Teeth have important medicolegal significance for purposes such as personal identification, age estimation, and bite mark analysis. Their anatomy includes structures like enamel, dentin, cementum, and pulp. Dental characteristics like tooth size and shape, restorations, and developmental stages are unique to an individual and can be used to identify human remains. Bite marks on skin can provide evidence in criminal cases by matching dental features to a suspect's teeth. Teeth are also examined for signs of disease or substance use that may be relevant to investigations.

1. TEETH AND IT’S MEDICOLEGAL
IMPORTANCE

2. TEETH??
Hardest part of body attached to jaws. It serves to help
digest food, act as a defense mechanism, etc. teeth are
made of a crown with enamel surrounding a pulp.

3. Each tooth has three
anatomical parts:
I.Crown
II.The Neck: cervical line or
cemento-enamel junction (CEJ).
II.Root (s)
Tooth Anatomy
1- Macro-anatomy of the tooth
Enamel
Cementum

4. Tooth Anatomy
2- Micro-anatomy of the tooth
-Three calcified tissues:
Enamel Dentin
Cementum
+ One soft specialized
connective tissue:
Pulp.
Cementum
Periodontal
Ligament

5. Enamel: Covers dentin in the crown, The Most Mineralized
Tissue in the body, Transparent, and Yellowish White in color
Cementum: Covers dentin in the root, acts as a Medium For
Tooth Attachment, Dull Yellowish in color .
Dentin: Surrounds The Pulp Cavities, Underlying Enamel and
Cement, it is Softer than Enamel
Yellowish in color.
Pulp: Soft Connective Tissue present In The Pulp
Cavity, Contains blood vessels(nourishment) & nerve
Supply of the Tooth(sensation).

6. Anatomy Of The Pulp Cavity
1 - Pulp chamber
and pulp horns present in
the crown, also called
coronal pulp
2 - Root canal
radicular pulp, present in
the root, end at the apical
foramen and sometimes in
accessory canals
Note: Many roots may be
formed with more than one
canal, which may end in a
common foramen.
Consists Of Two Parts
Pulp
Horn

7. The Periodontium
Is The Investing And Supporting
Attachment System Of Teeth.
It consists of:
Two Soft Tissues Two Hard Tissues
1- Gingiva
The Oral Mucous
Membrane, Which
Covers
The Neck Of The Tooth
And Part Of
The Alveolar Bone
2- Periodontal Ligament
Strong Ligament that Attaches
The Tooth To The Alveolar Bone
1- Cementum
Covers The Anatomical
Root Of The Tooth
2- Alveolar Bone
The Bone Of The Jaw That
Surrounds The Root Of
The Tooth

8. HUMAN DENTITION

9. -Teeth Are Arranged In The Oral
Cavity In Two Arches Called The Dental
Arches One Lower And One Upper.
-The Upper Arch Is Called The Maxilla
The Teeth In This Arch Are Called Upper Or
Maxillary Teeth.
-The Lower Arch Is Called The Mandible The
Teeth In This Arch Are Called Lower Or
Mandibular Teeth.
-Each Dental Arch Has A Midline
That Divides The Arch Into Two Approximately
Equal Right And Left Segments Named As
Quadrant.
-There Are Four Quadrants In The Entire
Oral Cavity.
Dental arches and quadrant

10. Types& Grouping of Teeth

11. The Oral Cavity contains Four types
Of Teeth : in each quadrant
1-Incisors:
- There is two incisors, central incisor and
lateral incisor.
2-Canines:
-There is one canine.
3-Premolars:
-There are two premolars, First and
second premolar.
4-Molars:
-There are three molars, First molar,
second molar and third molar.
-The incisors and canines are considered
together anterior teeth since they are
closer to the midline.
- Molars and premolars are considered
posterior teeth since they are farther
from the midline.
12
3
4

12. The Dentitions
Humans have two dentitions
1-The primary dentition: (deciduous )
20 teeth. 10 maxillary and 10 mandibular.
5 teeth are present in each quadrant.
2 incisors.
1 canine.
and 2 molars.
The premolars not present in deciduous dentition.
The dental formula is:
2 1 2
I --- C ---- M ---- = 10
2 1 2
(In one side x 2 = 20 tooth

