Human teeth are designed for tearing, mashing, crushing and chewing food so that we can get proper nutrition to our bodies. But we're not born being able to tear into a sandwich or gnaw at a piece of steak; like every other part of our bodies, human teeth go through a growth and development process that begins in the womb, and continues well into adulthood.
Before Birth
Teeth begin growing in the womb, long before birth. Around the fifth week of gestation, the beginnings of primary teeth will develop in the jaws, according to BetterHealth.gov. Ten buds will develop on the top jaw, and 10 on the bottom for a total of 20 teeth. By the time a baby is born, the teeth are almost completely formed in the gums. The strength of the developing teeth depends on the mother's health and diet, and the amount of fluoride the baby received while in the womb, according to The Children's Hospital at Westmead.
Primary Teeth
Primary teeth are often called baby teeth or milk teeth, and they typically erupt through the gums between 6 to 10 months of age. Primary teeth always cut the gums in the same order: the front teeth first, then the teeth on either side, and finally the molars, according to HealthyTeeth.org. Children typically have all 20 primary teeth by age 3. Primary teeth are responsible for holding a place for permanent teeth and guiding them in to the correct position, and helping children develop proper speech and chewing habits, according to HealthyTeeth.org.
Secondary Teeth
Secondary teeth, also known as permanent teeth or adult teeth, begin to develop in a baby's jaws after birth. They typically arrive between 6 and 7 years old, when a child's primary teeth begin to fall out. The first secondary teeth that arrive are molars, which come in before any teeth fall out and behind the primary molars, according to BetterHealth.org. Secondary teeth then come in in the same order as primary teeth. The average person will have 32 teeth by the time they're 21 years old, which includes four incisors, two canines, four premolars and six molars.
Third Molars
Third molars are often called wisdom teeth, and typically appear between 17 and 25 years old. Humans developed third molars in the past to aid in chewing but since the advent of processed food, they're unnecessary and over time people have developed smaller jaws, according to DentalHealth.org. However, the third molars still come in for most people, regardless of whether or not there is room for them. Third molars that get stuck on the teeth in front of them and come in at an angle are considered "impacted" and require removal by a dentist. Third molars also have higher risks of decay and pain, especially if they are still partially covered by the gums, according to DentalHealth.org. Most dentists will recommended removing the third molars if there isn't room in your jaw, or if they could cause problems.
Tooth Decay
Tooth decay can happen at any age, but becomes more common the older people get and the longer they've been using their teeth. Sugar, plaque and other food particles can eat away at the enamel and cause you to develop cavities in your teeth. It can also lead to gum disease, which is an infection of the tissues and bone that support the teeth, according to KidsHealth.org. If untreated, gum disease can actually lead to loss of teeth. People need to remain vigilant with their dental care as they age so teeth are around for as long as possible.
