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Chalky Teeth (MIH) in Children: Signs, Causes and Treatment

Some children's back teeth come through with soft, chalky, discoloured enamel. This is molar incisor hypomineralisation (MIH). Here is what it looks like, what is and is not known about the cause, and how dentists treat it.

Updated September 2026·By the OHA editorial team·7 min read·How we write
Key takeaways
  • Molar incisor hypomineralisation (MIH), often called "chalky teeth", means the enamel of some teeth formed with too little mineral, so it is softer than normal.
  • It usually affects the first adult back teeth (molars), which come through at around 6, and sometimes the front teeth. Baby back teeth can be affected too.
  • Affected teeth may be white, creamy, yellow or brown, can be sensitive, and decay or crumble more easily.
  • The cause is not known. Illness in early childhood, high fevers and a difficult birth have been suggested, but none is proven.
  • Treatment ranges from fluoride varnish and sealants to fillings, metal crowns and, for badly affected molars, removal at a planned age.

"Chalky teeth" is the everyday name for a problem with how tooth enamel forms. The Better Health Channel (Victoria) explains that teeth become chalky if the enamel, the hard outer surface, does not harden properly while the tooth is forming. The dental term is hypomineralisation, meaning less mineral than normal. When it affects the first adult molars, and sometimes the front teeth, it is called molar incisor hypomineralisation (MIH).

The Better Health Channel notes that chalky teeth can be confused with tooth decay, so a dentist needs to look. For other causes of pale patches, see white spots on teeth.

Which teeth are affected?

NHS hospital trusts in Leeds, Kent and London (Guy's and St Thomas') say MIH usually affects one or more of the first adult molars, and sometimes the adult front teeth (incisors). Guy's and St Thomas' and The Rotherham NHS Foundation Trust add the adult canines.

MIH is usually noticed at around 6 to 7, when these adult teeth come through (Leeds, Kent, Guy's and St Thomas'). The Better Health Channel says the baby molars, which come through at around 2, can also be affected. Kent Community Health NHS Foundation Trust says this may be a sign that the adult teeth will be affected too.

What does it look like?

Affected enamel may look white, creamy, yellow or brown, and severity can vary from tooth to tooth (Kent). The Better Health Channel describes creamy-brown or very white spots, like the colour of chalk. The Leeds leaflet says many children have no symptoms or mild ones.

Sensitivity and decay

Because the enamel is softer:

  • Sensitivity. Teeth may be painful or sensitive to hot, cold or sweet foods, and sometimes to brushing (Leeds, Kent).
  • Crumbling. In more severe cases, parts of the tooth can crumble or break away, more often on back teeth (Kent).
  • Decay. The Better Health Channel says chalky teeth have a much higher risk of tooth decay.
  • Numbing. The Rotherham trust says affected teeth can be harder to numb with local anaesthetic for dental treatment.

Guy's and St Thomas' says that without treatment, sensitive and broken-down teeth can keep breaking down, leading to pain, damage to the nerve inside the tooth, infection or an abscess.

How common is it?

Figures vary:

  • UK: leaflets from Leeds, Kent, Rotherham and Guy's and St Thomas' say around 1 in 8. A leaflet from St George's University Hospitals NHS Foundation Trust says up to 20% of UK children.
  • Australia: the Better Health Channel says about 1 in 6 children have chalky teeth.
  • Worldwide: a 2021 review of 116 studies in Scientific Reports estimated about 13.5%, and found that studies using different definitions of MIH reported different rates. Researchers at the University of Melbourne put chalky molars, including baby molars, at over 1 in 5 children worldwide.

What causes chalky teeth?

The cause is not known. The 2021 review calls it a defect of unknown cause. The NHS leaflets say it is thought to come from a disturbance while the teeth are forming, around the time of birth or in the first few years of life.

Several possible links have been suggested, but not proven:

  • severe childhood illness, including chest illness, and high fevers (Leeds, Guy's and St Thomas')
  • a traumatic birth (Leeds, Kent, Guy's and St Thomas')
  • exposure to environmental pollutants, low birth weight or antibiotics (Rotherham)

Kent says that sometimes there is no obvious cause. St George's says a traumatic birth, childhood illness and high fevers have been found to be associated with MIH, which means they occur together more often, not that they have been shown to cause it.

The University of Melbourne researchers, writing in Frontiers in Physiology, say the cause remains unclear despite 100 years of study, and that chalky molars do not appear to be mainly genetic. They have proposed a working model in which albumin, a protein found in blood, reaches the developing enamel and blocks the growth of its mineral crystals. It is a model for future research, not a settled explanation.

How is it diagnosed?

Your child's dental team will examine the teeth and may take X-rays. Guy's and St Thomas' says they will also ask about your child's medical and family history, to rule out other causes of enamel problems.

How do dentists treat it?

Treatment depends on which teeth are affected and how badly. The NHS leaflets describe similar options.

