Teeth development in children

The development of deciduous teeth begins while the baby is still in the womb. At about 5 weeks’ gestation, the first buds of the deciduous teeth form in the baby’s jaws. At birth, a baby already has all their deciduous teeth (10 in the upper jaw and 10 in the lower jaw), along with some permanent teeth developing within the jaws.

Deciduous teeth are also known as baby teeth, milk teeth, first teeth, or primary teeth.

Types of teeth#

There are four main types of teeth, each shaped for a particular job:

• Incisors – the front teeth in the upper and lower jaws. Each incisor has a thin cutting edge, and the upper and lower incisors come together like a pair of scissors to cut food.
• Canines – the pointed teeth on each side of the incisors in the upper and lower jaws, used to tear food.
• Premolars – teeth with flat surfaces that crush food.
• Molars – larger than premolars and set towards the back of the mouth, with broad, flat surfaces that grind food.

How teeth erupt#

‘Eruption’ refers to a tooth breaking through the gum line. In babies, this process is called teething.

The time for each tooth to erupt differs from child to child. One child may have their first tooth come through when they are only a few months old, while another may not have a tooth erupt until they are 12 months old or more. Although the exact timing varies, the order of tooth development is more consistent.

The lower incisor teeth are usually the first to erupt, followed by the upper incisors and then the first deciduous molars. The average child has all 20 deciduous teeth by the age of 3 years.

Approximate eruption and loss of baby teeth#

Upper teeth:

• Central incisor – erupts 8–12 months, lost 6–7 years
• Lateral incisor – erupts 9–13 months, lost 7–8 years
• Canine (cuspid) – erupts 16–22 months, lost 10–12 years
• First molar – erupts 13–19 months, lost 9–11 years
• Second molar – erupts 25–33 months, lost 10–12 years

Lower teeth:

• Central incisor – erupts 6–10 months, lost 6–7 years
• Lateral incisor – erupts 10–16 months, lost 7–8 years
• Canine (cuspid) – erupts 17–23 months, lost 9–12 years
• First molar – erupts 14–18 months, lost 9–11 years
• Second molar – erupts 23–31 months, lost 10–12 years

Teething symptoms#

A baby’s immune system starts to change at around 6 months of age. Combined with the tendency to put things in their mouths, this makes babies more prone to minor illnesses around the same time that teeth are coming through. As a result, symptoms of common childhood illnesses are often mistakenly linked to teething.

Symptoms genuinely related to teething usually last around 48 hours and can include changes in sleep and eating patterns, fussiness, a mild rash, drooling, a runny nose, and loose stools. If your child has these symptoms for longer, it is important to speak to your child’s doctor to check for other causes, such as bacterial, viral, or middle-ear infections.

Sometimes you may see a blue-grey bubble on the gum where a tooth is about to appear. This is called an eruption cyst, and it usually goes away once the tooth comes through.

Managing the teething process#

During this time it is important to help keep your child comfortable. You can:

• Gently massage the gum with a clean finger or a soft, wet cloth. Pressure from a cool object can relieve teething discomfort.
• Offer a chilled (not frozen) teething ring or rusk. Do not sterilise plastic teething rings in boiling water or in the dishwasher unless the manufacturer says this is safe.
• Offer unsweetened teething rusks or sugar-free teething biscuits to infants over 6 months who have started eating solids.

Check the product information before buying teething rings, and avoid those that use a plastic softener called diisononyl phthalate.

The skin around the mouth, particularly the chin, can become irritated by drool. Gently wipe it away with a soft cloth throughout the day.

Pain-relieving medication#

Paracetamol works well for infants and can be used if your child is uncomfortable. Ibuprofen may also help, but it is not as well tolerated in infants. Always follow the dosing instructions and check with a pharmacist or doctor if you are unsure.

Treatments that are not recommended#

Some popular teething remedies are best avoided.

Amber teething necklaces. Amber is believed by some people to release a soothing oil on contact with warm skin. Although these strings or necklaces are designed to be worn around the neck, wrist, or ankle, they are sometimes chewed on instead. Safety authorities have warned that amber teething necklaces carry a risk of choking and strangulation. It is safer to use other, lower-risk ways of relieving teething discomfort.

