Human dentition refers to the arrangement and structure of teeth in the human mouth. Key features include: - Thecodont - Teeth are socketed into the jawbone - Diphodont - Humans have two sets of teeth: 20 deciduous (baby) teeth that are replaced by 32 permanent teeth - Heterodont - Teeth have different shapes suited to their functions, such as incisors for cutting, canines for tearing, and molars for grinding - Teeth are made up of three parts: crown, root, and neck - Human dental formulas describe the number and type of teeth in each jaw: deciduous is 2/2, 1/1, 2/2 and

1. PAPER- IVB

2. Dentition means-
A. Arrangement of teeth in the dental arch.
B. Types of teeth present in the dental arch.
C. Characteristics of teeth.
D. Total number of teeth present in the upper and
lower jaw.
E. Dental formula.
F. Structure of teeth.
WHAT IS HUMAN DENTITION?

3. Human teeth are characterised by the following
features-
1.THECODONT- Socketed teeth, that teeth are articulated with
their root in to the dental sockets present in the dental arch.
2. DIPHYODONT- It means two set of teeth-
a. Milk set of teeth or Deciduous teeth- Present at childhood.
b. Permanent teeth- Milk set of teeth is replaced by permanent
set of teeth; these set teeth are present beyond childhood.
3. HETERODONT- Different types of teeth having different
morphological structure and functions. For example- In the milk
set there are three types of teeth, namely incisor, canine and
molar.
In the permanent set of teeth there are four types of teeth. Eg.-
incisor, canine, premolar & molar.

4. In the following way major structural feature and function of
each type of teeth may be presented:
INCISOR(I)- Anterior in position; crown is chiseled and with more
or less straight, flat and sharp. These type of teeth have single root.
Function- cutting.
CANINE(C)- Antero lateral in position in the dental arch; crown is
quite conical in shape. Such tooth is with a single root.
Function- tearing
PRE MOLAR(PM)- Such type of teeth are located behind the canine
in the dental arch. These types of teeth are usually bicuspid and
these are absent in the milk set but present in the permanent set.
Usually single root but in rare case upper premolars have two
roots.
Function- Crushing and partly chewing.

5. MOLAR(M)- Lateral in position, crown is square like shape. There
may be three or four cusps. These types of teeth usually have two
or three roots.
Functions- Grinding and crushing

7. In general human teeth consists of three main parts-
CROWN- Projected in the oral cavity and covered
with enamel, the hardest material in the human body.
ROOT- Articulated into the socket present in the jaw.
NECK- A short, constricted part in between the
crown and root.

9. The following diagram shows the arrangement of different types
of teeth in the dental arch.

10. From the diagram dental formula in case of
Deciduous teeth is- Incisors(I)2/2 Canines(C)1/1
Molars(M)2/2
Total number of Deciduous teeth- Among deciduous
(primary) teeth, ten are found in the maxilla (upper
jaw) and ten in the mandible (lower jaw), for a total of
20.
In case of permanent teeth dental formula is-
Incisors(I)2/2 Canines(C)1/1 Pre-Molars(PM)2/2
Molars(M)3/3.
Total number of Permanent teeth-Among permanent
teeth, 16 are found in the maxilla and 16 in the
mandible, for a total of 32.

12. Dental tissues-
A. Enamel- The protective outer surface of the anatomic
crown. It is 96% mineral and is the hardest tissue in the
body.
B. Dentin- Located in both the crown and root, it makes
up the bulk of the tooth beneath the enamel and
cementum. It lines the pulp cavity.
C. Cementum- This substance covers the surface of the
anatomic root.
D. Pulp- The central, innermost portion of the tooth. It
has sensory, nutritive, and functions during the life of the
tooth.

14. Abnormality in size
Microdontia is a condition where teeth are smaller than
the usual size.
Macrodontia is where teeth are larger than the usual size.
Abnormality in shape
•Fusion is the union of two adjacent teeth during
development.
•Concrescence is the fusion of two separate teeth only in
their cementum.
•Supernumerary roots is the presence of a greater
number of roots on a tooth than expected.

15. Teeth seems to be a very important part in evolution,
specially in primate evolution- a very important subject
matter of anthropology. For many dental anthropologists,
the core of the subject is tooth morphology.
Identification of different primate species is most readily
done from tooth form in archaeological and fossil
material. Among the higher primates as a whole, males
tend to have larger teeth than females, particularly the
canine teeth. Even modern humans show this to a small
extent, and it helps to distinguish between the sexes in
archaeological and forensic remains.

16. The cusps, ridges, and furrows that decorate the
crown surface also vary within different species
of primates.
Thus teeth have great importance in
anthropological studies, dentition also helps in
personal identification and age estimation and
also in sex identification.