Structure and Types of Human Teeth for Class 4 Science
- The human tooth is the hardest part of the human body. It can be divided into two parts—tooth crown and tooth root.
- The tooth crown remains outside, and the tooth root remains inside our gum. A typical human teeth structure is given below with a labelled image—
- Different Types of Teeth in Humans:
|Types of Teeth||Functions of teeth|
|Incisors||These are front teeth that help in biting and cutting food.|
|Canines||These teeth are placed at the corners of the mouth; they are sharp and help tear food.|
|Premolar teeth||These are present behind the canines; these teeth help grind the food.|
|Molar teeth||These are located behind the premolars; these help grind and chew food properly.|
Human Teeth Structure
Which Part of Our Tooth Has Nerve and Blood Supplies?
- The pulp of our tooth has nerve and blood supplies and is softer than other parts of the tooth.
- For the same reason, we feel pain when the pulp gets affected by infections.
What is Mastication?
- The process of chewing food is called mastication. It is the first step of the process of digestion.
- In this process, the food is crushed and ground by our teeth.
- Our teeth have cusps and grooves that help chew the food.
Explain How Dental Cavities Are Formed.
- Dental cavities are formed when food gets stuck between our teeth and is not cleaned properly.
- As a result, the leftover food in the teeth is converted into acids due to bacterial action.
- The secretion of acid leads to the formation of cavities.
What Do You Understand by the Term ‘Thecodont’?
- The term ‘thecodont’ denotes the arrangement of teeth where they are inserted in socket-like structures called gums.
- All mammals are thecodont.
Explain How a Dental Cavity Can Be Treated.
Dental cavities can be treated in the following two ways—
- If the cavity is not deep and has only affected the crown, it is cleaned and filled with some tough material.
- If the cavity spreads deep into the gums, then it is cleaned, and a tooth cap is fixed in place of it. It is called root canal treatment.
What is Odontoblast?
Odontoblast is a cell found in the pulp region of the teeth. This cell is responsible for the formation of dentine.
Types of Teeth and Their Functions
Why Are the Canines of Carnivorous Wild Animals More Developed Than Herbivorous Animals?
- Carnivorous animals feed on the flesh of other animals.
- Tigers, leopards, and lions hunt herbivorous animals like deer, rabbits, monkeys, etc.
- Depending on their food habit, the canines are more developed in carnivore animals to help tear flesh.
Write the Dental Formula of Humans and Explain It.
The dental formula of humans is—
- There are 8 incisors; 4 in the upper jaw and 4 in the lower jaw.
- There are 4 canines; 2 in the upper jaw and 2 in the lower jaw.
- There are 8 premolars; 4 in the upper jaw and 4 in the lower jaw.
- There are 12 molars; 6 in the upper jaw and 6 in the lower jaw.
What Is the Difference Between Milk Teeth and Permanent Teeth?
The differences between milk teeth and permanent teeth are—
|Milk teeth||Permanent teeth|
|i) Milk teeth have soft enamel.||i) Permanent teeth have hard enamel.|
|ii) These teeth have shorter and thinner roots with a few nerve branches.||ii) These teeth have longer and thicker roots with developed nerve branches.|
|iii) They are 20 in number.||iii) They are 32 in number.|
What is ‘Heterodont’?
The type of teeth arrangement where the teeth vary in shape and size is called heterodont.
What is Scurvy?
- Scurvy is caused due to deficiency of vitamin C.
- It affects gums and leads to swollen and bleeding gums.
- Scurvy is also characterised by bruised skin.
Why Do Some People Wear Dental Braces?
- Dental braces are used to correct misaligned or crooked teeth.
- Braces can cure bite issues and can improve smiles.
- These are made with high-quality metals.