Anatomy and Development of the Mouth and Teeth

 

Children's teeth begin developing in the fetus. Good nutrition from the mother during pregnancy is important in the development of the teeth. The mother's diet should have adequate amounts of calcium, phosphorus, vitamin C, and vitamin D. Certain medications, such as tetracycline, should not be taken by the mother while she is pregnant as this can cause harm to the developing teeth of the embryo. There are four main stages of development of the tooth:

  • The first stage begins in the fetus at about 6 weeks of age. This is when the basic substance of the tooth forms.
  • Next, the hard tissue that surrounds the teeth is formed, around 3 to 4 months of gestation.
  • After the child is born, the next stage occurs when the tooth actually protrudes through the gum.
  • Finally, there is the loss of the primary "baby" teeth.

Parts of the tooth:

Each tooth has four main parts, including the following:

  • enamel - the outer layer of the tooth.
  • dentin - the inner layer and the main part of the tooth.
  • pulp - part of the inside of the tooth that contains the nerve.
  • root - the part of the tooth that secures it into the jaw.
Anatomy of a tooth, cross-section
Click Image to Enlarge 

When will my child's teeth come in?

While every child is different, most of the primary teeth (baby teeth) come in between the ages of 4 and 12 months. The following are general guidelines for the eruption of the baby teeth:

  • The first tooth to erupt is usually a middle, front tooth on the lower jaw, known as the central incisor. This is followed by the second central incisor on the lower jaw.
  • Next, the four upper incisors usually come in.
  • The above is followed by the first four molars, and the remaining bottom two lateral incisors. Lateral incisors are beside of (lateral to) the central incisors.
  • Then the cuspids, or the pointed teeth, appear.
  • Usually, after the child reaches 2 years old, the four second molars (the last of the baby teeth) appear.

The teeth on the upper jaw usually erupt one to two months after the same tooth on the lower jaw. There are a total of 20 primary teeth. Usually, about one tooth erupts per month once the teeth have started coming in. There is normally a space between all the baby teeth. This leaves room for the larger permanent teeth to erupt.

Eruption of teeth happens at different times for each child. Below, we have provided average ages of eruption and shedding:

Illustration demonstrating the age of eruption and shedding of teeth, baby teeth
Click Image to Enlarge 

When will my child's permanent teeth come in?

Your child will begin losing his/her primary teeth (baby teeth) around the age of 6. The first teeth to be lost are usually the central incisors. This is then followed by the eruption of the first permanent molars. The last baby tooth is usually lost around the age of 12, and is the cuspid or second molar. There will be a total of 32 permanent, or adult, teeth.

Illustration demonstrating the age of eruption of adult teeth
Click Image to Enlarge 
Latest Kids' Health News
HIV drugs not linked with child psychiatric problems

February 7, 2012 — CHICAGO (Reuters) - Drugs used to treat children infected with the virus that causes AIDS do not appear to increase the risk of psychiatric problems in children, U.S. researchers said on Monday.

Child abuse experts calls for US campaign

February 5, 2012 — NEW YORK (Reuters Health) - Nearly 4,600 U.S. children were hospitalized with broken bones, traumatic brain injury and other serious damage caused by physical abuse in 2006, according to a new report.

Many kids still exposed to secondhand smoke in cars

February 5, 2012 — NEW YORK (Reuters Health) - A new government study reports that while fewer kids and teens are getting exposed to secondhand smoke while riding in the car, rates of exposure are still high enough to warrant concern.

Select news items provided by Reuters Health