Types of Teeth. Eruption.

Each type of tooth is named for ease of identification. Incisors are the front teeth located in upper and lower jaws. Each incisor has a thin cutting edge. The upper and lower incisors come together like a pair of scissors to cut the food. Canines are the pointy teeth located on both sides of the incisors in the upper and lower jaws. They are used to tear food. Premolars have flat surfaces to crush food. Molar are larger than premolars. These teeth have broad, flat surfaces that grind food.

The deciduous teeth are the first set and are also known as milk or primary teeth. There are twenty of them, ten in each jaw, five on each side.

The term eruption refers to the tooth breaking through the gum line. In babied, tooth eruption is also called teething. The timing of tooth eruption differs from one child to another. For example, one child may cut their first tooth when only a few months old, while another may not teethe until they are 12 months old or more. While the timing may vary, the order of tooth eruption is generally the same. The two front teeth (central incisors) in the lower jaw are usually the first to erupt. This occurs somewhat between the ages of 6 to 10 months. The two front central incisors in the upper jaw erupt between ages of 8 and 12 months. The lateral incisors, which are the teeth on each side of the central incisors, erupt in both the upper and lower jaws between the ages of 10 to 16 months. The lower set tends to erupt before the upper. The first set of upper and lower molars erupt between the ages of 13 an 19 months. The second set of upper and lower molars erupts between the age of 25 and 33 months. Generally the average child has their full set of 20 primary teeth by the age of three.

Between the ages of about six and seven years, the primary teeth start to shed. The central and lateral incisors in the upper and lower jaws are usually the first to go. At about the same age the first permanent teeth erupt. These four molars (two in the upper jaw and two in the lower jaw) emerge behind the child’s existing primary teeth. Other permanent teeth, such as incisors and canines, erupt into the gaps gum left by shed primary teeth. The timing of eruption differs both for deciduous and permanent teeth. Like primary teeth for when the permanent teeth come through differs from one child to the next. Generally, the order of eruption and rough timeline for each type of permanent tooth include:

• First molars – between 6 and 7 ears old;

• Central incisors - between 6 and 8 ears old;

• Lateral incisors - between 7 and 8 ears old;

• Canine teeth - between 9 and 13 ears old;

• Premolars - between 9 and 13 ears old;

• Second molars - between 11 and 13 ears old;

• Third molars (wisdom teeth) - between ages of 17 and 21, if at all.