Teething gels. Common teething gels contain 8.7–9.0% of the ingredient choline salicylate. Salicylate is related to aspirin, and aspirin is not recommended for children younger than 16 because in some children it has been linked to Reye’s syndrome – a rare but potentially fatal condition that can cause liver and brain damage. Teething gels may also contain numbing medication such as lignocaine (lidocaine) and benzocaine. These are difficult to measure accurately in gel form, which can lead to a toxic, even fatal, dose being swallowed. Research also suggests that teething gels may not actually relieve teething pain – it may be the act of massaging the gel into the gum that helps. The general advice is that the risk is not worth taking when safer options are available.

Caring for baby teeth#

Caring for deciduous teeth is as important as caring for permanent teeth. They allow children to chew food comfortably and to speak properly, and they hold space in the jaws for the future adult teeth.

A simple routine by age:

• From birth – clean the mouth and gums by wiping with a soft cloth.
• First tooth – brush twice a day with a soft toothbrush and plain water. Take your child for their first dental visit.
• From about 18 months to 2½ years – add a pea-sized amount of low-fluoride children’s toothpaste. Encourage your child to spit out the toothpaste, not swallow it, and not to rinse. Store toothpaste out of reach.
• From about 2½ years – begin flossing between any teeth that touch.
• From about 4–5 years – start teaching your child to brush their own teeth.
• From about 6 years – switch to adult toothpaste, still spitting out rather than swallowing or rinsing.
• From about 8 years – start teaching your child to floss their own teeth, then gradually allow them to brush and floss without supervision while continuing regular dental check-ups.

Tooth decay in baby teeth#

Tooth decay is preventable. The risk can be significantly reduced by good oral hygiene habits and a healthy diet.

Decayed baby teeth still need to be treated by a dental practitioner. In some cases, specialist treatment in hospital under general anaesthetic is needed. If neglected, decayed baby teeth can lead to mouth pain, dental abscesses (a swelling caused by infected teeth), and problems with the surrounding teeth. Severe decay can affect eating and sleep, which can slow a child’s growth. If a baby molar is lost too early because of severe decay, the adjacent baby teeth may drift into the gap and create spacing problems for the adult tooth when it comes through.

Losing baby teeth#

From the age of about 6 years, deciduous teeth start to become wobbly and fall out to make way for adult teeth. It is perfectly normal for a child to lose their first tooth up to 2 years earlier or later than 6 years of age. The first tooth to fall out is usually one of the front teeth in the lower jaw.

Losing teeth can be unsettling and uncomfortable for young children. Suggestions for parents include:

• Reassure your child that losing baby teeth is a natural process, and that new adult teeth will grow in their place.
• Expect gums to be a little tender and to bleed slightly, although some children feel little or no discomfort.
• Use a cold pack, or an over-the-counter anti-inflammatory or pain-relieving medication, to ease loose-tooth pain. Ask your dentist or pharmacist to recommend a suitable medication for your child.
• Make use of the Tooth Fairy. The idea of a small reward in exchange for a tooth can soften the experience of tooth loss for your child.

Permanent teeth#

Permanent teeth are also known as adult teeth or secondary teeth. They start to develop in the jaws around birth and continue developing through childhood. By about 21 years of age, the average person can have 32 permanent teeth – 16 in the upper jaw and 16 in the lower jaw. The third molars, commonly called wisdom teeth, do not always develop, or often do not erupt, so some people have only 28 permanent teeth.

At about 6 years of age, the first permanent molars erupt. These 4 molars (2 in each jaw) come through behind the child’s baby teeth. The other permanent teeth – the incisors, canines, and premolars – erupt into the spaces left by deciduous teeth that have fallen out.

As with deciduous teeth, the timing varies, but the general order and rough timeline is:

• First molars – between 6 and 7 years
• Central incisors – between 6 and 8 years
• Lateral incisors – between 7 and 8 years
• Canine teeth – between 9 and 13 years
• Premolars – between 9 and 13 years
• Second molars – between 11 and 13 years
• Third molars (wisdom teeth) – between 17 and 21 years, if at all

Mouthguards protect children’s teeth#

Mouthguards help protect teeth and prevent dental injuries, particularly when playing and training for contact sports. All children who play contact sports should wear a custom-fitted mouthguard, even at primary-school age. Custom-fitted mouthguards are comfortable, allow speech, and do not restrict breathing.

Key points#

• Deciduous teeth are also known as baby teeth, milk teeth, first teeth, or primary teeth.
• The average child has all 20 deciduous teeth by the age of 3 years.
• Symptoms of common childhood illnesses are often mistakenly linked to teething; true teething symptoms usually last around 48 hours.
• Teething can be managed without medication; if symptoms persist, see your child’s doctor.
• Caring for baby teeth is as important as caring for permanent teeth.

Where to get help#