13. 2-The permanent dentition:
(secondary, adult or
succedaneous )
32 teeth, 16 maxillary and
16 mandibular.
8 teeth in each quadrant
2 incisors.
1 canine.
2 premolars.
and 3 molars.
The dental formula is :
2 1 2 3
I ---- C ---- PM --- M ---- = 16
2 1 2 3
(In one side x 2 = 32 tooth
The permanent molars are not
preceded with deciduous teeth
so they may be termed as non-succedaneous teeth.
The Dentitions

15. DENTITION Periods

16. Primary dentition
6 m - 6 y
Mixed dentition
6 y -12 y
Permanent dentition 12 y and up
Shedding: It is the
physiological loss of
the deciduous teeth
and their subsequent
replacement by
permanent teeth.
Deciduous
Permanent
Mixed

17. 1- Primary dentition
6 m - 6 y
3- Permanent dentition 12 y and up
2- Mixed dentition
6 y - 12 y
X – Ray
Showing

18. 1) Palmer Notation System:
It represents the four quadrants of the dentition as if you facing the patient.
In upper right In upper left
In lower right In lower left
The permanent teeth are numbered from 1-8 on each side from the midline.
Upper right Upper left
8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8
8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8
Lower right Lower left
The deciduous teeth are lettered from A-E on each side from the midline.
Upper right Upper left
E D C B A A B C D E
E D C B A A B C D E
Lower right Lower left
Tooth Identification System

19. This system utilizes simple brackets
to represent the 4 quadrants of the
dentition as if you facing the patient.

20. The teeth are designed by using two-digit systems:
a. The first digit of the code is located at the left side of the number and
indicates the quadrant.
In the permanent dentition. In the deciduous dentition.
U.R. 1 2 U.L. U.R. 5 6 U.L
L.R. 4 3 L. L. L.R. 8 7 L.L.
Permanent teeth
18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28
48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38
Deciduous teeth
55 54 53 52 51 61 62 63 64 65
85 84 83 82 81 71 72 73 74 75
2- The international numbering system (the two digit system)
b- The second digit is located at the right side of the number and indicates the
number of the tooth in the quadrant.
The two digits should be pronounced separately.

22. 3)The universal numbering system (American numbering
system):.
The number is always preceded by the sign # to designate that the
system is used for universal system.
Permanent teeth (1 – 32) Starting with the maxillary right third molar to the mandibular
right third molar.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
Deciduous teeth (A - T) Starting with the maxillary right second molar to the mandibular
right second molar.
A B C D E F G H I J
T S R Q P O N M L K

24. MEDICO-LEGAL IMPORTANCE

25. Medico legal importance of teeth
• Age estimation
• Personal identification
• Bite marks identification
• Identification of dental specimens at crime
scene
• Diagnosis of some chronic poisoning cases

26. AGE ESTIMATION

27. Aspartic acid racemization
L-form undergoes racemization to the D-form
Relative amount of the L and D-forms of aspartic acid in the
enamel or dentin
Tooth development stage
Radiographic method of age determination
Based on degree of tooth mineralization
Stages can be visualized on a dental panoramic tomograph
Gustafson method boyde’s method
Demirjian method stack’s method

28. Tooth eruption
Formation of alveolar cavity - 3 to 4 m of IU life
Formation of cellular tooth germ within the alveolar bone
Takes the shape of crown
Formation of enamel and dentine
Root formation begins
At birth, rudiments of all temporary teeth and of the first permanent molars may be found in
the jaws

29. Temporary teeth
TOOTH ERUPTION
• Lower central incisor 6-8months
• Upper central incisor 7-9 months
• Upper lateral incisor 9-10 months
• Lower lateral incisor 10-12months
• First molar 12-14 months
• Canine 17-18 months
• Second molar 20-30 months

30. Permanent teeth
TOOTH ERUPTION
• First molar 6-7 yrs
• Central incisor 6-8 yrs
• Lateral incisor 8-9 yrs
• 1st premolar 9-11 yrs
• 2nd premolar 10-12 yrs
• Canine 11-12 yrs
• 2nd molar 12-14 yrs
• 3rd molar 17-25 yrs

31. Temporary teeth
Tooth calcification
Lower central incisor 1.5 to 2 years
Upper central incisor 1.5 to 2 years
Upper lateral incisor 1.5 to 2 years
Lower lateral incisor 1.5 to 2 years
First molar 2 to 2.5 years
Canine 2.5 to 3 years
Second molar 3 years

