INTRODUCTION TO FORENSIC ODONTOLOGY- PART 1

Word “Forensic”- latin word Forum means “Court of Law”.
FDI defines it as that branch of dentistry which in the interest of justice, deals with the proper handling and examination of dental evidence and with the proper evaluation and presentation of dental findings.
Forensic Odontology is the application of dentistry in legal proceedings deriving from any evidence that pertains to teeth.

1. FORENSIC FORENSIC
ODONTOLOGYODONTOLOGY
PART-1PART-1
Dr. Maya S
Reader
Dept of Oral and
Maxillofacial Pathology

2. CONTENTS- PART-1
INTRODUCTION
HISTORY
DENTAL IDENTIFICATION
UNCONVENTIONAL IDENTIFICATION
DISASTER VICTIM IDENTIFICATION
DENTAL PROFILING
GENDER DETERMINATION

3. CONTENTS PART-2
DENTAL AGE ESTIMATION
CRIME INVESTIGATION-BITE MARKS

CHILD ABUSE

4. Forensic OdontologyForensic Odontology
•Word “Forensic”- latin word Forum means “Court of Law”.
•FDI defines it as that branch of dentistry which in the
interest of justice, deals with the proper handling and
examination of dental evidence and with the proper
evaluation and presentation of dental findings.
•Forensic Odontology is the application of dentistry in legal
proceedings deriving from any evidence that pertains to
teeth.

5. Scope of Forensic Odontology
1.Identifying unknown human remains through
dental records & cranio-facial bones
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.Identification in mass fatalities
7.Eliciting the ethnicity from the skeletal remains
8.Analysis of dental malpractice claims
9.Presenting evidence in court as an expert
witness

6. Historic mile stones in forensic dentistry
• 1st dental identification was made between 49-66 AD

• King William ; in 1066 AD was supposed to be the 1st to use
bite marks for identification .
• 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”

7. History of Forensic Odontology
•66AD – First body identified using teeth-
Lollia Paulina
•Revolutionary War-Paul Revere was the first
forensic dentist in the United States
because he identified fallen revolutionary
soldiers.
•1849 – Mass deaths at Vienna Opera House
Fire-Dental evidence was first admitted into
court system in US.
•In 1967 Russian source reported that dental
evidence was responsible for identification
of badly charred bodies of Adolf Hitler &
Eva Braun.

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

9. IDENTIFICATION??
Identification is the establishment of person’s
individuality.
Requirement for proper identification of dead:
1.Both for legal and humanitarian reasons.
2.Property settlement.
3.Remarriages.
4.Allow cremation and burial of the body.

10. TRADITIONAL MEANS OF IDENTIFICATION
Visual recognition
Personal property
Anthropometry
Serology
DISADVANTAGES:
These methods are presumptive
Present a series of general characteristics
May not be unique

11. Safest option for identification is to analyze
physical features present in body.
Physical features may be inherited or acquired.
Inherited features include racial characteristics.
Acquired features may be surgical scars, previous
fractures or dental restorations.

12. Dental Identity??
According to Acharya and Taylor,
the Dental identity is defined as total
of all the characteristics of teeth and
associated structures which while not
individually unique, when considered
together provide a unique totality.

13. DENTAL IDENTIFICATION
Why Teeth???
•Every human body ages in a similar manner, the teeth also follow a
semi-standardized pattern. These quantitative measurements help
establish relative age of person.
Each human has an individual set of teeth which can be traced back
to established 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 helps to identify a person.
The positive identification of living or deceased persons using the
unique traits and characteristics of the teeth and jaws is a corner
stone of forensic odontology

14. Individual Characteristics
Size of tooth
Shape of tooth
Shape of root
Placement of tooth
Number of teeth
Combinations of dental
work done:
Crowns
Extractions
Bridge
Fillings
Root canals
Various dental work

15. Basis for Dental Identification
•Human dentition is never same in any two
individuals
•The morphology and arrangement of teeth vary
from person to person
•Teeth are relatively resistant to environmental
insults after death

16. Dental Identification Procedures
Two forms:

17. Comparative Dental Identification
Includes four steps:

18. POSTMORTEM DENTAL EXAMINATION
It is conducted at mortuary under the authorization of
forensic medical examiner.
First step is visual appraisal of the dead body.
The body bag should be searched thoroughly for any teeth
or appliances.
All the features like missing, caries ,restorations, attrition,
rotation and occlusion should be recorded and entered in
Interpol Postmortem dental form.

