polyphydont
Reptiles homodont conical or only tricuspid teeth
Venomous snake single row, palatal to this are two poison fangs
containing canal or groove for venom release
Non- venomous snake two rows of maxillary teeth
Carnivorous Larger, sharper, conical canines
Other mammals heterodont dentition, diphyodont also have
accesssional teeth( permanent molar emerge
posterior to deciduous teeth)
10/6/2016 saurabh bhargava 85
Positive bite-mark Possible bite-mark Definite bite-mark
•An injury showing a pattern
that may or may not be
caused by teeth; could be
caused by other factors but
biting cannot be ruled out.
•• criteria: general shape and
size are present but
distinctive features such as
tooth marks are missing,
incomplete or distorted or a
few marks resembling tooth
marks are present but the
arch configuration is missing.
•The pattern strongly
suggests or supports origin
from teeth but could
conceivably be caused by
•• criteria: pattern shows
some basic general
characteristics of teeth
arranged around arches.
•There is no reasonable
doubt that teeth created the
pattern; other possibilities
were considered and
•• criteria: pattern
(classic features) (all the
characteristics) (typical class
characteristics) of dental
arches and human teeth in
proper arrangement so that it
is recognizable as an
impression of the human
10/6/2016 saurabh bhargava 86
Human or Animal bite
10/6/2016 saurabh bhargava 87
Dental Malpractice Claims
Malpractice suit claims
-Alterations of face , jaw ,
-Unnecessary dental work
Role of Forensic
• Examines dentition &
oral tissues to establish
degree of trauma , its
possible cause and its
potential impact on
ability to chew food
regarding their findings
10/6/2016 saurabh bhargava 88
Oral findings of child
Multiple broken, discolored, missing or
Repeated episodes of mouth trauma
Peculiar malocclusions & non occluding
Healed jaw fractures which were
Laceration of labial or lingual frena Forceful lip pulling or slapping
Isolated laceration of soft palate Insertion of utensils during forced feeding
Horizontal abrasions or contusions
extending from lip commissures
Application of gag
Bite marks on skin Child bite (unsupervised children), adult
bite (anger biting)
Rampant caries/Nursing Bottle Syndrome Possible child neglect
Venereal disease Gonococcal stomatitis, syphlitic lesions
indicates sexual abuse
10/6/2016 saurabh bhargava 89
FORENSIC ODONTOLOGIST AS AN
• FREQUENTLY CALLED IN TO GIVE SWORN TESTIMONY
IN COURTROOMS IN VARIOUS CASES SUCH AS-
BITE MARK ANALYSIS
CHILD ABUSE CASES
DENTAL FRAUD etc.
10/6/2016 saurabh bhargava 90
Shortcomings of dental
• Difficult to locate than fingerprints
• Records may be inadequate
• No standardization of dental records (no recognized minimum no. of concordant
features required for positive identification)
• Written entries are subject to error
• Alterations (decayed , filled or extracted) after the last ante-mortem entry