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प्रश्न
Write down the explanation.
Explain the structure of tooth.
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उत्तर
Structure of tooth:
Tooth Anatomy
- A tooth consists of the portion that projects above the gum called crown and the root that is made up of two or three projections which are embedded in gum.
- A short neck connects the crown with the root.
- The crown is covered by the hardest substance of the body called enamel, which is made up of calcium phosphate and calcium carbonate.
- Basic shape of tooth is derived from dentin which is a calcified connective tissue.
- The dentin encloses the pulp cavity. It is filled with connective tissue pulp. It contains blood vessels and nerves.
- Pulp cavity has extension in the root of the tooth called root canal.
- The dentin of the root of tooth is covered by cementum, which is a bone like substance that attaches the root to the surrounding socket in the gum.
- We have four different types of teeth hence, we are heterodont. Types of teeth are incisors (I), canines (C), premolars (PM) and molars (M). Each half of each jaw has two incisors, one canine, two premolars and three molars.
- Thus, the dental formula of adult human can be represented as.
`I2/2, C1/1, PM2/2, M3/3 = (2, 1, 2, 3)/(2, 1, 2, 3)`
i.e. 8 × 2 = 16 teeth in each jaw = 32 teeths
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