Download The New Aspects of Forensic Science and Important Role of Dentistry

Sci. & Cult. 76 (3–4) 135-137 (2010)
Forensic Odontology: The New Aspects
of Forensic Science and Important Role
of Dentistry
ABSTRACT : Forensic Odontology is a new branch of
forensic science associated with maxillofacial pathology
which deals with identification of a subject during
traumatic tissue injury, postmortem or lack of finger
print, bite mark analysis and resolving of legal matters.
So dental surgeon has an important role in the collection
and preservation of data and to assist the legal authority
in the identification of victims and suspects.
F
orensic dentistry, the application of dentistry to legal
structure, is a relative new aspect of forensic science.
It may be considered as an art and science of dental
medicine as applicable in resolving issue pertaining to law.
A classic in the history of forensic Odontology was the
Parkman Webster Case in 1849. Prof. Webster of the
Harvard Medical School murdered his friend Dr. Parkman
and incinerated the body. From charred jaw bones and
dental structures Parkman’s dentist identified the murdered
man. With the advent of new technology the forensic
odontology has become very important part of forensic
science.
Forensic odontology involves the management,
examination, evaluation and presentation of dental
evidence in criminal or civil proceeding and research.(2,3)
We got so many evidence from forensic odontology
like,
1. Identification of teeth as well as person.
2. Presentation of dental data as legal documents.
3. Radiographic examination and comparison and
comparison of antemortem with postmortem
subject.
4. Age determination based on dental evidence.
5. Bite mark comparison.
6. Mass disaster identification.
7. Trauma of oral tissue and underlying pathology
if any, their interpretation of oral injury and its
importance in legal matters.
8. Anthropological study and research.
VOL. 76, NOS. 3–4
9. Modeling reconstruction of face based on skeletal
evidence.
10. To identify dental malpractice and negligence.
Dental identification assumes a primary role in the
identification of remains when post mortem changes,
traumatic tissue injury or lack of finger print record. The
main advantage of dental evidence is that, like other hard
tissues, it is often preserved after death. Even the status
of a) person’s teeth changes throughout life and the
combination of decayed, missing and filled teeth is
measurable and comparable at any fixed point in time.3,4
Unfortunately dentist often maintain poor records, resulting
in poor dental identification.4 In the dental identification
the following parameters represents the features of
specificity utilized a. number of tooth b) restoration and
prosthesis c) decay (caries) d) malposition and malrotation
of tooth e) peculiar shapes of teeth f) root canal therapy
g) bone pattern seen on intra oral radiograph h) complete
denture i) bite relationship etc.1
Dental records as legal documents : The dental
record is the legal document owned by the dentist and
contains subjective and objective information about
patient. Results of the physical examination of the dentition
and supportive oral and surrounding structure must be
recorded. The results of clinical laboratory test, study
cast, photograph and radiograph should be kept for 7 to
10 years. All entries should be signed by recording
personnel.7 The antemortem dental data bank available
for comparison with the postmortem examination data rests
within the records of the attending dentist which includes
patient dental chart, dental X-ray films, and models made
from impression of the dentition. Computer generated dental
records are becoming more common for dental records.
Whether dental records are preserved in written form or
on a computer database, following the principles of record
management ensure that all information is properly
maintained and retrievable.3
Radiographic examination : Comparison of the
antemortem and postmortem radiograph is the most
accurate method of identification. Observation such as
shape of restoration, root canal treatment, root pattern,
tooth morphology, sinus and jaw bone pattern can be
identified by examination of radiographs. Original
antemortem dental radiograph are very important for
comparison. The best result obtained when the angulations
135
of films to the x-ray tube is the same as that of original
films9 Digital dental radiographic superimposition can be
used for identification, allowing comparison of the spatial
relationship of the root and the supportive structures of
the teeth in antemortem and postmortem records.10
Age determination based on dental data : The teeth
are most reliable indicators of chronological age from birth
to 14 years of age. Human dentition follows a reliable and
periodic development sequence starting from 4 months of
intra uterine life to the beginning of 3rd decade of life
when development of all permanent teeth is completed.(11)
The use of radiograph is characteristic of technique that
involve observation of morphologically distinct stages of
mineralization. Such determinations are based on root and
Gustafson’s Ranking of Structural Changes in Age
Determination:
Changes
Ranking & Details
Attrition=A
A=0 No attrition
A=1 Attrition lying within enamel
A=2 Attrition reaching dentin
A=3 Attrition reaching pulp
Periodontosis=P
P=0 No periodontosis
P=1 Periodontosis just begun
P=2 Periodontosis along first 1/3 rd
of root
P=3 Periodontosis along first 2/3 rd
of root
Secondary Dentin=S
S=0 No deposition of secondary
dentin in pulp cavity
S=1
Secondary
dentin
starts
depositing at upper part of the cavity
S=2 About half of pulp cavity being
occupied by secondary dentin
S=3 Almost whole of cavity is filled
by secondary dentin
Cementum Apposition=C C=0 Normal
C=1 A layer little greater than
normal
C=2 A thick layer
C=3 A heavy layer
Root Resorption=R
R=0 No visible resorption
R=1 Resorption
isolated spots
only
on
small
R=2 Greater loss of substance
R=3 More cementum and dentin
affected
Root Transparency=T
T=0 Transparency not present
T=1 Transparency just noticeable
T=2 Transparency over apical 1/3rd
of root
T=3Transparency over apical
of root
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2/3 rd
crown formation, closure of apical foramen, the stages of
calcification, eruption pattern.12 In elderly patient age can
be estimated by application of Gustafson’s formula (based
on aging and decaying changes in teeth).13
After about 20 years of age, following changes occur
in the teeth and based upon the changes allotted score
such as 0,1,2,3 etc. given.
