1. ROLE OF DENTAL
RADIOGRAPHY
IN FORENSIC
ODONTOLOGY

2. INTRODUCTION

3. What is Forensic Science?
• …the application of
science to those
criminal and civil
laws that are
enforced by police
agencies in a
criminal justice
system.

4. Forensic Science is…
• Applied science
• Often called
“criminalistics”

5. Forensic Science applies
• Chemistry
• Biology
• Physics
• Geology
to civil and criminal law.

6. Definition of Forensic Dentistry
Forensic dentistry, or
forensic odontology, is the
application of dental and
paradental knowledge to the
solution of legal issues in
civil and in criminal matters.

7. The THEORY behind forensic
dentistry is that no two mouths
are alike (even identical twins
are different), and that teeth,
like tools, leave recognizable
marks.

8. Identification by teeth is not new.

9. During the U.S. Revolutionary War, none other
than Paul Revere (a young dentist) helped
identify war casualties by their bridgework.
Teeth are highly resistant to destruction and
decomposition, so dental identification can be
made under extreme circumstances.(1600ºC)
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.
Identification by teeth is not new.

10. THE MAIN ASPECTS OF FORENSIC
ODONTOLOGY INCLUDE:
1. Dental identification
2. Age estimation
3. Sex determination
4. Role in mass disasters
5. Role in domestic violence, abuse and
neglect
6. Identification of bite marks
7. Blood group determination
8. Recent advances: DNA typing, computer
assisted dental identification, , digital
analysis of bite marks, digital autopsy

11. METHODS OF IDENTIFICATION
1. Comparative Dental Identification
2. Reconstructive Postmortem Dental
Profiling
3. DNA Profiling

12. RADIOGRAPHY OF
POSTMORTEM MATERIAL

13. Radiography may have to be carried out in
the field or at the scene of autopsy.
This may require certain modifications in
the normal procedures followed, requiring
the operator to adapt techniques to
individual cases and here the ability to
think laterally is an essential requirement
of the forensic odontologist.

14. EXPOSURE TIME FOR BITE-WINGS AND
PERIAPICAL VIEWS
TIME
kVp mAs Anode-film
distance (cm)
D-speed film
(s)
E-speed
(s)
50 7.5 10 0.5 0.25
60 10 20 0.6 0.3
70 10 20 0.3 0.15
80 15 40 1.0 0.5

15. EXPOSURE TIME FOR OCCLUSAL
TECHNIQUES
kVp mAs Anode-film
distance (cm)
TIME
(s)
50 7.5 20 1.0
60 10 30 1.0
70 10 30 0.5
80 15 40 0.75

16. EXPOSURE TIME FOR MAXILLOFACIAL
VIEWS
View kVp Time
(s)
mAs
PA, Townes
Jaws 65 0.3 30
Lateral
Jaws 55 0.3 30
Vault 0.6 60
OM 65-75 0.3 30

17. Density of the object: Ranges from
• very low density specimens due to
fire,
• or perhaps remains of an early fetus,
• through specimen in varying stages of
decalcification,
• to waterlogged skull at the other
extreme.

18. X-ray apparatus and the X-ray beam:
Ideally variable kVp apparatus is
recommended.
Kilovoltage:
Low kilovoltages are essential for
specimens such as early fetus and can be
an advantage for dry dental specimens.
For fresh, complete skull is to be
radiographed, kilovoltages of 65-75 kVp
are to be preferred.

19. Milliamperage:
Dental apparatus operates with a low
milliamperage to allow for easy movement
of the tube head.
Time is not a problem in the forensic field
as the object will not move and the
exposure timer can simply be reactivated.
Distance:
If a large field of irradiation is required to
cover a larger specimen, then the anode-
object distance must be increased.
Field of irradiation:
An X-ray apparatus with an adjustable
diaphragm should be used.

20. AUXILIARY EQUIPMENT
1. Tape measure
2. Radiographic measure
3. Rigid, clear plastic surface
4. Plastic foam pads of different shapes
5. Sand bags, dental wax and cotton rolls,
for fine immobilization.
6. Plastic bags and rubber gloves
7. ‘R’ and ‘L’ lead letters
8. Small manual processor for field work.

22. ANTEROPOSTERIOR VIEW
Place the cassette, protected by plastic
under the skull and position the tube as far
away as possible from the cadaver.
The X-ray beam should be parallel to the
orbitomeatal line, so in most cases the X-
ray tube should be angled downwards
from the vertex.

