The cementum, dentin, and pulp are formed from connective tissue. Its many strong fibers are embedded in the cementum and also the wall of the tooth socket. The periodontium not only helps hold the tooth in place but also acts to cushion it against the pressure caused by biting and chewing. There are 20 deciduous teeth, called also baby teeth or milk teeth, which are eventually replaced by 32 permanent teeth, evenly divided between upper and lower jaw.
Teeth have different shapes because they have different functions.
The incisors, in the front of the mouth, are shaped like a cone with a sharp flattened end, and cut the food. There are eight deciduous and permanent incisors, four upper and four lower. There are eight permanent premolars. There are 12 permanent molars in all, three on each side of both the upper and lower jaw. The hindmost molar in each of these groups, and the last one to emerge, is often called a wisdom tooth.