Forensic Odontology applied to dental practice

2. Definition
 Forensic dentistry, or forensic odontology, is the
application of dental and para dental knowledge to the
solution of legal issues in civil and in criminal matters.

3. Constituents of Forensic
Odontology
 Postmortem dental identification and disaster victim
identification
 Age estimation
 Anthropology
 Bite mark analysis

4. Areas of Practice of Forensic
Dentist
 Identification of found human remains
 Identification in mass fatalities
 Assessment of bite mark injuries
 Assessment of cases of abuse (child, spousal, elder)
 Civil cases involving malpractice
 Age estimation.

5. Means of Identification
 Teeth: Natural and synthetic (fixed and removable)
 Bone: Trabecular pattern, tori and osseous anomalies
 Presence of foreign bodies: Implants, unretrieved amalgam
particles, surgical instruments, bullets, fragments of
various origins
 Sinus configuration: Maxillary and frontal
 Skull sutures
 Soft tissue features: Rugae (rugoscopy) and lip
(cheiloscopy) prints
 Photographic comparison: Facial or dental superimposition
or approximation
 DNA.

6. Role of teeth in determination of
human identity
 Teeth resist trauma and mass disaster
 Ante mortem and post-mortem dental records
 Dentures
 Teeth as source of DNA – mtDNA – Mother / Siblings

7. Bite Marks
 Biting is a primitive type of assault. It is often used as
the weapon of last resort.
 marks left by dental casts in wax, clear overlays and
other mediums.
 bites in food or other inanimate objects used as
physical evidence to place the accused at the scene of
the crime.

8.  For bites on human skin, a potential bite injury must be
recognized early, as the clarity and shape of the mark may
change in a relatively short time in both living and dead
victims.
 Bite marks appear most often as elliptical or round
areas of contusion or abrasion, occasionally with associated
indentations. Since the skin marks are apt to change
overtime, photographs provide the most reliable means of
preserving the information.
 When there are indentations in the skin, or to
preserve the three-dimensional nature of the bitten area,
impressions should be taken to fabricate stone models.

9. Impression
 An accurate impression of the bitten surface should be
fabricated to record any irregularities produced by the
teeth, such as cuts, abrasions, etc.
 Vinyl polysiloxane, polyether or other impression
material available in the dental office that is
recommended for fixed prosthetic applications can be
used for this purpose.

11.  The distance from cuspid to cuspid
 The shape of the arch
 The evidence of a tooth out of alignment
 Teeth width and thickness, spacing between teeth
 Missing teeth
 The curves of biting edges
 Unique dentistry
 Wear patterns such as chips or grinding.

12.  Steps in data collection for bite mark analysis
1. Recognition and initial assessment.
2. Swabs of skin.
3. Photographs.
4. Measurements, drawings.
5. Impressions.
6. Preservation of skin.
7. Follow-up photographs.

13. Saliva
 Double swab technique
 1st Swab – wet with saline – Roll over the site of injury
 Air dry for more than 30 mins & store in the container
 2nd Swab – Don’t wet with saline – Roll over the site of
injury
 Air dry for more than 30 mins & store in the same
container of the first swab.

14. Mass Disaster
 The identification of large numbers
of casualties in mass disasters is complex and fraught
with hazards, both physically and emotionally.
 Preplanning, organization, coordination, and disaster
response exercises are the keys
to successful disaster management.
 The major problems facing a forensic identification
center in time of mass disaster are:

15. 1. Large numbers of human remains.
2. Fragmented, commingled, and burned remains.
3. Difficulty in determining who was involved in the
disaster.
4. Acquisition of meaningful medical and dental
records and radiographs.
5. Legal, jurisdictional, organizational and political
issues.

16. Age Estimation
 The age determination from dental examination is
possible from approximately 10 weeks intrauterine up
to old age.
 The presence of neonatal line (birth line) in both
dentine and enamel indicates live birth and a separate
existence.
 It is possible that the time period of survival can be
estimated by measuring postnatal deposition of these
hard tissues

17.  Schour & Massler's method and
Demirjian's method in children
 Gustafson's method in adults

18. Gender Identification
 Teeth size
 Jaw dimensions
 Microscopic examination of teeth in which the pulp
tissue is examined for Barr bodies (present only in
females) has been shown to be of value in burnt and
mummified remains
and is highly accurate.

19. Radiographs
 The tasks for the forensic investigator include
six steps:
1. Securing antemortem radiographs.
2. Making postmortem radiographs.
3. Comparing meaningful features (those which are stable
and
distinctive).
4. Accounting for discrepancies.
5. Assessing uniqueness.
6. Verbalizing the degree of confidence in the
identification.

20.  What to Compare?
1. Number and arrangement of teeth (missing teeth, rotated
teeth, spacing, extra teeth, impacted teeth).
2. Caries and periodontal bone loss.
3. Coronal restorations (visible in or on the crown).
4. Hidden restorations (bases under fillings, pins, root canal
fillings, posts, and implants) seen only radiographically.
5. Bony pathology.
6. Trabecular bone pattern and crestal bone topography
7. Nutrient canals.
8. Anatomic bony landmarks.
9. Maxillary sinus and nasal aperture.
10. Frontal sinus.
11. Dental anatomy

21. Cheiloscopy
 The external surface of the lip has numerous elevations and
depressions that form a characteristic pattern, referred to as lip
prints.
 Lip prints can be obtained from the crime scene from
clothing, cups, glasses, cigarettes, etc.
 Impressions are made from the lower portion of the lower lip, an area
always visible in any trace made.
 The various patterns included are vertical, intersected, branched,
reticular and undetermined.
 Various factors can alter lip printing. It has to be obtained
within 24 hours after death. Lip prints depend upon whether
the mouth is opened or closed.
 Any pathology or any postsurgical alteration may also change the
pattern.