Classification of Human Teeth

Human teeth are classified based on various characteristics such as the shape, size, and function. The three primary classifications of human teeth are:

1. Based on Shape:

There are four types of teeth classified based on their shape:

a) Incisors: These are the front teeth that are used for biting and cutting the food. There are four incisors in both the upper and lower jaws.

b) Canines: These are the sharp teeth located next to the incisors. They are used for tearing and ripping the food. There are two canines in both the upper and lower jaws.

c) Premolars: These teeth are located between the canines and molars. They have flattened surfaces and are used for grinding and crushing the food.

d) Molars: These are the largest teeth located at the back of the mouth. They have broad surfaces and are used for grinding and crushing the food.

2. Based on Number of Teeth:

a) Diphyodont: Humans have two sets of teeth - primary (deciduous) teeth and permanent teeth. This type of dentition is called diphyodont.

b) Heterodont: Humans have different types of teeth with different shapes and functions. This type of dentition is called heterodont.

3. Based on Structure and Position of Teeth:

a) Thecodont: The teeth are embedded in sockets in the jawbone, and their roots are fused to the bone. This type of attachment is called thecodont.

b) Acrodont: The teeth are attached to the surface of the jawbone, but their roots are not fused to the bone. This type of attachment is called acrodont.

c) Pleurodont: The teeth are attached to the inner side of the jawbone, but their roots are not fused to the bone. This type of attachment is called pleurodont.

d) Hyperdontia: The presence of extra teeth in the mouth is called hyperdontia.

Based on the above classifications, human teeth can be classified as Thecodont, Diphyodont, and Heterodont. Therefore, option B is the correct answer.