Bite mark Bvidence : Comparison of bite mark
represents dentistry’s vital contribution to forensic science.
The mark pattern is compared with the dental
characteristics of the dentition of suspect. Depending upon
the situation bite mark analysis done.5,6 In cases of family
and domestic violence, physical or sexual abuse, biting
can represent a form of expression that occurs when verbal
communication fails.7 Non human biting injuries are found
on victims are usually distinguished from human bite
injuries by differences in arch alignments and specific tooth
morphology. Animal bites often cause shear rather than
impact injuries, producing open wounds.8
In general bite mark analysis is concerned with a
comparison of a life size photographic reproduction of the
bitten area with the dental model of the suspect .The first
step in the bite mark examination is the swabbing of
involved skin surface to detect the possible presence of
secretor antigens which may serve to implicate or eliminate
a particular suspect .The second step involves bite
registration from the victim or bitten object. Such
registration is done by photographic and impression
method.
Microscopic examination of the bitten tissue very
effective for pathologist to establish proximity to the time
of death .Third, registration of the suspects dentition is
accomplished by means of impression and subsequent
stone model of the tooth. In this manner examiner should
reach on a conclusion about bite mark evidence.
Mass disaster identification : In situation like
transport accident, fire or severe trauma where bodies are
often destroyed but tooth structure are heavily calcified,
so they can resist fire or huge traumas. Therefore dental
examination very important for identification. Teeth and
restoration are resistance to heat so preservation is
possible in most cases.4
The forensic odontologist has an important role as a
team member along with pathologist and other specialist
in this type of mass disaster.2
Anthropologic examination : Forensic anthropologist
and forensic odontologist may work together for
identification .The bones and teeth of craniofacial complex
SCIENCE AND CULTURE, MARCH-APRIL, 2010
remain identification for the forensic odontologist which
are distinguished one person from others and one
population from another and use to determine the race,
age and sex of a person.9
Tooth size, shape, cusp of Carabelli, enamel pearls,
and dental pulp shape are the important features for the
racial determination. American, Indian tend to be large
toothed with wide crowns and American Blacks tend to
have large crowns.
The anatomic material can be used for identification
when the skull and facial bones are used as a foundation
for the reconstruction of facial soft tissues .With the help
of different anthropologic parameter, measurements face
can be reconstructed with sculpting clay and features can
sometimes be digitized on a computer screen. Computer is
a very sophisticated tool for checking accuracy and facial
superimposition .The generated data can be stored and
reproduced for comparison.14
Conclusion : Forensic odontology is a new scientific
armamentarium in the field of forensic science. Proper
understanding of this new responsibility and implication
through proper record preservation and analysis to make
legally acceptable document and assist legal authorities in
the identification of victims and suspects.
S
R.G.Kar Medical College and Hospital
Kolkata
Received : 22 June, 2009
Revised : 31 December, 2009
1
I. M. Sopher, Forensic Dentistry, (1976) Springfield, III:
Charles C.Thomas.
2
J. M. Cameron and B. G. Sims Forensic Dentistry. (1974)
Edinburg: Churchill Livingstone.
3
B. Neville, D. Douglas, C. M. Allen and J. Bouquot Forensic
dentistry. P 763-783 (2002). In Oral & maxillofascial
pathology. 2nd ed. Philadelphia(PA) : W. B. Saudenrs Co..
4
W. U. Spitz Spitz & Fisher’s medicolegal investigation of death:
guidelines for the application of pathology of crime
investigation. Springerfield, III: Charles C.Thomas; (1993).
5
D. G. MacDonald J. Forensic Sci 14(3) : 229-33 (1974).
6
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7
Sylvie Louise Avon. J. Can. Dent. Assoc; 70(7) : 453-8, (2004)
8
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9
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10
R. E. Wood, N. J. Kirk and D. J. Sweet J. Forensic Sci; 44(5)
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11
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12
T. D. Stewart, J. Dent. Res. 42 : 264, (1963).
13
G. Gustafsons Am. Dent. Assoc., 41: 45-52 (1950).
14
R. E. Wood, B. Clark, S. E. Brooks and B. Blenkinshop, Can
Soc Forensic Sci. J. ; 29(4) : 195-203 (1996).
SHYAMAL BAR*
AND SURAJIT BOSE
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