Understanding the Development of Your Child’s Teeth

Children’s teeth develop between pregnancy and about age 12 when the last adult teeth apart from wisdom teeth erupt. According to Kids Health, a child has 20 primary (or “baby”) teeth at birth, some of which are fully developed in their jaw and ready to erupt between 6 and 12 months of age. The development of dentistry for children as a field moves with your child through their life, until they transition to adult dental care between the ages of 16 to 18.

Before Birth

Though some of the tissue specializations start happening around six weeks of gestation, the teeth take about twice that long to develop their hard tissue. This begins to happen at around the end of the first trimester to the beginning of the second trimester of pregnancy. A fetus’s teeth are protected inside the soft tissue of the gums, in which they develop. These teeth are, as most parents are aware, unerupted when the baby is born, and don’t begin to erupt until later, but by the time the baby is five months old, the teeth are all developed and ready to come out.

Tooth Development

As the fetus develops, teeth go through stages of increasing complexity. At about 5-6 weeks gestation, the mesenchyme, the initiatory form of the tooth, becomes distinct from the surrounding epithelium. Over the intervening six to seven weeks, it begins to form more and more specialized tissues, including the first development of the enamel knot as the bud’s mesenchyme differentiates into tissues and eventually, the full hard tooth develops. The first sign of toothlike development is in the cap stage halfway along, when the dental papilla starts forming along with the first knot of enamel.

From Birth To First Eruption

Babies develop a lot from the time they come out kicking and screaming to the time their first tooth cuts through their gums, between the ages of 6 and 12 months. Until your baby has enough teeth to brush, the best way to keep their mouths clean is to dampen (not soak) a clean gauze pad or soft cloth and use it to wipe the gums, making sure not to push the finger into the mouth past the gums. This should be all the dental care an infant needs in the first six months. Once the teeth start to come in, cold teething devices will help numb the gums and make it less painful to deal with the erupting teeth.

While Teething

Once the baby has begun teething, the teeth are, as mothers are well aware, quite sharp from their newness. When the baby’s gums start to become sore and tender from teething, gentle rubbing with a small cool spoon, clean finger, or a moist gauze pad can soothe them, and a clean teether to chew on can also help. But remember that not all devices marketed as teethers are baby-safe. In a September 2017 report from the CDC, there was a case of an infant who suffered lead poisoning after chewing on a teething bracelet. The bracelet was said to be a homeopathic magnetic hematite health bracelet, but it included metal beads containing lead, which poisoned the baby. If in doubt, check with pediatric dentists for questions regarding the safety and efficacy of teething devices.

Your Child’s Primary Teeth

Primary teeth are the twenty teeth that are in a child’s head from the first eruption to the teeth falling out between ages 6 and 12. These are technically called deciduous teeth because they fall out like a deciduous tree’s leaves fall, and this happens to start around age 6-7. From age 6 months to 6 years, the primary teeth serve as a child’s only teeth, and there are twenty of them: Four each central incisors, lateral incisors, cuspids (or canines), first molars, and second molars. These twenty teeth should be seen by a dentist specializing in dentistry for children. The first time should be no later than 12 months old.

Your Child’s First Dental Visit

At your child’s first dental visit, according to Stanford Medicine Children’s Health, expect your dentist to give you information on baby bottle tooth decay, infant feeding practices, mouth cleaning, teething, pacifier habits, and finger-sucking habits. If possible, schedule dental visits for young children early in the morning so they’re alert and fresh. Dental visits involve being reclined in a chair for long periods, so a tired child might fall asleep while being seen, which is undesirable.

Preschool Dental Visits

A preschooler going on a dental visit after the onset of memory (around age 3) can be prepared to know what to expect from their tooth cleaning. Building excitement for the visit by the parent may seem paradoxical, given how much adults seem to loathe dental work. This is why, as a parent, it’s important to show enthusiasm for your dentistry – even if you don’t feel it. Your kids will unconsciously mimic your attitudes toward dentistry for children because they see you as their role model.

Before Tooth Shedding

Between the ages of 3 and 6, there is an island of stability in the development of a child’s face. The primary teeth are all grown in and while you can’t see them below, the permanent teeth are developing in the jaw. More on those in the next paragraph. Age 3-6 is a good time to start teaching kids good dental habits, particularly regular brushing and flossing. Remember that for all children, but especially neurodivergent children, flossing can be hard to begin with because an overenthusiastic flossing technique can lead to pain and bleeding gums – be sure to praise even poor attempts. Your child is trying!

Development of Permanent Teeth

A four-year-old’s jaw is quite simply full of teeth, some developed and some not. It’s easy for parents to look at this time as “free time” in the development of their children’s mouths. Other changes, after all, that are far more visible are happening in their bodies as they metamorphose from toddlers to preschoolers. However, below the surface of the gums, the permanent teeth are developing out of protective niches in the mandible and the maxilla – an x-ray of a preschooler’s head, can be delightfully horrifying, with far too many teeth crammed into such a tiny head. This is another place to model grace for your small children. Since their developing mouths can experience pain from these additional teeth, having compassion is crucial to your child’s psychological development.

