Forensic Odontology overview

2. Group 1
• Adeen Farooq
• Beenish Sarfraz
• Hina qaiser
• Medhat sabir
• Rabia aslam

3. Why Teeth
 Each human has an individual set of teeth which can be traced back to
establish dental records to find missing individuals.
 Teeth is made of enamel (hardest tissue of the body) so it can withstand trauma
(decomposition, heat degradation, water immersion, and desiccation) better than
other tissues in body.
 Teeth are a source of DNA: dental pulp or a crushed tooth can provide nuclear or
mitochondrial DNA that to help identify a person.

4. Forensic Dentistry
or
Forensic Odontology
Definition:
Forensic – Forum means ‘Court of Law’
Odontology – Study of teeth
• Branch of forensic sciences which deals with
collecting, preserving, recording and
interpretation of dental evidence at the interest
of court of law to offer law enforcement.

5. • History of forensic dentistry dates back 4500 years
• One of the first dental identification was recorded in 2500
BC, when 2 molars linked together by gold wire were found
by Junker in a tomb located at Giza
• 17th century : identification of bodies using dental details
known to dentist
• German dictator ADOLF HITLER and Pakistani President
General ZIA-UL-HAQ were identified on the basis of dental
evidences
• 19th century: criminal convicted on dental evidence
• In 1897, first paper on forensic odontology published
• In 1906, first time in history bite marks accepted as an
evidence, person was convicted for murder on this basis.
History of Forensic Dentistry
Father of Forensic Odontology
Dr. OSCAR AMOEDA

6. Subject Division
Forensic odontology
Civil
1. mal practice
2. Identification of bodies
3. Natural disasters
Identification of a
living person- loss of
memory.
Criminal
The identification of persons
from their teeth - living/dead
person.
Bite marks - food stuff, on
the assailant, on the
victim- self
inflicted/inflicted by
another
Research
Academic training

7. Organizations of Forensic Odontology
Bureau of Legal Dentistry (BOLD)
American Board of Forensic
Odontology (ABFO)
International Organization for Forensic Odonto-
Stomatology (IOFOS)

8. Teeth Basics
• Approximately 32 teeth in adult mouth
• Four types of teeth:
• Molars
• Premolars
• Canine
• Incisors
• Teeth differ in:
• Size
• Shape
• Root type
Types of teeth
Left to right: Incisor, Canine, Premolar,
molar.

9. Individual Characteristics
 Size of tooth
 Shape of tooth
 Shape of root
 Placement of tooth
 Quantity of teeth
 Combinations of dental work done:
Crowns
Extractions
Bridge
Fillings
Root canals
Variousdentalwork

10. Childhood Adulthood
Teeth Through the Years
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.

11. Dental Identification is Used
Identify human remains that cannot be
identified using face recognition,
fingerprints or other means
Identify bodies in mass fatalities, such as
plane crashes and natural disasters
Determine the source of bite mark
injuries, in cases of assault or suspected
abuse
Estimate the age of skeletal remains
Testify in cases of dental malpractice

12. 1. Routine identification
unknown human remains in various stages of decomposition.
Analyze the dentition of the deceased. Record all the restorations, anomalies, missing
teeth
Radiographic and photographic records of the dental arches.
2. Mass Disasters
Identification of people in mass disasters.
3. Bitemark evidence
Identification, examination & evaluation of bite marks – sexual assaults, child abuse,
personal defense situations.
Role of Forensic Odontology

13. 4. Civil Litigation
Examination of patients sustaining trauma due to accident, assault, negligence or
malpractice – supported with radiographs, photographs etc.
5. Age Estimation
Estimation of both the living and the deceased.
6. Sex Determination
Determining the gender of unidentified individuals.
7. Other methods of Identification
Cheiloscopy (Study of lip prints)
Rugoscopy (Study of palatal rugae patterns)
Sialochemistry (Detection of Chemicals in Saliva)

14. Dental Identification Kit
PROTECTIVE CLOTHING DENTAL INSTRUMENTS
RECORDING THE DATAIMPRESSION MATERIALS
PHOTOGRAPHY

15. There are three main forms of dental identification
• Comparative Identification
• most frequently performed examination
• to establish the remains of a decedent and a person represented by ante
mortem records are of the same individual.
• Reconstructive Identification - Dental profiling or Post-mortem Dental
profile
• elicit race, gender, age & occupation of the dead individual
• undertaken when ante-mortem records are not available.
• Identification in mass disasters
• identification of victims in mass disasters
Forms of Dental Identification

16. I. Comparative Dental Identification
Conventional method of identification includes four steps
A) Oral Autopsy
• dissection to expose the organs, to determine the cause of death
• oral examination – essential part
B) Obtaining Dental Records
• Contains information of treatment & dental status during his/her life.
• Obtained from treating dentist, specialist or hospital records – in the form
of dental charts, radiographs, casts & / or photographs
C) Comparing post and ante-mortem dental records
• Compared by written notes, Study casts, radiographs, Photographs etc.,
D) Writing a report & drawing conclusions