32. Permanent teeth
Tooth calcification
First molar 9 years
Central incisor 10 years
Lateral incisor 11 years
1st premolar 12 years
2nd premolar 13 years
Canine 13 years
2nd molar 15 years
3rd molar 18 to 25 years

33. Gustafson’s method
• Attrition
• Paradentosis
• Secondary dentine
• Root resorption
• Transparency of root
• Cementum apposition

35. Gustafson s method
Total score = A+P+S+R+T+C
0 = no change
1 = slight change
2 = obvious change
3 = maximum change

37. 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
Various dental work

38. Dental Work That Makes Teeth Unique
Dental Crown Dental Fillings

39. Dental Work That Makes Teeth Unique
(cont)
Dental Extraction Dental Bridge

40. Lifestyles and Teeth
• Mouth of a
smoker
• Mouth of a Meth
user

41. Dentures
• There are cases where
the victim no longer
had teeth and wore
dentures.
• Records are also kept
for dentures so this
dental appliance is a
very good source.

42. Definitions of marks made by human teeth:
Tooth mark: mark left by tooth
Arch mark: mark produced by four or five adjacent
teeth & same arch
Bite mark:
:a mark made by teeth either alone or in
combination with other mouthparts

43. BITE MARKS
There are seven (7) types of bite marks which can
be classified by four (4) degrees of impression:
1. hemorrhage -- small bleeding spot
2. abrasion -- undamaging mark on skin
3. contusion -- ruptured blood vessel, bruise
4. laceration -- punctured or torn skin
5. incision -- neat puncture of skin
6. avulsion -- removal of skin
7. artifact -- bitten-off piece of body
1. clearly defined -- significant pressure
2. obviously defined -- first-degree pressure
3. quite noticeable -- violent pressure
4. lacerated -- skin violently torn from body

44. Typical presentation of bitemark injuries
•Females are most often bitten on the breasts
and legs during sexual attacks,
•whereas bites on males are commonly seen
on the arms and shoulders.
•A representative human bite is described as
an elliptical or circular injury that records
the specific characteristics of the teeth

45. Bite marks
• Investigators can
analyze bite marks for
characteristics to help
them identify victims or
suspects as well as to
exclude others.
• Marks can be left on a
victim’s skin or other
objects, such as
Styrofoam cups, gum,
or foods.

46. Bite Marks
Features to analyze:
Type of bite mark
(human or animal)
Characteristics of the
teeth (position, evidence
of dental work, wear
patterns, etc.)
Color of area to estimate
how long ago the bite
occurred (old or recent
bite)
Swab for body fluids for
DNA tests

47. Analysis of Bite Marks
• The next step is to
determine which marks
were made from which
teeth.
– The upper 4 front teeth
make rectangular marks.
– The central incisors are
wider than lateral incisors.

48. Analysis of Bite Marks
• The next step is to
determine which marks
were made from which
teeth.
– The upper and lower cuspids
tend to leave round or oval-
shaped marks.
– The lower 4 front teeth
make rectangular marks that
are all similar in width.

49. Analyzing bite marks
 Bite marks are photographed
with a scale
 Casts of impression are taken
 Impression traced onto
transparencies
 Casts of suspects teeth are
taken
 Comparison between suspect
cast and bite mark

50. Bite marks
Saliva or blood may
be left behind that
can be tested for
DNA.
Dental records
including x-rays can
also provide useful
information,
especially when
attempting to
identify a victim.

51. BITE MARKS
contusion

52. Typical presentation of bitemark injuries

53. Pink teeth
• In decomposed and skeletonized bodies
• Due to deposition of protoporphyrin
• The cause of which is not known
• Death is usually of an asphyxial nature and damp
environment is involved

54. Hutchinson’s teeth
• Permanent upper central incisors get notched
and stunted
• Seen in congenital syphilis
• Fournier’s tooth --Syphilis also produces
disturbance of the dentine-enamel junction
and dwarfing of the crown in permanent
molars

55. Coloration is due to changes in the
composition or thickness of the dental
tissues
• Brown Alkaptonuria
• Yellow green Cong hyperbilirubinemia
• Brown grey tetracycline
• Chalky white to dark brown fluorosis
• lead line plumbism