18th May 2020

GRADE 3 : BASIC SCIENCE : WEEK 1

WEEK/TERM: THIRD TERM/WEEK 1

DATE: 07.05.2020

CLASS: GRADE 3

SUBJECT: BASIC SCIENCE

TOPIC: THE TEETH: MEANING, STRUCTURE, TYPES  AND DISEASES.

REFERENCE: STAN Basic Science and Technology for Primary School 4.

BRIEF EXPLANATION: Humans have teeth. The main purpose of the teeth is for biting, cutting and chewing food. The teeth also make humans look good and help them speak articulately. We need to care for our teeth in order to avoid tooth decay. The first set of teeth we grow, are called milk teeth and the second set of teeth which grow after the milk teeth fall off, are called permanent teeth. Babies and young children grow up twenty milk teeth. As the children grow into adulthood, more teeth grow. 32 teeth make up the complete set of permanent teeth.

 

NOTES FOR THE PUPILS:

THE MEANING OF TEETH – Teeth are hard structures found in the upper and lower regions of the jaws and used for biting, cutting and chewing.

TYPES OF TEETH.

There are four (4) types of teeth, namely:

  1. Incisors
  2. Canine
  3. Premolar
  4. Molar

The teeth are also categorized into two, namely

  1. Temporary teeth: found in children. These are 20 in number.
  2. Permanent teeth: found in adults. These are 32 in number.

Below is the diagram of the structure of a tooth. Learn the names of the different parts:

DENTAL PROBLEMS – Listed here below are some of the problems which may be experienced in the mouth, with our teeth.

  1. Bad breath (Halitosis):- This simply means bad odour from the mouth or throat. It is detected mainly when speaking, yawning, laughing or coughing. It is caused by several factors like poor digestion, infrequent brushing of the teeth, dry mouth, cigarette smoking, and infection.
  1. Cavity:- Cavity is a hole in the tooth that is caused by decay.
  1. Gum disease:- Gum disease is also referred to as periodontal disease.

PREVENTION OF DENTAL PROBLEMS – Dental problems can be prevented by following the instructions listed below:

  1. Brush your teeth at least twice a day.
  2. Eat healthy food.
  3. Avoid taking frequent snacks and drinks that have high sugar content.
  4. See your dentist regularly.

EXERCISES/ASSIGNMENTS:

Explain the following:

a. Teeth

b. Cavity

c. Halitosis

d. Periodontal disease

2. Differentiate between temporary and permanent teeth.

3. Write down the human dental formula.