19. Systematic protocol starting with critical examination of
the external features of the body such as gender,
ethnicity, build, wounds, scars, tattoos and body
piercing.
 Photographs, radiographs, finger prints, fingernail
scrapings and hair sample are then collected.
Oral examination is an essential part of the post mortem
procedure. The forensic dentists who conducts oral
autopsy should have adequate knowledge about common
post mortem findings such as Rigor mortis, Livor mortis,
Decomposition, and post mortem artifacts.

20. Rigor Mortis is a state of stiffening of muscles render the
jaws rigid and the use of mouth gags or intra oral
myotomy is essential for jaw separation.
Teeth may become brittle in burned cases, they need to
be reinforced with Cyanocrylate cement, polyvinyl
acetate or clear acrylic spray paint prior to examination.
According to Griffith and Bellamy, access for radiography
in incinerated bodies can be obtained by removing tongue
and floor of the mouth by tunneling fashion from beneath
the chin.

21. A thorough examination of soft tissue injuries,
fractures and presence of foreign bodies is under
taken and samples of hard and soft tissues should
be obtained
All post mortem information pertaining to the body
must be entered on to the standard ‘Interpol Post
mortem Form’ which is color coded in pink.

22. OBTAINING ANTE-MORTEM (AM)
RECORDS
Dental records contain information of
treatment and dental status of a person
during his / her life
 may be obtained from the treating dentist,
specialist or hospital records.
Original records should be examined.
Such records may be in the form of dental
charts, Radiographs, casts, photographs,
etc.,
The contents of all available dental records
should be transcribed onto the standard
‘Interpol Ante-mortem Form’ which is color
coded in yellow.

23. COMPARING POST AND ANTE -MORTEM
DENTAL DATA
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
restorations
An individual with multiple dental
treatment and unusual features has
a better likelihood of being identified
Comparison should be qualitative
rather than quantitative in nature.

24. REPORT AND CONCLUSION
On comparison of AM and PM data, a range of conclusions
can be reached:
Positive identification
- indicates that AM and PM data match each other
-Identity is proven “beyond reasonable doubt”.
-It usually includes radiographic support.
Probable identification
-Where the data is consistent but a lack of quality PM/AM
information means one cannot arrive at a positive
identification.
-There is high level of concordance between AM and PM
information but usually no radiographic support.

25. Possible identification
-wherein the available information is
insufficient for a positive identification but
the identity cannot be excluded either.
Exclusion of identity
-In which AM and PM data are clearly inconsistent.
-The data contains unexplainable differences that
indicate a mismatch.

26. UNCONVENTIONAL IDENTIFICATION
Where comparative dental identification is not possible these
may be applicable:

27. SKULL SUTURE PATTERNS
-Patterns produced by cranial sutures are highly variable and
individualising.
-Sutures commonly used for identification are the coronal,
saggital and lambdoid.
-Various sutural configurations:
Serrated
Denticulate
Squamous
Limbous
Plane
Visible on routine diagnostic radiographs
such as antero posterior , lateral views

28. 2. FRONTAL SINUS CONFIGURATION
-Insignificant during early stages of life
-Increases in size and complexity with age and
attains max size at abt 20 years
3. FACIAL RECONSTRUCTION
-A 3-D representation of facial structures is
produced using the skull as the foundation.
-Skull cavities are blocked with modelling wax.
-Impression of skull is made with rubber base
impression materials and cast is poured with plaster
-Disadvantages:
- time consuming
-variable success rate
- highly subjective

30. Superimposition methods
When lack of dental records is there, superimposing the
facial photograph and skull has been advocated
Since anterior dentition is usually visible, use of tooth size,
shape, angulations may be of particular relevance
Photographic superimposition
Disadvantages:
-angular positioning-the skull and the facial image should
have reasonably equal horizontal and vertical angulations.
-Camera object distance- differences in the focal lengths of
camera lens can alter the contour of high curvature areas
--poor initial photography-inferior camera and film quality
can result in poor quality photographs.