17. Most Common Points for Comparison Include
1. The no. of teeth – Missing, impacted, supernumerary
2. Restorations & Prosthesis – Tooth no., surfaces involved, dental materials used
- type of material, no. of replaced teeth.
3. Dental Caries – Surface & configuration
4. Malposition & Rotation
5. Anomalous tooth formation – extra cusps, peg-shaped incisors, fused teeth
6. Root canal therapy – Type of filling material used, imperfections of the canal

18. II. DENTAL PROFILING
[Reconstructive identification (or) post – mortem dental proile]
It includes the decedent’s
A. ETHNIC ORIGIN [Race determination]
B. GENDER [Sex determination]
C. AGE [Age estimation]
A. Race determination:
The quality and type of dental treatment may indicate an individual's country of residence: a) Dental
treatment of high quality, which is consistent with North American and European standards. b)
Unusual dental treatments involving the use of permanent acrylic and stainless steel crowns. This
treatment was performed in Russia

19. B. Sex Determination:
Generally teeth are smaller in females
Teeth – used for differentiating sex by measuring mesiodistal & buccolingual
dimensions
Canines – show max. sex difference
Mand. Canines show greatest dimensional difference, being larger in males
SEX DETERMINATION BY DNA ANALYSIS
a. From pulp tissue:- Y chromosome analysis from dental pulp of male can be
done even after 1yr. of death
b. From enamel protein [Amelogenin]:-
Amelogenin[AMEL] – Major matrix proteins secreted by the ameloblasts of
the enamel
AMEL gene located on X & Y – chromosomes in humans
c. From Buccal Mucosa:- Barr bodies & x-chromosomes of female
detected from buccal mucosal epithelium.

20. C. Age Estimation:
Important Subspeciality of forensic sciences
Also has application in living individuals
Dental Age Estimation Methods
a. Morphologic / visual Examination
b. Radiographic Examination
c. Histological Examination and
d. Biochemical Examination
The determination of D- and L-aspartic acid (Asp) content from teeth has been
applied in age estimation for forensic purposes over the past decades.
It was first introduced to assess age from tooth enamel and later from dentin.

21. III. Identification of mass disaster
Disasters: refers to natural calamities such as earthquakes, floods
and tsunami and accidental or man-made events such as
airplane crashes or terrorist attacks-that result in multiple
human fatalities. Such incidents require identification of the
post-mortem remains due to severe mutilation.

22. Identification from Dental DNA
Teeth - Excellent source of DNA
PCR (Polymerase chain reaction)
– amplifies highly degraded DNA
compared with ante-mortem sample of the decedent (hair from a hair brush,
epithelial cells from a tooth brush or a biopsy specimen)
Major Advantage:
– DNA Pattern may be compared to a parent or a sibling, if ante-mortem sample
is unavailable.
Types of DNA
1. Genomic or Nuclear DNA – Commonly used
2. Mitochondrial DNA (mt DNA) – substituted if nuclear DNA is unavailable

23. Genomic DNA
• Genomic DNA is found in the nucleus of each cell and represents the
DNA source for most forensic applications, (there are no nuclei, and
hence there is no DNA, in red blood cells.)
• When body tissues have decomposed, the structures of the enamel,
dentine and pulp complex persist.
• It is necessary to extract the DNA from the calcified tissues. the
cryogenic grinding method is best employed for DNA extraction.

24. Extraction of Dental DNA
CRYOGENIC GRINDING –
Coding the whole tooth to
extremely low temp., using
liquid nitrogen & grinding it
to fine powder.
Major drawback is tooth
needs to be completely
crushed.
Less destructive method is
drilling the root canals &
scraping the pulp area. Cryogenic grinding is used to extract DNA from calcified tissues such as teeth. In a freezer
mill a ferromagnetic plunger is oscillated back-and-forth in alternating electric current.
Liquid nitrogen is used to cool the sample, which results in making it extremely brittle and
also protects DNA from heat degradation. The tooth is reduced to a powder to increase
surface area and expose trapped cells to biochemical agents that release DNA into solution

25. Bite Marks
Impressions from teeth found on skin or items left
at a scene. Usually outline teeth placement.

26. Need for dental identification
• Decomposing remains
• Skeletonized remains
• Charred remains
• Doe Identification ; Intact remains without any putative victim
• Scientific verification of identity is anticipated
• Multiple bodies recovered from a common location
• Mass disaster
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27. Analyzing bite marks
 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

28. Site 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
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29. Various Bite Marks

30. Computer Odontology
 Automatic dental code matching
Bites are run through the computer to find a match
 OdontoSearch
Compare a data base of missing peoples, felons, government
workers
 Automatic dental identification system
A few minutes will produce a list of people who have the same
dental code number
 3D Bite mark analysis
3D scans of dental casts are used to generate overlays using
various pressure and deviation.
The overlays are compared with the photograph of the bite marks.

31. Classification of bite marks
1. Cameron and Sims Classification
based on the type of agent producing the bite mark and the
material exhibiting it.
• Agents
• Human
• Animal
• Materials
• Skin, body tissue
• Foodstuff
• Other materials.

