Week One
Subject: Basic Science
Class: Primary Four (Age 9)
Week of the Second Term: 1st Week
Topic: Human Body (The Mouth) – The Feeding System: The Teeth – Incisors and Canines
Subtopics:
- Types and functions of incisors and canines
- Identifying incisors and canines in the mouth
Instructional Objectives
At the end of the lesson, pupils should be able to:
- Identify incisors and canines in their mouth.
- Explain the functions of incisors and canines in the feeding process.
- Demonstrate the use of incisors and canines when chewing soft food (e.g., bread).
Entry Behaviour
Pupils should already know the general structure of the human mouth and have a basic understanding of its role in eating.
Instructional Materials
- Chart showing different types of teeth.
- Flashcards illustrating the functions of incisors and canines.
- Textbook with diagrams of the human mouth.
Reference Materials
Ijiyemi, C. (2016). Foundations of Science & Technology for Primary School Book 4. Lagos: Metropolitan Publishers.
Oyinlola, M., Rahaman, B., & Ezeume, I. (2015). Basic Science and Technology for Primary School Book 4 (BEC Edition). Lagos: Spectrum Book Limited.
Content
The Human Body: The Mouth
The mouth is part of the human body that plays a major role in feeding. The teeth help us to bite, tear, and chew food. Incisors are the sharp, flat teeth at the front of the mouth, used for cutting food. Canines are pointed teeth located next to the incisors, used for tearing food. Together, these teeth help in the process of breaking down food into smaller pieces before it is swallowed.
Types and Functions of Incisors and Canines
Incisors:
- Types:
- Central Incisors: These are the two front teeth in both the upper and lower jaw. They are typically the most visible teeth when you smile.
- Lateral Incisors: Located next to the central incisors, they are smaller in size and help in biting food.
- Functions:
- Cutting and Biting Food: Incisors are sharp, flat teeth designed to cut through food, such as fruits and vegetables, during the initial phase of eating.
- Speech: Incisors help form sounds during speech, as they play a role in controlling airflow when speaking certain letters like “s” and “t.”
- Appearance: As the most prominent teeth, they contribute to the shape and look of the face, especially the smile.
Canines:
- Types:
- Upper Canines: These are pointed teeth located next to the lateral incisors, one on each side in the upper jaw.
- Lower Canines: Similarly positioned in the lower jaw, they are slightly smaller than the upper canines but equally important in function.
- Functions:
- Tearing and Piercing Food: Canines are designed for tearing and shredding food, particularly meat, making them essential for breaking down tougher food items.
- Guiding the Bite: Canines play a crucial role in guiding the upper and lower teeth into place when the jaws close, ensuring a proper bite alignment.
- Speech and Facial Shape: Like incisors, canines also assist in speech and contribute to the overall shape and symmetry of the face. Their pointed shape helps in forming certain sounds.
Identifying Incisors and Canines in the Mouth
1. Incisors:
- Location:
Incisors are the teeth located at the very front of the mouth. There are eight incisors in total, four in the upper jaw and four in the lower jaw. In each jaw, the two central front teeth are the central incisors, and the ones immediately next to them on either side are the lateral incisors. - Shape:
Incisors have a sharp, thin, and flat edge, which makes them ideal for cutting food. When you smile, these teeth are the most visible, giving them a major role in facial aesthetics. - How to Identify Them:
To identify your incisors, look at or feel the four front teeth in your upper and lower jaws. These teeth are sharp and straight, and they are the first to come in contact with food when you bite into something like an apple.
2. Canines:
- Location:
Canines, also known as cuspids, are located next to the lateral incisors. There are four canines in total, two in the upper jaw and two in the lower jaw. These are found between the incisors and the premolars. - Shape:
Canines are pointed and slightly longer than the other teeth. Their sharp, fang-like appearance makes them easy to distinguish from the flat, cutting edges of the incisors. - How to Identify Them:
To find your canines, feel for the sharp, pointed teeth located at the “corners” of your mouth. They are the third teeth from the center in both the upper and lower jaws. When tearing food, like a piece of meat, you will notice that these teeth do most of the work.
Step 1: Introduction
Lesson Presentation (Step-by-Step Procedure)
Others removed.