24. LATERAL VIEWS
Place the cassette supported by sand
bags parallel to the sagittal plane.
Raise the skull above the table, insert a
polystyrene foam pad or wooded block
underneath.
Turn the X-ray tube head so the X-ray
beam is parallel to the floor and centered
over the skull towards the cassette.

26. OCCLUSAL TECHNIQUES

27. OBLIQUE LATERAL VIEW
The cadaver is rotated so that the
premolar or molar region is obliquely
placed- enough to allow the tube head to
be angled upward and forward from the
lateral position.
In the mortuary the cadaver must be
raised with a radiolucent substance such
as wood or plastic foam.

30. Skull placed on the inclined wooden plane
adapted to the chassis holder of the
teleradiography x-ray machine to make lateral
oblique radiographs of the mandible for angle
and body

31. Lateral oblique radiograph of a mandible
for angle and body obtained with the same
positioning as the previous figure

32. TOWNES TECHNIQUE
• This view is taken for the neck of the
condyles.
• It may be taken as a Reverse Townes
view with skull PA.
• Position of the head: Back of the head to
the film.
• Orbitomeatal line: 90o to the film.
• X-ray beam: 30o to the orbitomeatal line.
• Centering point: 5 cm above the nasion.

34. OCCIPITOMENTAL TECHNIQUE
• This is a routine view taken for the
maxillary and frontal sinuses and is always
in the PA position.
• Position of the head: Orbitomeatal line 45o
to the horizontal and film-sagittal plane.
• X-ray beam: vertical.
• Centering point: 5 cm above the occipital
protuberance.

36. INTRAORAL TECHNIQUES
• X-ray beam: vertical angle is varied
according to the antemortem radiograph,
in order to obtain the most plausible and
approximated comparative image.
• Support used: Han Shin positioner to hold
the film

38. COMPARISON RADIOGRAPHY

39. • Antemortem radiographs of the deceased
which may have been taken during routine
dental treatment should be compared with
that of postmortem radiograph taken at the
time of investigations.

43. Photographic comparison of morphology, size and shade
of teeth, occlusion and midline deviation

44. Radiographic comparison of restorative
endodontic treatment morphology in (A) postmortem
and (B) antemortem

45. AGE ESTIMATION

46. EACH PERSON ACTUALLY HAS
MORE THAN ONE AGE
• Pathologic age:
– This is related to the various conditions and
disease processes that result in deterioration of
many tissues over time.
– It can be estimated by examining factors such
as arthritic changes in the temporomandibular
joints, attritional wear of the teeth and root
dentine transparency.

47. EACH PERSON ACTUALLY HAS
MORE THAN ONE AGE
• Physiologic age:
– This is determined by natural expected changes
that occur through growth and development.
– Maturation is scaled by occurrence of one or
the sequence of multiple events that are
irreversible.

48. EACH PERSON ACTUALLY HAS
MORE THAN ONE AGE
• Chronological age:
– This is the time from birth to death.
BIRTH
DEATH

49. DENTAL
AGE
Calcification
Age
Eruption
Age

50. AGE
DETERMINATION
Atlas method Scoring method

51. Prenatal,
natal &
post-natal
Children &
Adolescents
Adults

52. PRENATAL, NATAL AND POST-
NATAL AGE ESTIMATION
Radiograph of upper and lower jaws of a fetus at the
sixteenth week of intrauterine life showing the initial mineralization of
deciduous incisors

53. PRENATAL, NATAL AND POST-
NATAL AGE ESTIMATION
Diagrammatic representation of a radiograph of a
mandible of a fetus at the twenty-sixth week of intrauterine life
showing advanced mineralization in anterior teeth, outline for two
cusps of deciduous first molar, one cusp for deciduous second molar
and the crypt of permanent first molar

54. PRENATAL, NATAL AND POST-
NATAL AGE ESTIMATION
Diagrammatic representation of a radiograph of a
mandible of a fetus at the thirtieth week of intrauterine life showing
3/5 crown completion for anterior teeth, the fused cusps of deciduous
first molar, five cusps of the deciduous second molar and the crypt of
permanent first molar with no evidence of mineralization

55. PRENATAL, NATAL AND POST-
NATAL AGE ESTIMATION
Diagrammatic representation of a radiograph of the
mandible of a newborn fetus showing the completely fused
cusps for deciduous first and second molar, and within the
crypt of permanent first molar there is evidence of one mesial
cusp tip

56. PRENATAL, NATAL AND POST-
NATAL AGE ESTIMATION
• Stages by Kraus and Jordan:
Kraus and Jordan studied the early
mineralization in various deciduous teeth
as well as in the permanent first molar.
The development is described in ten
stages, denoted by Roman numerals from
I to X; the IXth stage includes three stages
and the Xth stage includes five stages.

