Kids' Teeth by Age: A Care Guide From First Tooth to Teens

Children's mouths change a lot between the first gummy smile and the teenage years. What they need from you changes too: from wiping gums, to doing all the brushing, to supervising, to gently reminding. This age-by-age guide summarises the milestones and habits that matter most, so you know what to focus on now and what is coming next. Every child develops at their own pace, so treat the ages as rough guides rather than deadlines.

Babies (0 to 12 months)

Before teeth appear, you can wipe your baby's gums with a clean, damp cloth after feeds. This gets them used to having their mouth cleaned. The first teeth, usually the lower front teeth, often appear somewhere around six months, though anywhere from a few months to after the first birthday can be normal.

Once the first tooth shows, start brushing twice a day with a soft, small-headed toothbrush and a smear of fluoride toothpaste about the size of a grain of rice. Book a first dental visit by the first birthday. Avoid putting your baby to bed with a bottle of milk, formula or juice, because liquids pooling around teeth overnight raise the risk of early childhood decay.

Toddlers (1 to 3 years)

Most of the 20 baby teeth arrive during these years, with the back molars coming in last. Toddlers want to do everything themselves, including brushing, but they do not yet have the coordination to clean well. Let them have a turn, then you finish the job. A common trick is to stand or sit behind your child, cradling their head, so you can see into the mouth easily.

This is a good age to move from bottles toward open cups, to keep juice to a minimum (many pediatric groups recommend water and milk as the main drinks), and to avoid constant snacking, which keeps teeth bathed in sugars and starches throughout the day.

Preschoolers (3 to 6 years)

Switch to a pea-sized amount of fluoride toothpaste, and teach your child to spit it out rather than swallow it. Rinsing with lots of water afterwards is not necessary, since leaving a little fluoride on the teeth helps protect them. Keep brushing for them or checking their work; many children need help until they can write their name neatly or tie their shoes, often around six to eight.

When baby teeth touch each other, start cleaning between them with floss or floss picks, because cavities can form in those tight contacts. Your dentist may apply fluoride varnish at checkups.

School age (6 to 12 years)

Around age six, two big changes begin. The first permanent molars come in behind the baby teeth, often without any baby tooth falling out first, so parents sometimes do not notice them. And the baby front teeth start to loosen and fall out, usually beginning with the lower incisors.

Those new molars have deep grooves that trap food and bacteria. Ask your dentist about sealants, a thin protective coating painted into the grooves of back teeth. Sealants are quick to apply, do not require numbing or drilling in most cases, and are widely recommended for children's permanent molars. The second permanent molars usually arrive around age 12, and they can be sealed too.

Loose baby teeth can generally be left to fall out on their own or be wiggled gently by the child. If an adult tooth comes in behind a baby tooth that has not fallen out (sometimes called "shark teeth"), mention it at the next checkup; often the baby tooth loosens on its own, but the dentist may suggest removing it.

If your child plays contact sports, skateboards or does martial arts, a mouthguard helps protect teeth from injury. Store-bought "boil and bite" guards are an option, and dentists can make custom-fitted guards.

Orthodontic organisations suggest an orthodontic check by around age seven. This does not mean braces at seven; it simply allows early detection of bite problems where timing matters.

Teens (12 to 18 years)

Teenagers usually brush on their own, but busy schedules, sports drinks, energy drinks and late-night snacks can undo good habits. Braces and aligners make cleaning harder and more important; orthodontic patients may benefit from special brushes or water flossers. Wisdom teeth develop during the teen years and are often monitored on panoramic X-rays; not everyone needs them removed.

Teens should also know that smoking and vaping are linked with gum problems and other oral health issues, and that tongue and lip piercings can chip teeth and damage gums.

Habits that help at every age

• Brush twice a day with fluoride toothpaste in the right amount for age.
• Clean between teeth once they touch.
• Keep sweet drinks and snacks to mealtimes rather than all day.
• Offer water between meals, ideally fluoridated tap water if your area has it.
• Keep regular dental visits and ask about fluoride varnish and sealants.
• Model the habits yourself; children copy what they see.