Permanent Tooth Eruption

Between the ages of six and twelve, the familiar tooth wiggles set in as baby teeth, typically starting with the lateral incisors and working their way around the mouth in a pattern that feels random but is ordained by nature to a certain extent, begin to loosen and fall out. Many families have a tradition of token rewards for kids when their teeth fall out. The Tooth Fairy is a longstanding tradition for a reason – the story gives kids something to lessen the shock of having part of their mouths falling out of their heads!

Dental visits during the time of permanent tooth eruption, depending on the temperament of the child, can either be simple affairs or complicated ones, as some children love showing off their missing teeth, even to strangers. This can especially include dentists and dental hygienists – and at least with these professionals, whose specialty is teeth, they can be indulged in this behavior.

Orthodontics Correct an Overfilled Mouth

Whether you want to believe it or not, the 20 perfectly-spaced teeth of your small child will soon give way to the 32 unruly teeth of an adult – too many teeth for our evolved, smaller mouths. We will deal with the final four teeth – the third molars, commonly known as wisdom teeth – in another paragraph. The body has another job in growing an additional eight teeth versus the small child’s mouth, the premolars, and bicuspids, and the other teeth are normally somewhat larger, besides, giving the mouth an overfilled look until puberty grows out the bones.

Puberty growth can be an inexact process and result in a crooked smile. Because the mouth is filled with so many teeth as an adult, often those teeth do not grow straight and it’s not uncommon for bicuspids to grow in on top of or behind the incisors, or the premolars to grow crooked. In this case, orthodontics like traditional wire braces or modern options like aligners are used to straighten the teeth and make sure that they sit in a single line.

Wisdom Teeth – to keep or extract?

The latest-erupting teeth are the third molars, called the “wisdom teeth” because they usually do not erupt until much later than the other teeth, molars included. The third molar can be a problem for children in the mouth’s already crowded world, and cause persistent oral pain for the child whose mouth is growing more teeth than it can hold. The decision is often made to have the wisdom teeth extracted, either because they’re impacted or because they grow crooked in a part of the mouth that is particularly difficult to either adequately brush or use orthodontics to correct.

Impaction means that the teeth simply never erupted from the gums. The wisdom teeth are the teeth most likely to grow impacted by far since they can be displaced so far out of line by orthodontic correction of the other teeth that they never have the chance to grow in. In some people, one or more wisdom teeth may simply never develop and end up reabsorbed by the body. Routine dental x-rays should reveal the condition of the wisdom teeth and aid in decision-making.

Will Your Child Develop Wisdom Teeth?

Some ethnicities of people have less frequent development of wisdom teeth than the world average, while some have more. Aboriginal Tasmanians practically all have wisdom teeth. Indigenous Mexicans, by comparison, almost invariably do not. The implications for dental care are relatively minor but worth discussing. If you belong to an ethnic group that doesn’t commonly develop wisdom teeth, periodic oral x-rays are still in order not just to guide treatment of the teeth that are developed, but to make sure that your kids’ teeth are growing as they should.

Oral Surgery for Wisdom Teeth

Wisdom tooth extraction is an outpatient process. With about 5 million third molar extractions performed in the United States per year, it is by far the most common single therapeutic (as opposed to cosmetic) surgical intervention performed. Wisdom tooth extraction is normally done under local anesthesia, but sedation is possible. Besides the cosmetic aspects of wisdom tooth removal, the removal of wisdom teeth is usually a hygienic necessity. Impacted wisdom teeth can easily die in the jaw, causing severe infection and swelling. Dentists now recommend the removal of wisdom teeth as soon as they have fully developed, usually around age 17 to 21, to avoid dental problems resulting from their impingement on other teeth and potential tooth death.


From the first development of the oral facia in the fetus to the eruption or extraction of wisdom teeth, children’s mouths go through a lot of changes in the twenty-one years from birth to early adulthood. A child must go through stages including primary dentition, the shedding of the primary or baby teeth, and the growth of the permanent or adult teeth. All of these stages come with physiological and psychological changes, and kids who go through them come out in the end equipped with twenty-eight to thirty-two adult teeth that, with care, are fit to handle any food they’re given to eat.

One Last Thing: Mouthguards are Essential for Sports-Playing Kids’ Teeth!

Athletics are crucial to the psychological and social development of children. Sports teach kids to handle winning with grace and losing with dignity. They are essential for teaching important life lessons about being part of an organization and contributing to a common goal. Sports, especially contact sports, can be a risk to kids’ faces. A contact sport is any sport where contact between participants is a part of gameplay. Contact sports include some of the most popular sports, like football, baseball, basketball, ice hockey, and soccer, and also some newer or emerging sports, like quad ball and roller derby. Some noncontact sports like bicycling also carry a significant risk of injury to the face, especially mountain biking or BMX.

Modern research indicates that if your children are playing a contact sport, they should wear a mouthguard to protect their teeth from injury. Like other forms of protective sports clothing, mouthguards work by spreading impact around the mouth, reducing the chance that a serious impact could be focused on one or a small number of teeth. The safest mouthguards are custom fitted, followed by boil-and-bite mouthguards. The second type is less protective but also less expensive – the best types provide protection just behind custom fits. Ask our pediatric dentist about a mouthguard for your kids’ dental health. Give us a call today!