31. VIDEO SUPERIMPOSITION
Advantage over photographic superimposition
Positon of the skull can be altered
Video mixers enable added advantage of fade-in, fade-
out horizontal and vertical “sweep” mechanisms.
It allows different images to be progressively
superimposed upon each-other

32. DIGITAL SUPERIMPOSITION
Newer trends used.
AM photographs is digitised to produce a 2-D image
Skull is laser scanned to produce 3-D image
The 2-D digitised AM image is then projected onto the 3-D
skull image and the anatomical landmarks are compared.

33. LIP PRINTS
Examination of lip prints- “cheiloscopy”
The lines and fissures of the lips have individual
characteristics similar to fingerprints
Can be used in identification
Genetically determined
Remain unchanged from birth
Tsuchihashi named the wrinkles and grooves on lips-
“sulci labiorum rubrorum”

34. CLASSIFICATION
- Lip prints were first classified by Santos as:
a) Simple wrinkles
Straight line
Curved line
Angled line
Sine-shaped curve
b) Compound wrinkles
Bifurcated
Trifurcated
Anomalous

35. According to Tsuchihashi :

Type I- Clear- cut vertical grooves that run across the
entire lip
Type I’-Similar to type I, but do not cover the entire lip
Type II- Branched grooves
Type III- Intersected grooves
Type IV- Reticular grooves
Type V- Grooves that can not be morphologically
differentiated

36. -Invisible prints can be lifted using materials such as
aluminum powder, magnetic powder
DISADVATAGE:
1.Trauma, pathosis, surgical treatment can affect the
size and shape of the lip
2.The zone of transition close to vermilion border is
extremely mobile so prints produced may differ
depending on pressure applied and its direction

37. Different Patterns of Lip Prints
Lip Prints.(Cheiloscopy),IJDR,10: 234-237,2001.

38. PALATAL RUGAE
Examination of Palatal Rugae- “Rugoscopy”.
Palatal Rugae are well protected by the lips,
cheeks, tongue and the teeth in incidents of fire
and high impact trauma.
Rugae patterns do not change with age and
reappear after trauma or surgical procedures.
They may be a reliable source of identification,
especially in cases of edentulous individuals.

39. CLASSIFICATION
Given by Lysell, based on length:
1.Primary rugae (>5mm)
2.Secondary rugae (3-5mm)
3.Fragmentary rugae (2-3mm)
(<2mm is not taken into consideration)
By Kapali and associates, based on shape:
1.Straight
2.Wavy
3.Curved
4.Circular

40. According to Thomas and Kotze:
1.Branched
2.Unified
3.Cross-linked
4.Annular
5.Papillary

42. SCANNING ELECTRON MICROSCOPY
Used for detailed study of surface configuration , tooth
morphology , fracture surfaces and restorations.
Provides a highly magnified, 3-D image of minute surface
structures.
In one case- SEM detected micro serrations produced by
dental drill in an incinerated tooth- establishing presence
of a prepared cavity.
Presence of fissure sealant in another case- assisted in
positive identification of individual.

43. DNA ANALYSIS
Teeth are excellent source of DNA material.
DNA is made use only when conventional dental
identification fails.
PCR allows for amplification of DNA-popular with forensic
investigators.
DNA extracted from teeth of a deceased-compared with
known AM sample, to a parent or sibling.
AM sample- stored blood, hairbrush, biopsy specimen.

44. Precise method for identification
Very time consuming and expensive process
Very technique sensitive with contamination problems
Usually match victim samples with samples taken from
personal items or from known relatives
Essentially 2 types of DNA:
-Nuclear DNA
-Mitochondrial DNA

45. Nuclear DNA commonly used-
forensic cases.
Method to obtain genomic DNA from
teeth- “cryogenic grinding”.
 mitochondrial DNA(mtDNA)has an
advantage –each cell has a high
number of mitochondria ,so high
mtDNA
Hence can be substituted when
nuclear DNA is unavailable.
Cryogenic grinding

46. mtDNA is maternally inherited, thus same DNA
pattern observed among maternal relatives.
Due to exclusive maternal inheritance, can be used
in identification in gap of several generations.

