Children's teeth: what happens, and when

Canadian guidance points to a first dental visit by around the first birthday, or within six months of the first tooth appearing. It is a short appointment and mostly not about treatment: it is about the child learning that this room is unremarkable, and about you getting feeding and cleaning advice before habits set.

Wipe the gums before there are teeth, and brush from the moment the first one appears. A smear of fluoride toothpaste for under-threes, a pea-sized amount after that. Children need help or supervision with brushing until roughly seven or eight — the manual dexterity simply is not there before then.

Milk, formula and juice all contain sugars. A bottle taken to bed pools them around the upper front teeth for hours. It is the single most preventable cause of severe early childhood decay. Water only, once the teeth are being cleaned before sleep.

They hold the space for the adult teeth behind them, they are how a child chews and learns to speak, and an abscess in one is as painful as in any other tooth. Losing them early to decay causes crowding problems that outlast them.

• 6–12 months — first teeth appear, usually the lower front pair.
• Around 3 — the full set of twenty baby teeth is usually in.
• 6–7 — the first adult molars arrive at the back, behind the baby teeth. They are permanent, and they are frequently mistaken for baby teeth.
• 6–12 — baby teeth are gradually replaced.
• 12–13 — second adult molars.
• 17–25 — wisdom teeth, if they come at all. Plenty of people never get all four.

Wide variation is normal. A tooth arriving several months either side of these is not by itself a problem.

Fissure sealants are a thin coating over the grooves of the back molars, where most childhood decay starts. They are quick and involve no drilling. Ask whether they are worth it for your child.

And the one to remember: if an adult tooth is knocked out, put it back in and go straight to a dentist. If a baby tooth is knocked out, do not put it back — you can damage the adult tooth developing above it.