A. UNDERSTANDING THE DEFINITION OF TOOTH
Tooth is the organ of the digestive system located in
the oral cavity. Tooth functioning as mechanical digestion tools because it
serves to cut, rip, and chew food before the food gets into the next digestive
organ. Teeth have dense and hard structure to perform its functions properly.
 |
| TOOTH |
B. PARTS TEETH
Teeth are composed of three main parts,:
1. Dental
Crown (Peak)
Dental crown is a part that is visible from outside.
This layer looks white because it is coated by a structure called the enamel.
Each type of tooth has a different shape of crown.
2. Dental Neck
(Colum)
Neck or colum is the part that is built into the
gums. This section is a barrier between the crown and the root.
3. Tooth Root
Tooth root is the part that is embedded in the jaw
(see picture) so it is not visible from the outside. Humans have some types of
teeth, every tooth can have a number of different roots, some have two roots and
some other have three roots.
 |
| TOOTH STRUCTURE |
C. THE STRUCTURE OF TOOTH
These structure is layers that forms teeth :
1. Enamel
As we have explained before, the enamel is a layer that
coat the tooth crown. The enamel had harsh nature because it is formed by
calcium. At the top part the enamel layer is the hardest part, the bottom part
will be thin so this part is not too hard. Actually, the color of the enamel is
not fully white, but grayish. The function of this layer is to protect the
teeth bone from the outside.
2. Dental cementum
The root of the tooth in the jaw lined by this cementum.
This layer also serves to protect the roots of the teeth, but the structure is
not as thick and hard as enamel. Under normal circumstances this layer is not
visible from the outside because it is covered by the jaw and gums, but some
diseases can cause visible cementum.
3. Dental Bone
This layer is located after the enamel on the crown
and after the cement layer on the root of the tooth. Dental bone is the widest
part of the tooth, its structure covering the entire length of the tooth, from
crown to root. It is named “Dental Bone” because its structure is similar to
the bone but harder because it has more calcium content. Bone also serves as a
protection, second after enamel and tooth cementum. Colors of this section are
usually yellowish.
4. Dental
Cavities (pulp)
The pulp is the soft tissue that forms on the inside
of the tooth cavity. This cavity contains blood vessels and nerve vessels. The
pulp serves as a conduit for dental nutrition because they have no blood
vessels, and to identify foreign objects, pressure, temperature and pain
because they have nerve vessels.
D. TYPES OF THE TEETH
1. Based on
the shape and function, human teeth divided into four kinds :
a. Incisors
Incisors are the teeth that serve to cut off food.
Incisor crown-shaped “upright” with the tip of his teeth shaped like a shovel.
Incisors located on the front of the tongue and have only one root. Adult human
has 4 incisors, 2 in the lower jaw, and 2 in the upper jaw.
b. Canine
Canine teeth are teeth that serve to tear and rip the
food. Canines is sharp. Canines located after the incisors. Adult human have 4
pieces canines, 2 situated in the lower jaw and the other two located in the
upper jaw.
c. Premolar
Premolars front teeth used to grind and chew food.
Premolar tooth-shaped upright somewhat wider and lower than the two types before.
Premolar tooth had a few bumps in the crown. Front molars have two pieces of
root. In adult humans there are 8 pieces of the premolar teeth 4 the lower jaw and
4 in the upper jaw.
d. Molar
Molars serve to crush, pulverize, crush and grind
food. Molar teeth shaped like premolar teeth but have a few bumps on the crown.
Most molars have three roots, but there are also some which only has two roots.
Adult human has 12 pieces molars teeth, ie 6 pieces in the upper jaw and the
other six in the lower jaw.
 |
| TYPES OF TOOTH |
2. Types of
Dental by Age teeth were divided into two, namely:
a. Deciduous teeth (Temporary Teeth/Milk
Teeth)
Deciduous teeth
are teeth that start growing in humans at about the age of 6 months. Teeth are
generally growing incisors first is located at the center of the jaw. As humans
age, one by one of these deciduous teeth are replaced by permanent teeth.
Generally, teeth start date at children aged 4-6 years. There are 20 pieces Deciduous teeth, 8 pieces
incisors, four canines and eight premolars.
b. Permanent
teeth
Permanent teeth is teeth that replace the milk teeth
and will be the teeth for a lifetime. Permanent teeth will not erupt, unless
there is an abnormality. Overall number of permanent teeth is 32 pieces, : eight
incisors, four canines, eight premolars and 12 molars.
E. STRUCTURE AROUND THE TEETH
- Periodontal ligament, the connective tissue structure that is attached to the roots of the teeth and is attached to the bone. The periodontal ligament will continue as the gingival tissue (gums) and connected with blood vessels in the bone.
- Oral mucosa, is oral cavity that is coated by stratified squamous epithelium cells. Oral mucosal main function is to protect tissue or other organs in the oral cavity.
- Gingiva (gums), an oral mucosa covering the maxillary bone and mandibula in the oral cavity. Gingival tissue itself is actually transparent in color, the red color is formed because there are many blood vessels in that section. The function is to protect the gums and tissues surrounding the tooth root.
- Nerves and blood vessels, around the teeth also are nerves and blood vessels. Neural tube serves to receive and provide a stimulus, whereas blood vessels serves to provide the intake of nutrients needed by the surrounding structures.
