The Teeth

STRUCTURE AND PARTS OF THE TOOTH

THE TEETH

Adults have four types of teeth. Incisors have a straight, sharp edge for cutting and biting. Canines tear food with their pointy shape. Bicuspids and molars have a flat surface to grind food.

The first sets of teeth of a person are called milk or temporary teeth and they are usually twenty. The temporary teeth are replaced by permanent teeth. The permanent teeth are divided into three main parts namely:

1. The Incisors: These are front teeth in the mouth which have a cutting edge. They are   used for cutting off lumps of food and are eight in number.
2. The Canine: These teeth are at both sides of the mouth. They are four sharp pointed teeth and are used for tearing food. They are sometimes called dog teeth.
3. The Premolar: they are next to the canine. They are for tearing and grinding food. They have flat surface and are usually eight in number
4. The Molar: These are large back teeth, with flattened surfaces next to premolar. They are twelve in number used for crushing and chewing of food.

EVALUATION

1. State two functions of the teeth
2. What is the first set of teeth an individual grows called?

STRUCTURE OF THE TOOTH

1. The Crown: This is the part that shows when you open your mouth or smile.
2. The Root: this part of the tooth inside the gum
3. The Neck which is the area around the surface of the gum that separates the crown from the root.
4. The Dentine: It is the tough centre of the tooth which surrounds and protects the pulp cavity.
5. The Pulp cavity: this contains blood vessel and nerves.
6. The Enamel: this is a very hard substance which covers the crown of the tooth.

CARE OF THE TEETH

1. Clean your teeth every morning and at bed time with either a clean chewing    stick or tooth brush with paste.
2. Rinse your mouth properly after each meal especially after eating sweet foods.
3. Do not pick your teeth with sharp instruments such as pins, needles etc.
4. Avoid using your teeth as nut-crackers or opener for soft drinks and beer bottles.
5. Eat balanced diets for strong healthy teeth, e.g. milk, fruit, fish, meat and other sources of calcium.
6. Exercise the teeth by chew nuts and soft bones.

CAUSES OF TOOTH INFECTION

1. Often small pieces of food are left in the mouth after meals. When these bits of food are not removed by cleaning the mouth, bacteria produce acids. The acid first destroys the enamel and then the dentine. Pain is felt, when the nerves in the pulp cavity are attacked. This causes toothache.
2. Sugars, sweets and starchy foods bring about tooth decay if their particles are left between the teeth.
3. Putting dirty objects or fingers in the mouth can introduce germs which cause tooth decay.
4. Lack of care for the teeth, failure to clean the teeth regularly can cause tooth infection.
5. Habit of picking teeth with sharp pointed articles like pins and hard tooth-pick should not be encouraged as these can puncture the gum and make way for germs to enter.

PREVENTION OF TOOTH DECAY

1. Clean the teeth regularly and properly.
2. Keep your tooth brush or chewing stick clean.
3. Do not use another person’s tooth brush or chewing stick.
4. Visit the dentist whenever you have a tooth problem.
5. Eat more hard crunchy or crisp food to give the teeth plenty of exercise.

GENERAL EVALUATION

1. How can you prevent tooth decay?
2. Explain the causes of tooth decay.
3. Explain the term tooth decay
4. Mention the parts of the teeth
5. Explain mouth odour

WEEKEND ASSIGNMENT

1. The first set of teeth which human beings grow are called (a) Childhood (b) Milk teeth (c) Permanents teeth (d) Junior teeth.
2. Which of the following is important for healthy teeth? (a) Floride (b) Chloride (c) Protein (d) Nutrient.
3. ______ are replaced by permanent teeth (a) Permanent (b) Dentine (c) Temporary (d) Molars.
4. ______ are four sharp pointed teeth (a) Incisors (b) Molars (c) Premolars (d) Canine
5. _____ is the part that shows when you open your mouth or smile (a) Root (b) Crown (c) Neck (d) Milk teeth.

THEORY

1. Mention two types of teeth
2. List three parts of the teeth and explain them.

READING ASSIGNMENT

Read “The Structure, Functions, Parts and Care of the Teeth” from Home Economics for Junior Secondary Schools, by Elizabeth U. Anyakoha, Pages 21-24.