Where Do Teeth Come From?
Teeth are formed from specialized cells which produce the three parts of the tooth—root, neck, and crown. The outer coating of the crown is made of hard enamel. This covers the dentine which forms most of the bony framework of the teeth. Channels in the dentine contain blood vessels and nerves which make up the inner-most part of the tooth, the dental pulp. Most of the higher animals, including man, are born without teeth. They develop two sets, called the milk teeth and the permanent teeth.
A human mouth contains 32 teeth. Their function is to cut, tear, and grind food, and they are specialized for this. In each jaw there are four incisors (for biting), two canines (for holding or tearing), four bicuspids (chewing teeth with a cutting edge), and six molars (for grinding). “Wisdom” teeth, the largest of all, are situated at the back of the jaw, and may not arrive until we are grown up.
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 these can cause discoloration 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 six weeks of age. This is when the basic substance of the tooth forms.
- Next, the hard tissue that surrounds the teeth is formed, around three to four 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.
When do child’s teeth come in?
While every child is different, the primary teeth begin to come in between the ages of six and 12 months. Most of the primary teeth (baby teeth) will have erupted by 33 months. Girls tend to have their teeth come in before boys. 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 (lateral to) the central incisors. Next, the four first molars come in.
- Then the cuspids, or the pointed teeth, appear.
- Usually, after the child reaches two 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.
The eruption sequence can vary quite a bit from child to child. So, don’t become overly concerned if your child’s teeth do not follow the pattern above. However, if teeth fail to come in a year after the expected time, it would be advisable to check with your child’s dentist to make sure they are developing properly.
When do 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.