When a child suddenly starts sleeping badly, teeth are the first explanation that comes to mind. They are also the most common wrong one. Let's go through what is known from measurements, what you can do at home, how long this usually lasts, and when what you need is not advice from an article but a doctor.
The largest objective study on this subject is 849 children aged 3–18 months, four weeks of continuous video somnography at home (Kahn 2025). "Teething" nights and ordinary nights were compared using two independent methods of analysis. Neither showed any significant differences: not in total sleep time, not in night wakings, not in the number of times a parent came in. And on those same nights more than half of the parents reported that their child was sleeping worse because of the teeth.
The discrepancy is not new: back in a prospective observation of 125 children, sleep disturbance showed no significant association with teething, while restless wakefulness did (Macknin 2000).
A meta-analysis of 16 studies covering 3506 children from birth to three years (Massignan 2016) gives a consistent picture: gum irritation in about 87 % of children on teething days, irritability in about 68 %. Heavy drooling, wanting to chew on everything and a reduced appetite for solid food are also common companions.
That work has no separate figure for sleep disturbance. The symptom everyone names first turned out to be the one the measurements cannot see. So the correct formulation is this: teething discomfort is real, while "teething insomnia" as a separate phenomenon is not confirmed.
The "teeth" explanation has a property that makes it impossible to disprove in everyday life: from about six months to past the age of two, teeth are coming through almost continuously, and for any bad night a suitable tooth can always be found — yesterday's, today's or tomorrow's. An explanation that always fits explains nothing in particular.
The second reason is gentler: a parent's rating of their child's sleep is weakly related to objective measurements and noticeably more strongly related to the state of the parent. After a hard week a night feels worse than the records show it was. And the familiar mechanism — "at night the gum hurts more because the child is lying down" — sounds plausible but has not been confirmed by testing, so we will not repeat it.
Teething has no timetable: both the order of the teeth and the timing vary a great deal between children, and "falling behind" somebody else's schedule means nothing in itself. Usually the unsettledness lasts a few days around a particular tooth and goes away with it.
The practical benchmark is not the calendar but the duration. If bad nights drag on for weeks, the "teeth" explanation stops working: over that span the tooth has either come through or it is not the point. Then it is worth looking more widely — at the schedule, at how your child is feeling, at new falling-asleep habits.
| What people do | What is known about it |
|---|---|
| A cool teether from the fridge | The usual way to comfort: cold dulls the sensation in the gum. Nobody has measured any effect on sleep as such |
| A gentle gum massage with a clean finger | The same: it helps here and now, it does not "fix" the night's sleep |
| Cool food and drink suitable for the age | Reasonable if your child already eats solid food. Not about sleep, about comfort |
| Something hard from the freezer | Not worth it: a hard frozen surface can injure the gum |
| Teething necklaces worn round the neck | No. This is an object round the neck of a sleeping child — that cannot be called safe whatever the material |
| Rubbing the gums with "folk" preparations | No. Anything that goes into a child's mouth for pain relief is a question for the paediatrician |
| Dropping the daytime nap "so they sleep better at night" | No. Overtiredness makes the night worse — our piece on overtiredness |
On pain relief separately: whether it is needed and which kind is for a doctor to decide. We name no medicines, no doses and no regimens: they cannot be chosen from an article on the internet, and an app about sleep is not what solves that problem.
The main mistake is trying to hold to yesterday's minutes on a hard day. On days like these the rhythm drifts in both directions: your child either asks to sleep earlier than usual or, on the contrary, cannot fall asleep for a long time. That is to be expected, and there is no need to force the day to fit the norm.
The app has a marker for this: put the 🦷 "teething" chip in the note on any sleep record — it flags the whole day at once. From there the app does four things:
What is worth keeping is the frame of the evening: the familiar sequence of steps before sleep, darkness, quiet, the familiar cot. These are the props that help precisely when everything else has shifted. More on the length of windows — wake windows by age; on the setting — sleep environment.
The real risk of the teething period is not the sleepless days but what is left after them. For several nights in a row a child falls asleep only in your arms, at the breast or in the parents' bed, "just so everyone gets some sleep" — the tooth passes, but the way of falling asleep stays, and the bad nights carry on for a different reason now.
If the wakings have not stopped even after the tooth has come through, it is no longer the tooth — the other causes are covered in the article baby wakes frequently at night.
The discomfort is real: gum irritation and fussiness are confirmed by a meta-analysis of 16 studies covering 3506 children (Massignan 2016). But measurements do not find any "teething" worsening of sleep: in 849 children over four weeks of video somnography, two independent methods showed no differences between "teething" nights and ordinary ones, even though more than half of the parents reported them (Kahn 2025). A bad night while a tooth is coming through does happen — but the tooth is not the main explanation for it.
Teething has no timetable: the order of the teeth and the timing vary a great deal between children. Usually the unsettledness lasts a few days around a particular tooth and passes along with it. If bad nights drag on for weeks, the "teeth" explanation stops working — the cause is worth looking for in the schedule, in how your child is feeling, or together with a doctor.
That question is for a paediatrician to answer. We deliberately name no medicines, no doses and no regimens: Baby Sleep Planner is an app about sleep schedules, not a medical service. What is left at home are the non-medicinal ways of comforting: a cool teether from the fridge, a gum massage with a clean finger, the familiar evening routine and an adult close by.
The 🦷 marker in the note on any sleep record flags the whole day. The app widens the tolerance on wake windows in both directions, stops comparing the day's total against the reference, and leaves the day out of learning, so that an atypical day does not shift the picture of your child's rhythm. The easing carries over to the first window of the next morning too. The price: the more often the marker is set, the fewer days are left for the app to learn your child's rhythm from.
Baby Sleep Planner works out wake windows and bedtime from your child's age and sleep history, and does not count a day flagged "teething" as a failure.
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