57. AGE ESTIMATION IN CHILDREN
AND ADOLESCENTS
• Schour and Masseler method
• Moorees, Fanning and Hunt method
• Demirjian, Goldstein and Tanner method
• Nolla’s method and
• age estimation using open apices

58. SCHOUR AND MASSLER METHOD
• In 1941, Schour and Masseler studied the
development of deciduous and permanent
teeth, describing 21 chronological steps
from 4 months to 21 years of age and
published the numerical development
charts for them.

61. MOORES, FANNING AND HUNT
METHOD
• In this method, the dental development
was studied in the 14 stages of
mineralization for developing single and
multirooted permanent teeth and the mean
age for the corresponding stage was
determined.

62. 14 stages of tooth formation of multi-rooted tooth (Moorees et al). Initial cusp formation
(Ci), coalescence of cusps (Cco), cusp outline complete (Coc), crown half complete
(Cr1/2), crown three quarter complete (Cr3/4), crown complete (Crc), initial root formation
(Ri), initial cleft formation (Cli), root length quarter (R1/4), root length half (R1/2), root
length three-quarters (R3/4), root length complete (Rc), apex half closed (A1/2), apical
closure complete (Ac)

64. DEMIRJIAN, GOLDSTEIN AND
TANNER METHOD
• Demirjian, Goldstein and Tanner rated
seven mandibular permanent teeth in the
order of second molar (M2), first molar
(M1), second premolar (PM2), first
premolar (PM1), canine (C), lateral
incisors (I2) and central incisor (I1) and
determined eight stages (A to H) of tooth
mineralization together with stage zero for
nonappearance.

66. DEMIRJIAN, GOLDSTEIN AND
TANNER METHOD
• The stages are the indicators of dental
maturity of each tooth.
• The differences in the dental development
between males and females are not
usually apparent until the age of 5 years.
• Each stage of mineralization is given a
score which provides an estimate of dental
maturity on a scale of 0–100 on percentile
charts.
• The maturity scores (S) for all the teeth are
added and the total maturity score may be
converted directly into a dental age as per
the standard table given or they are
substituted in regression formula.

67. FEMALES:
MALES:

68. NOLLA’S METHOD
• Nolla evaluated the mineralization of
permanent dentition in ten stages.
• The method can be used to assess the
development of each tooth of the maxillary
and mandibular arch.
• The radiograph of the patient is matched
with the comparative figure.
• After every tooth is assigned a reading, a
total is made of the maxillary and
mandibular teeth and then the total is
compared with the table given by Nolla.

71. AGE ESTIMATION IN
ADULTS
Volume
assessment of
teeth
Pulp-to-
tooth ratio
method by
Kvaal
Coronal
pulp cavity
index
Development of
third molar
Harris &
Nortje
method
Van
Heerden
system

72. METHOD BY KVAAL ET AL
• In this method, pulp-to tooth ratio were
calculated for six mandibular and maxillary
teeth, such as maxillary central and lateral
incisors; maxillary second premolars;
mandibular lateral incisor; mandibular
canine; and the first premolar.

73. METHOD BY KVAAL ET AL
• Using intraoral periapical radiographs,
pulp-root length (R), pulp-tooth length (P),
tooth-root length (T), pulp-root width at
cemento-enamel junction (A), pulp-root
width at mid-root level (C) and pulp-root
width at midpoint between levels C and A
(B) for all six teeth were measured.

74. METHOD BY KVAAL ET AL
Diagram of premolar
showing measurement
sites:
Pulp root length (R),
pulp-tooth length (P),
tooth-root length (T),
pulp root width at cemento-
enamel junction (A),
pulp-root width at midroot
level (C) and
pulp-root width at midpoint
between level C and A
(B)

75. METHOD BY KVAAL ET AL
• Mean value of all ratios excluding T
(M),mean value of width ratio B and C (W)
and mean value of length ratio P and R (L)
were substituted in the given formula.