32. 2. MacDonald's Classification.
suggested an etiologic classification.
• Tooth pressure marks: Marks produced on tissue as a result
of "direct application of pressure by teeth". These are generally
produced by the incisal or occlusal surfaces of teeth.
• Tongue pressure marks: When sufficient amount of tissue is
taken into the mouth, the tongue presses it against rigid areas
such as the lingual surfaces of teeth and palatal Rugae. The
marks thus left on the skin are referred to as 'suckling,' since
there is a combination of sucking and tongue thrusting
involved.
• Tooth scrape marks: These are marks caused due to scraping
of teeth across the bitten material. They are usually caused by
anterior teeth, and present as scratches or superficial
abrasions.

33. Tooth and tongue pressure marks
Bite marks on cheese

34. 1. Odontometric triangle method
• In this objective method a triangle is made on the
tracing of bite marks and teeth models by marking three
points, two on the outer most convex point of canines
and one in the centre of the upper central incisors.
• Three angles of the triangles are measured and
compared.
• A clinico-anthropological study carried out by
Manohar Singh et al by comparing bitemark width,
bizygomatic and bigonial width concluded that from a
given bitemark impression the facial dimensions of a
person who is responsible for the mark can be
determined
Methods of Analysis of Bite Marks

35. 2. Rugoscopy - The palatal rugae in identification
Useful method in edentulous individuals
Rugae pattern – unique to an individual.
• The rugae pattern on the deceased's maxilla or maxillary denture may be
compared to old dentures that may be recovered from the decedent's
residence or plaster models that may be available with the treating dentist.

37. Rugae Pattern

38. 3. Cheiloscopy - Examination of lip prints
• Cheiloscopy is a forensic investigation technique that deals with
identification of humans based on lips traces.
• Lip prints have to be obtained within 24 hours of time of death to
prevent erroneous data that would result from post mortem alterations
of lip.
• Lip print pattern depends on whether mouth is opened or closed.
• In closed mouth position lip exhibits well defined grooves, where as in
open position the groves are relatively ill defined and difficult to
interpret

40. • Lip prints are usually left at crime scenes and can provide a direct link to the
suspect.
• Traditionally, the use of lipsticks was essential to leave behind colored traces of lip
prints.
• In recent years, however, lipsticks have been developed that do not leave any visible
trace after contact with surfaces such as glass, clothing, cutlery or cigarette butts.
• Nevertheless, these lipstick marks are characterized by their permanence and
produce 'persistent' lip prints that can be recovered days after being produced.
• Although invisible, Alvarez and associates have shown that these prints can be
developed and visualized using agents such as aluminium powder and magnetic
powder.
• It is also interesting to note that the use of lipsticks is not indispensable for leaving
lip prints.

41. 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 something else.
•• 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 excluded.
•• criteria: pattern conclusively illustrates
(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 dentition.
Inference
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42. Oral findings of child abuse/maltreatment
Findings Cause
Multiple broken, discolored, missing or avulsed teeth Repeated episodes of mouth trauma
Peculiar malocclusions & non occluding jaw segments Healed jaw fractures which were displaced
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
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43. • In one study,the lips were the most common site for inflicted oral injuries
(54%), followed by the oral mucosa, teeth, gingivae, and tongue.
• Discolored teeth, indicating pulpal necrosis, may result from previous
trauma.
• Gags applied to the mouth may result in bruises, lichenification, or scarring
at the corners of the mouth.
Tear of labial frenum Trauma to lipFracture of tooth

44. • The roles of any forensic scientist are to collect, preserve and interpret
trace evidence, then to relay the results to the judicial authority in a form
of a report.
• Forensic Odontology is the forensic science that is concerned with dental
evidence.
• Dental practitioners should be aware of the forensic application of
dentistry.
• Dental records that are used to provide patients with optimal dental
service could also be very beneficial to legal authorities during an
identification process.
• Therefore, all forms of dental treatments should be recorded and kept
properly.
Conclusion

45. • "Forensic Odontology." Monkeyshines on Health and Science 2003: 14.
• Graves, Chris. Sorting out a mouthful of clues. Minneapolis: Star Tribune, 2000.
• Lotter, Karen. Taking a look at Human Bite Marks. 2008. 27 November 2010
<www.asfo.org/news>.
• McRoberts, Flynn and Steve Mills. Testimony on Bite Marks Prone to Error. Chicago: Chicago
Tribune, 2004.
• Weigler, S. "Bite Mark Evidence: Forensic Odontology and the Law." Journal of Law Medicine
(1992): 303.
• Bowers CM. Forensic Dental Evidence: An Investigator's Handbook. San Diego, Calif: Academic
Press; 2004.
• Dorion RBJ, ed. Bitemark Evidence. New York, NY: Marcel Dekker; 2005.
• Fixott RH, ed. The Dental Clinics of North America (Forensic Odontology).Philadelphia, Pa: WB
Saunders Company; 2001:45(2).
References