Although the exact timing differs, everyone develops teeth in a similar way. There’s usually a specific pattern to tooth eruption, and certain elements of each tooth. It’s interesting to not only know how to take care of your teeth, but also how you got them in the first place.

Here are some facts about your teeth:

• People have two sets of teeth. Primary (or baby) teeth develop first, followed by permanent (or adult) teeth later.
• Teeth usually erupt like a mirror; for example, the top molar on your right side should appear at about the same time as the left one.
• Teeth begin to form long before they can be seen or felt. Even though a baby’s first tooth appears at about six months old, it began developing during the second trimester of pregnancy.
• A tooth’s crown develops first, but its roots keep growing after the tooth comes through.
• By age 3, the 20 primary teeth have usually grown in and remain in place until about 6 years old. They then start to fall out to allow permanent teeth to erupt.
• Between 6 and 12 years of age, permanent teeth develop. Most adults have 32 permanent teeth.

There are two main parts of each tooth: the crown is the visible part, and the root is below the gums. The root holds the tooth in place. Your teeth have four kinds of tissue, each performing a unique role. These include:

• Enamel – the covering on the outside of the tooth’s crown. It is very hard, and protects the tooth from decay.
• Dentin – the layer under the enamel. Even though it looks like bone, dentin is not as hard as enamel. It is at more risk for decay if the enamel wears away.
• Cementum – the tissue covering the tooth’s root and helping to anchor it to the bone. It is soft and light yellow, but is usually covered by the gums. Taking good care of your gums is important so that the cementum is not exposed to plaque and bacteria.
• Pulp – the tissue located at the tooth’s center. The pulp contains blood vessels and nerves, which allows delivery of nutrients and signals to your teeth.