The first tooth arrives whenever it arrives, and the spread is enormous

This works through first teeth in the order the parts actually depend on each other.

A very wide range

The age at which a first tooth appears spreads across most of the first year and beyond, with both ends of that range being entirely ordinary. Occasionally a baby is born with a tooth already through, and occasionally a baby passes their first birthday without one. The order in which teeth arrive is somewhat more consistent than the timing, though even that varies between babies.

None of this predicts anything about later dental health, which is largely a matter of care and diet rather than timing. A baby whose cousin had four teeth by the same age is not behind, and there is nothing to conclude from the comparison.

What teething gets blamed for

Teething is routinely cited as the cause of disrupted sleep, fever, nappy rash, loose nappies, ear pulling, crying and loss of appetite. The evidence linking teething to most of these is considerably weaker than the confidence with which they are asserted. Studies that have looked at this have generally found associations with mild local symptoms rather than with systemic ones.

Around the four-month mark, saying so plainly matters, because the label is used to explain away symptoms that had another cause entirely. The safe position is that teething may explain mild dribbling and gum discomfort, and should not be used to explain a baby who seems unwell.

Why the misattribution happens

Teeth arrive gradually across many months, which means almost any symptom in the first two years coincides with teething in progress. That overlap makes the explanation available at all times and unfalsifiable, which is exactly what makes it unreliable.

Once feeding settles, it is also comforting, since a teething explanation implies nothing needs to be done and everyone can go back to bed. That comfort is precisely the risk, because it can delay a call about something that deserved one. A baby who is unwell should be assessed as a baby who is unwell, regardless of what their gums are doing.

When to contact someone

Fever, a baby who seems generally unwell, unusual sleepiness, changes in feeding or anything that concerns you should go to a professional. That remains true even if a tooth is visibly coming through, since the two things can perfectly well be happening at once. Nobody has ever been criticised for asking, and health services expect exactly these calls about babies.

This article gives no guidance on treating discomfort, and questions about anything applied to gums or given to a baby belong with a pharmacist or doctor.

That includes products sold as natural or homeopathic, which are not automatically safe and should be discussed with a professional.

The practical side

The uncontroversial practical measures are something safe to chew on, something cool, and dealing with the dribble before it irritates skin. Teething toys are widely used, and the ones worth having are simply the ones a baby will actually put in their mouth. Guidance on what should and should not be given to a baby to chew differs by country, and specific products have been subject to safety warnings in several places.

Checking your national guidance before buying anything marketed for teething is worth the two minutes it takes. Bibs and frequent changes of top handle the dribbling far better than anything applied to the face.

Looking after the teeth that arrive

Guidance in most countries is to begin cleaning teeth as soon as the first one appears, and the details on toothpaste differ by country. Because those details differ and are updated, take them from your national health service or dental association rather than from an article.

Establishing the habit early is generally described as easier than introducing it later, when objections are better organised. Many systems also have a recommended age for a first dental visit, which is earlier than most parents expect. Asking your health visitor what applies where you live is the simplest way to get all of this right at once.

The takeaway

Let the timing be whatever it is, start cleaning at the first tooth, and never let teething be the explanation for a baby who seems unwell.

Looking after the adults is part of looking after the baby, not a distraction from it.