Short answer: Sucking is a natural, soothing reflex, so neither a dummy nor a thumb is a “bad habit” in a baby. A dummy at sleep time may lower the risk of sudden infant death; if you breastfeed, wait until feeding is well established. To protect talking and reduce ear infections, the NHS suggests offering a dummy only for sleep and aiming to stop by around 12 months. Strong sucking on a dummy or thumb beyond about two to four years can affect how teeth line up, but bites often correct if the habit stops before adult front teeth come through.
One grandparent says a dummy ruins teeth. The other says thumb-sucking is far worse. And all you want is for your baby to stop crying for a moment. Here's what the evidence and guidance say.
Why babies suck
All babies are born with the need to suck: they need the reflex to feed, and for many babies sucking is also calming. In the early months, comfort sucking is a need, not a habit you've created.
Dummies
Possible benefits
- Soothing for some babies, especially when settling to sleep.
- Safe sleep: some research suggests that using a dummy when settling your baby to sleep can help lower the risk of SIDS.
Possible downsides
- Breastfeeding: a dummy used before breastfeeding is well established can interfere with learning to latch and reduce how often your baby feeds. If you breastfeed, wait until feeding is going well — usually at least four weeks.
- Talking: it's hard to babble and practise sounds with a dummy in your mouth.
- Ear infections: the NHS suggests trying not to give a dummy after six months as one way to reduce ear infections.
- Teeth: strong, prolonged sucking can affect how teeth line up.
Using a dummy safely
- Offer it; don't force it. If your baby refuses, that's fine.
- Don't put it back in if it falls out once your baby is asleep.
- Never dip it in anything sweet, such as sugar or jam.
- Never tie it around your baby's neck or to clothes on a long cord.
- Check it regularly and replace it if it's worn or damaged.
- Before reaching for the dummy, check whether your baby needs a feed, a nappy change or a cuddle.
Thumb or fingers
Advantage: always available, never lost, and no night-time hunting for a dummy.
Disadvantage: you can't take a thumb away. Thumb-sucking can carry on longer than dummy use, and it's long-lasting, strong sucking that's most likely to affect teeth.
That's one reason some parents prefer a dummy: it's something you can phase out when you choose.
When to stop
The NHS suggests offering the dummy only when it's time for sleep, and aiming to stop using dummies completely by 12 months, to support talking. The American Academy of Pediatrics notes that strong sucking on a dummy, thumb or fingers beyond 2 to 4 years may affect the shape of the mouth or how teeth line up — but if the habit stops before the permanent front teeth come in, the bite often corrects itself.
How to phase out a dummy
- Limit it first: only for sleep. Not in the car, the shop or while playing.
- Pick a calm time, not alongside potty training, a new bed or a new sibling.
- Offer other comforts: a soft toy, a song, a cuddle routine.
- For older toddlers, make it a moment: swapping dummies for a small present, or “giving them to the new babies”.
- Stay steady after the first difficult nights. The first few nights are usually the hardest.
Helping with thumb-sucking
The AAP's first tip is to ignore it: most children stop on their own. Harsh words, teasing or punishment upset children and don't work. Instead, praise times when your child doesn't suck, offer something to hold during TV or stories, and for older children make a plan together. If thumb-sucking continues as adult teeth come through, ask your dentist for advice.
When to ask for advice
- You're worried about your child's speech or hearing.
- Your child has frequent ear infections.
- You're concerned about how their teeth are lining up — your dentist can check.
Related reading
- Safe sleep: the rules that matter most
- Late talkers and language development
- Ear infections in children
Month by month: The First Year (PDF, English) guides you through your baby's first twelve months.
Sources
- NHS — Sudden infant death syndrome (SIDS).
- NHS — Help your baby learn to talk.
- NHS — Ear infections.
- NHS Best Start in Life — Milk supply (dummies and breastfeeding).
- American Academy of Pediatrics, HealthyChildren.org — Pacifiers and thumb sucking.
Written by the Bloom Guides editorial team. Last updated: 19 October 2026. General information only — not a substitute for advice from your health visitor, GP or dentist.