76. CORONAL PULP CAVITY INDEX
Panoramic radiography was used to
measure:
• The length(mm)of the tooth crown (CL,
coronal length) and
• the length (mm) of the coronal pulp cavity
(CPCH, coronal pulp cavity height or
length)

77. CORONAL PULP CAVITY INDEX
Coronal length (CL) and coronal pulp
cavity height or length (CPCH) for premolar
and molar teeth

78. CORONAL PULP CAVITY INDEX
• The tooth-coronal index(TCI) was
computed for each tooth and regressed on
the real age of the sample.

79. THIRD MOLAR DEVELOPMENT BY
HARRIS AND NORTJE
They gave five stages of third molar root
development with corresponding mean
ages and mean length:
• Stage 1 (cleft rapidly enlarging—one-third
root formed, 15.8+1.4 years, 5.3+2.1 mm);
• Stage 2 (half root formed, 17.2+1.2 years,
8.6+1.5 mm);
• Stage 3 (two-third root formed, 17.8+1.2
years, 12.9+1.2 mm);
• Stage 4 (diverging root canal walls, 18.5+
1.1 years, 15.4+1.9 mm);
• Stage 5 (converging root canal walls,
19.2+1.2 years, 16.1+2.1 mm)

80. Five stages of lower third molar root
development (Harris and Nortje` method)

81. VAN HEERDEN METHOD
• Van Heerden assessed the development
of the mesial root of the third molar to
determine the age.

82. AGE CHANGES IN THE MANDIBLE
At birth Two halves of mandible are united
by fibrous symphysis menti.
Deciduous sockets partly
separated.
Mandibular canal at lower border.
Mental foramen below first
deciduous molar.
Angle of mandible obtuse.
1st to 3rd postnatal
years
Two halves join.
Body elongates.
Mental foramen alters and occupies
adult direction and position.

83. AGE CHANGES IN THE MANDIBLE
Adults Alveolar and sub alveolar parts of
body are of equal depth.
The mental foramen is mid way
between upper and lower borders.
Mandibular canal runs parallel to
the mylohyoid line.
The angle of the mandible
measures about 110o
Old age Loss of teeth is a usual feature.
Alveolar part is resorbed.
Bone reduces in size.
Mandibular canal and mental
foramen are close to the upper
border of the body.
Angle of the mandible is about 140o

84. OSSIFICATION AROUND THE WRIST
JOINT
• The lower end of the radius appears at
around 2 years and that of the ulna around
6 years.
• Both unite with the shaft between 15 and
17 years in females and 17 and 20 years
in males.
• The order of appearance of ossification
centres in the carpal bones is as follows:
– Capitate 2–4 months
– Hamate 3–5 months
– Triquetral 1–3 years
– Lunate 3–4 years
– Scaphoid, trapezium and trapezoid 4–6 years
– Pisiform 8–10 years

85. A simple illustration to remember ages of ossification
of carpal bones

86. Pisiform, the last carpal bone to ossify has
appeared, indicating
that the age is above 12 years. The
epiphysis of the 1st metacarpal has
not united, indicating that the age is less
than 16 years.

87. OSSIFICATION OF THE STERNUM
• The union of the four sternebrae occurs
from below upwards.
– union of 3rd and 4th sternebrae at 4–10 years
– union of the 2nd and 3rd at 11–16 years
– union of the 1st and 2nd at 15–20 years
• The xiphoid process often unites with the
body after 40 years.
• The manubrium can unite with the body
after 60–70 years but often remains
separate.

88. Lateral view of the sternum of an 18-year-
old male.
Note that while the 3rd and 4th sternebrae
have united, the 2nd and 3rd, and
the 1st and 2nd sternebrae have not

90. ESTIMATION OF AGE IN OLDER
PERSONS
• An antero-posterior (Towne) view of the
skull must be used to visualize all major
sutures. This view readily shows the
sagittal, coronal and lambdoid sutures.
The same sutures can also be seen in
postero-anterior radiographs of the skull.
Both these X-rays must be advised, as
different sutures may be seen clearly in
different positions.
• The basisphenoid suture is visible in the
submento-vertex radiograph of the skull.

91. ESTIMATION OF AGE BY CRANIAL
SUTURE CLOSURE

92. ESTIMATION OF AGE IN OLDER
PERSONS
• An X-ray of the lumbar and cervical spine
often shows lipping of the vertebrae and
the appearance of osteophytes after the
age of 40 years.
• A chest X-ray may show ossification of
costal cartilages.