47. DNA EXTRACTION :
Proposed by Sweet and Hilderbrand
1.CRYOGENIC GRINDING:
The whole teeth is subjected to extreme low
temperature using liquid nitrogen and then
grinded.
Disadvantage: whole teeth is lost.
2.Proposed by Trivedi and associates
DNA was isolated by opening root canal and
extirpating the pulpal tissue with some instrument
and DNA was extracted.
Advantage: tooth morphology is preserved .

48. DISASTER VICTIM
IDENTIFICATION
Disasters refer to events natural (earthquakes ,tsunami,
floods, landslides) or manmade (air crashes, train
accidents) that result in multiple human fatalities.
 Such events require identification of the individual due to
severe mutilation of remains.
Dentition being more resistant structures aid in
establishing identity.
It includes comparing hundreds of AM and PM data.

49. MAJOR PROBLEMS
Some major problems encountered in a
disaster include:
Large number of human remains
Fragmented, commingled, burned
remains
Insufficient PM remains
Acquiring relevant dental records
Legal, jurisdictional and political
issues
Less organization and communication

50. Forensic dentists along with fingerprint experts and
other identification teams are part of the identification
commission.
 Dental identification is one of the most successful
methods of identification in disasters, approximating
50% .
Therefore, most disasters have a DVI dental section .
The DVI dental section is divided into three sub-
sections:
1. Ante- Mortem dental unit.
2. Post- Mortem dental unit
3. Dental comparison unit

51. Ante Mortem Dental Unit
TASKS OF AM UNIT
They need to collect as much information as
possible in shortest period of time.
Determine who is involved in disaster.
Locate and procure ante mortem records.
Develop an AM composite for each victim.

52. Personnel in this unit should be capable of reading
and interpreting all dental records provided.
 The quality, quantity, and variety of dental
record present the major obstacle to this unit.
 Transcribing and copying could reduce the
quality of AM information.
 All information obtained must be transferred
onto a standard (INTERPOL)AM form.

53. Post Mortem dental unit
The dental examination is done usually after most other
procedures (general photography, fingerprinting, medical
autopsy, etc), which gives sufficient time to set up base.
Equipment such as portable dental radiography apparatus
should be set up at a convenient place within the
temporary mortuary
 Need to arrange for photography of teeth.
 This unit will also be responsible for processing of
radiographs.

54. DENTAL COMPARISON UNIT
Comparison and identification should begin once all the
PM information is available.
 It may be done manually or by computer aid.
Computer software programs such as
IDENTIFY,ODONTID, TOOTHPICS,CAPMI etc, can be used.
The final identification is always done by the dentist, based
on personal evaluation of evidence.
The INTERPOL guide states that the success of DVI
depends upon the active participation of different
identification teams. Therefore, its reciprocal in nature
and adds to the SUCCESS of DVI.

55. DENTAL PROFILING
-Triad of information
ETHNIC ORIGIN
GENDER
AGE

56. ETHNIC ORGIN
Human
species
Sub-saharan-negroid
Sahul-pacific
Australians,fiji
Western Eurasia-
Europe,middle
east
Sunda-pacific
South east
asia,new-zealand
Sino-american-
mongoloids
North east asia
S America

57. Dental features
 Metric features –tooth size(eg-lack of
space in jaw leads to compressed teeth)
 Non metric features-tooth shape
NON METRIC FEATURES- “Shovelling”
HIGH-Sino-american
INTERMEDIATE-Sunda pacific
LOW-others
“Carabelli’s” feature-
High-Western eurasia
Low-Sino american
Intermediate-others
Shovel-shaped incisors and the Cusp of
Carabelli are both dental indicators for ethnicity

58. More than 30 non metric features- Richard Scott and
Christy Turner II.

59. European / West &
South Asians-
4 cusped lower-2
nd

molars,
 Two rooted-Lower
canine,
 3 cusped upper
2
nd
molar
East Asians-
•Shovelling,
•3 rooted lower 1
st

molars,
•3 cusped upper-2
nd

molars
•Single rooted
lower 2
nd
molars

60. GENDER DETERMINATION
Determining the gender from unknown skeletal remains -
2
ND
step in building the dental profile of the deceased.
Gender determined from :
- METRIC FEATURES OF THE TEETH
- MORPHOLOGY OF SKULL BONES AND MANDIBLE
- DNA ANALYSES OF TEETH

61. METRIC FEATURES OF TEETH
Teeth maybe used for differentiating gender by
measuring their MD and BL dimensions.
Male teeth are larger.
Studies show significant differences between male
and female permanent tooth crown dimensions.
Tooth measurements are population specific and
vary from region to region.

