The four types of teeth, their functions, and their development are as follows:
Incisors are a person’s eight front teeth, with four on top and four on the bottom. The two in the middle are the central incisors, while the two on either side of the central incisors are called lateral incisors. These primary teeth are later replaced by the same number of adult incisors.
Their main function is to bite food. Babies develop their incisors at around six months old. After the primary incisors fall out between ages six and eight, the permanent incisors emerge.
Canines are the sharp teeth located outside the incisors. Children and adults have four canines, two on the top and two on the bottom, to help tear their food. Canines first appear when a child is around 16 to 20 months old. The permanent lower canines come in at around 9 years old, and upper canines erupt between 11 and 12 years old.
Premolars, also called bicuspids, can chew and tear food. They are somewhat flat with ridges on top, and there are four on each side. The premolars are fully developed by about 10 to 11 years of age.
Molars also chew and grind food, yet they are stronger than premolars and they work with the tongue to help swallow food. These 12 teeth are located in the back of the mouth, and they begin to appear in children at around 12 to 15 months old.
Then the permanent molars come in, first at around six years old, and the second molars emerge in children between 11 and 13 years old.