93. SEX DETERMINATION

94. DETERMINATION OF SEX FROM
SKULL
• In general the skull of the male is larger
than that of the female.
• In male, the orbits are more square. Nasal
apertures are higher and narrower with
sharper margins. Prominent supraorbital
ridge.
• The female skull is rounded and delicately
sculpted. The forehead is usually more
vertical, supraorbital ridges are minimal in
size & more rounded than in male.
• A skull in which presence of persistent
metopic suture is present always displays
female characteristics.

95. DETERMINATION OF SEX FROM
SKULL
• There is significant difference between
male and female skull in relation to degree
of muscular marking, size of mastoid
process, supraorbital ridge, depth of the
symphysis menti, breadth of the palate,
contour of the forehead, development of
the cheek bones.

96. DETERMINATION OF SEX FROM
ANGLE OF THE MANDIBLE
• The lateral aspect of the mandible in male
frequently shows a marked roughening or
ridged appearance due to the attachment
of the masseter muscle.
• The lower border may deviate laterally to a
marked extent in the male.
• The angle of the mandible in females is
rounded and gracile in construction and
the attachment surface for masster muscle
is much smoother.

97. RADIOLOGY IN RACE
DETERMINATION

98. • It has been suggested that the enamel of
the molar teeth may extend down between
the roots in Chinese race more commonly
than in European.
• The presence of enamel pearls on the
roots of teeth may also be visible
radiographically and this might indicate a
person of Eskimo origin.
• Pulp cavity in molars of Mongoloid race is
said to be exceptionally deep and wide.

99. USE OF
ORTHOPANTOMOGRAM IN
FORENSIC ODONTOLOGY

100. • Happonen RP et al(1991) recommended
use of orthopantomogram in identification
which enables visualization of the
structures of the jaws and related areas as
a single radiograph.

101. Skull placed on a wooden pole and positioned in
the panoramic x-ray machine

102. DIGITAL AUTOPSY

103. • When modern method of multisliced
computed tomography is used, the scan
time for a full body examination of a fatality
with a gunshot wound to the head is
approximately 60 seconds.

104. ADVANTAGES OF THE FORENSIC
APPLICATION OF MSCT
1. Rapid
2. Nondestructive documentation process
3. More precise than standard forensic
autopsy
4. Any new 2-D view can be easily
reconstructed from the native data set
5. 2-D MPR creates coronal, sagittal and
any other oblique views from the axial
data set
6. It is possible to reconstruct three-
dimensional views to visualize soft tissues
and bone.

105. LIMITATIONS OF THE FORENSIC
APPLICATION OF MSCT
• As there is no circulation clinically
established, use of intravenous contrast
agents is not available, preventing the
method from being used for questions like
the assessment of vascular flow and
detailed vascular morphology, tissue
perfusion, bleeding sites or tissue
differentiation.

106. IDENTIFICATION OF DENTAL
IMPLANTS ON RADIOGRAPHS

107. • Morphological features of dental implant
depicted on radiographs may be used to
develop a dental profile of the individual
and this can narrow the search to a
smaller number of individuals, or eliminate
certain candidates by taking into account
the dental system employed.
• The matching of two sets of radiographs is
performed with postmortem periapical
radiograph of implant against the dental
implants image of various implant system
stored in the archive.

116. REFERENCES:
1. Textbook of Dental and Maxillofacial Radiology, 2nd Ed.-
Freny R. Karjodkar
2. Panchbhai AS. Dental radiographic indicators, a key to
age estimation. DMFR. 2011; 40: 199-212.
3. Aggarwal A. Estimation of age in the living: in matters
civil and criminal. J Anat. 2009; 1-17.
4. Raitz R, Fenyo-Pereira M, Hayashi AS, Melani R.
Dento-maxillo-facial radiology as an aid to human
identification. J Forensic Odonto-stomatology. 2005; 23:
2: 55-59.
5. Nicopoulou-Karayianni K, Mitsea AG, Horner K. Dental
diagnostic radiology in the forensic sciences: two case
presentations. J Forensic Odonto-stomatology. 2007;
25: 1: 12-16.
6. Chandrashekhar T, Vennila P. Role of radiology in
forensic odontology. JIAOMR. 2011; 23(3): 229-231.