62. The canines have maximum differences in most studies.
Anderson and Thompson 1973, observed that mandibular
canine width and inter-canine distance were greater in
males than females and permitted a 74.3% correct
classification of gender.
Hence regarded as most “dimorphic teeth”.
Female canine are narrower BL and more pointed.

63. DENTAL INDEX
 In relation to absolute tooth size, tooth proportions have
been suggested for differentiating between males and
females.
RAO and associates developed “MANDIBULAR CANINE
INDEX”.
Aitchison presented the “INCISOR INDEX”
-Ii= [MDI 2/MDI 1] X 100,
- where MDI 2 is maximum M-D diameter of lateral incisor.
-MDI 1 is maximum M-D diameter of central incisor.

64. Mean and standard deviation (SD) of MCI was derived
separately for males and females and a cut off point to
distinguish the gender, termed STANDARD MCI was
calculated:
[(mean m-d canine dimension in female+ S.D.)+
(mean m-d canine dimension in males-S.D.)] / 2
Standard MCI value –acc to RAO and associates was
0.274
If the MCI value of skull specimen less than or equal to
standard MCI -female
If more-male
Success rate-86%

65. MORPHOLOGY OF SKULL BONES
Orbits- squared,


rounded marginsNasion-depressed
Size is larger
MALE FEMALE
Smaller size
Slightly developed
Rounded,sharp
margins
Rarely depressed
Supraorbital
ridge-well
developed

66. •Glabella-markedly
curved
•Mastoid process-large

•Forehead-sloping
•Nasal aperture- High
and narrow
•Palate-large,U-shaped
•Foramen magnum-large
and long
•slightly curved
•Small
•Straight
•Low and broad
•small,parabolic
•small and round
MALE FEMALE

67. MANDIBULAR FEATURES
Bigger, broader
ascending ramus

Condyle-larger
Shape of chin-
square
Gonial angle-less
obtuse
Body height-
greater depth at
symphysis
 smaller, narrow
ascending ramus
smaller
rounded or
pointed
more obtuse
shallow
MALE FEMALE

68. GENDER DETERMINATION BY DNA
ANALYSIS
Amelogenin (AMEL)-major matrix protein secreted
by ameloblasts of enamel.
AMEL gene is located on X and Y chromosome in
humans.
It has a different signature with size and pattern of
nucleotide sequence in males and females.
Females-XX have 2 identical AMEL gene
Males-XY have 2 non-identical genes.
(Hanaoka and Minaguchi 1996)

69. Sex determination using Barr Bodies
Barr et al 1950, the X-chromatin and intranuclear
structure is known as Barr body.
It is present as a mass usually lying against the nuclear
membrane in females.
Up to period of 4 weeks after death,gender determination
can be accurately done from study of X and Y
chromosomes.

70. Whittaker et al 1975, reported gender
determination from necrotic pulp tissue stained by
quinacrine mustard using a fluorescent Y-
chromosome test, can be done with high accuracy.
Duffy et al 1991, showed Barr bodies of X-
chromosome and F bodies of Y-chromosomes can
be preserved in dehydrated pulp tissues and that
these pulp tissues retain their gender diagnostic
characteristics for a minimum of 1 year.

71. REFERENCES
Forensic Odontology-Paul G Stimson
Textbook Of Oral Pathology-Shafers
Oral And Maxillofacial Pathology-Neville
Evidence Based Forensic Dentistry- Balwant Rai
and Jasdeep Kaur
A look at forensic dentistry —Part 1: The role of
teeth in the determination of human identity.
British Dental Journal, volume 190, no. 7, april 14,
2001.