Back teeth

  • Fluoride varnish painted on the teeth to reduce sensitivity and help protect them. Guy's and St Thomas' says every 3 months; Kent says every 3 to 6 months. See fluoride explained.
  • Fissure sealants on mildly affected teeth, to protect the grooves on the biting surface. See fissure sealants.
  • Fillings, either temporary ones to stabilise the tooth or permanent white fillings. Kent says fillings usually involve local anaesthetic, especially if the tooth is sensitive and drilling is needed.
  • Preformed metal crowns: silver-coloured caps that cover the whole tooth. Kent says these usually do not need drilling or numbing, and are often used to protect a tooth until the right time to remove it.
  • Removal (extraction) of a molar that is badly broken down and unlikely to last. If done at the right time, the next adult molar can drift forward into the space, leaving little or no gap (Kent, Guy's and St Thomas'). Kent says the right time is judged from X-rays, usually between 8 and 10 years old, sometimes with advice from an orthodontist (a specialist in tooth position). Leeds says that if a lower molar is in poor condition, the matching upper molar is sometimes removed too, even if healthy, so it does not over-grow into the space. Kent says that if a tooth is removed after the ideal age, a gap may remain.

Front teeth

Front teeth rarely break down or decay (Leeds), so treatment is mainly for sensitivity and appearance:

  • fluoride varnish for sensitivity
  • microabrasion, which removes a very thin outer layer of stained enamel; Leeds and Kent say it can make the look worse if the patch is large
  • resin infiltration, where a tooth-coloured resin soaks into the white patch; suitable only in some cases
  • a thin layer of white filling over the front of the tooth
  • whitening, where UK leaflets differ: Leeds says it is not currently legal under 18, and Kent says it may be considered in special circumstances in some dental hospitals. See stained teeth.

Helping a child with sensitive teeth

The NHS leaflets suggest:

  • Help with brushing. Guy's and St Thomas' says children may avoid brushing sensitive teeth, so support them, especially on the affected teeth.
  • Use warm water. Leeds says brushing with warm rather than cold water can sometimes help with sensitivity.
  • Use fluoride toothpaste twice a day. Leeds and Kent advise toothpaste with at least 1,450 ppm fluoride. This is UK advice; toothpaste guidance differs by country, so see children's teeth and ask your dentist.
  • Ask about extra fluoride. In the UK, a fluoride mouthwash can be used from age 7 and a stronger prescription toothpaste from age 10 (Leeds, Kent, Guy's and St Thomas').
  • Keep sugar to mealtimes. Leeds says limiting sweet foods and drinks to mealtimes is especially important with MIH.
  • Keep to check-ups so problems are found early (Kent, St George's).

If your child is nervous about dental treatment, see dental anxiety.

When to see a dentist
  • Your child's new adult teeth come through with white, creamy, yellow or brown patches, or seem to crumble or chip.
  • Your child says teeth hurt with hot, cold or sweet food, or avoids brushing some teeth.
  • Your child's baby back teeth look chalky or discoloured.
Get help urgently
  • A swollen face or jaw, or signs of a dental abscess: the NHS says ask for an urgent dental appointment or call NHS 111 (or your local equivalent).
  • Call 999 (or your local emergency number) if your child finds it hard to breathe, speak or swallow, or has a lot of swelling in the mouth (NHS).

Frequently asked questions

Did I cause my child's chalky teeth?

The cause is not known. The NHS leaflets say it is thought to be a disturbance while the teeth were forming, around birth or in early childhood, and possible links such as illness or high fever are suggestions, not proven causes.

Will my child's other teeth be affected?

MIH mainly affects the first adult molars and sometimes the front teeth and canines. Kent says chalky baby molars may be a sign that the adult teeth will be affected too.

Will my child need a tooth taken out?

Many children do not. Removal is considered when a molar is badly broken down and unlikely to last, and timing it well can let the next molar move into the gap (Kent, Guy's and St Thomas').

Sources

  1. Oral conditions: young children, Better Health Channel (Victoria), accessed September 2026
  2. Molar incisor hypomineralisation in children, Guy's and St Thomas' NHS Foundation Trust, accessed September 2026
  3. Molar incisor hypomineralisation, Kent Community Health NHS Foundation Trust, accessed September 2026
  4. Molar-incisor hypomineralisation (MIH): information for patients and parents/guardians, Leeds Teaching Hospitals NHS Trust, accessed September 2026
  5. Molar Incisor Hypomineralisation (MIH), The Rotherham NHS Foundation Trust, accessed September 2026
  6. Molar Incisor Hypomineralisation (MIH) patient information leaflet, St George's University Hospitals NHS Foundation Trust, accessed September 2026
  7. The prevalence of molar-incisor hypomineralization: a systematic review and meta-analysis, Lopes LB and others, Scientific Reports, 2021, accessed September 2026
  8. A breakthrough in understanding the pathogenesis of molar hypomineralisation: the mineralisation-poisoning model, Hubbard MJ and others, Frontiers in Physiology, 2021, accessed September 2026
  9. Dental abscess, NHS, accessed September 2026

This article is general information about oral health. It is not a diagnosis or a substitute for advice from a dentist or doctor who knows your situation. If you have pain, swelling, bleeding that does not settle, or a problem that is getting worse, see a dental professional. In an emergency, contact your local emergency service.

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