Dental anatomy is the study of human tooth structures, it is concerned with the naming of teeth and the structures of which they are made, this information serving a practical purpose in dental treatment.
Tooth formation begins before birth, and teeth's eventual morphology ( shape ) is dictated during this time.
Teeth (singular tooth) are small, calcified, whitish structures found in the jaws (or mouths) of many vertebrates that are used to break down food.
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| Lower permanent teeth |
Numbering systems
For the dentist to identify a specific tooth, every tooth should have its own number or name. There are several different dental notation systems for associating information to a specific tooth.The systems depends on
- If the tooth is permanent or deciduous (primary or milk ) teeth .
- The side of the tooth,and if upper or lower ( the quadrant of the mouth).It is drawn as a symbol (┘└ ┐┌) ,or numbers ( for the permanent 1-4 )
- Number of the tooth starting from the mid-line of the mouth .
- They use also letters , primary teeth are indicated by a letter A to E .
- Another way is using continuous letters or numbers . The uppercase letters A through T are used for primary teeth and the numbers 1 - 32 are used for permanent teeth.
Primary teeth
Ten are found in the maxilla (upper jaw) and ten in the mandible (lower jaw), for a total of 20.
In the primary set of teeth, there are two types of incisors - centrals and laterals, and two types of molars - first and second, and a canine .
All primary teeth are normally later replaced with their permanent counterparts.
Permanent teeth
Among permanent teeth, 16 are found in the maxilla and 16 in the mandible, for a total of 32.
In the permanent set of teeth, there are two types of incisors - centrals and laterals, and three types of molars - first ,second,and third molar and a canine . There are set of premolars before the molars first and second premolars .
Anatomy of the tooth
Crown and root
The tooth is composed of upper part ( crown ),and lower part ( root ).
Crown
Simply it is the visible part of the tooth in the mouth. It is covered with enamel.
Enamel is the white outer part of the tooth. It is the hardest and most highly mineralized substance of the body. After the enamel there is the other layer which is dentin.
Dentin is softer than enamel, it decays more rapidly and is subject to severe cavities if not properly treated. The dentin is more sensitive than the enamel and more nearer to the dental pulp which is the inner most layer.
The dental pulp is the central part of the tooth that contains blood vessels and nerves that enter the tooth from a hole at the apex of the root.
Root
The root is the part of the tooth inside the jaw bones .
The only difference between the crown and root is that the root is covered with cementum not enamel .
Cementum is a specialized bone like substance covering the root of a tooth.It is softer than either dentin or enamel .
The principal role of cementum is to serve as a medium by which the periodontal ligaments can attach to the tooth for stability.
Periodontal ligaments
The periodontal ligament is a specialized connective tissue that attaches the cementum of a tooth to the alveolar bone. This tissue covers the root of the tooth within the bone.It has many important functions .
Alveolar bone
It is the bone of the jaw which forms the alveolus around teeth
Gingiva
The gingiva ("gums") is the mucosal tissue that overlays the jaws.
Thanks
MR
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