Molar incisor hypomineralisation
Last edited: 25/06/2026
What is molar incisor hypomineralisation?
Molar incisor hypomineralisation (MIH) is a developmental condition which affects the enamel (outer layer) of teeth. The enamel is softer than usual and therefore at a higher risk of developing decay, crumbling or chipping. It often affects one or more of the adult molars (back teeth) and sometimes the incisors (front teeth).
Signs and symptoms
MIH is usually noticed around the age of six to seven years when the first adult back and front teeth start to erupt in the mouth. It can sometimes affect the back baby molar teeth too, and in these cases it can be seen in the mouth from two to three years old. This may be an indicator that adult teeth may also be affected.
The teeth which are affected may be discoloured, with a white, creamy, yellow or brown appearance depending on the severity. The severity may vary between each affected tooth.
The teeth may be painful or sensitive, especially when brushing or eating hot, cold or sweet foods. In more severe cases, areas of the teeth may crumble or break away easily. This is more common with back teeth that are affected.
What causes MIH?
The exact cause is not fully understood; however, it is thought that a traumatic birth or a severe illness between birth and three years old may be linked. During this time, the affected teeth start to develop and, as a result, do not form properly, resulting in MIH. Sometimes there is no obvious identifiable cause. Around one in eight children in the UK are affected by this condition.
How is MIH treated?
- prevention only, such as fluoride varnish application by your dentist every 3 to 6 months
- fissure sealants, which are a coating placed on the chewing surface of back teeth to protect them from decay
- fillings (temporary or permanent) if there is any decay or breakdown in the tooth. This usually involves numbing using local anaesthesia, especially if the tooth is sensitive and if drilling is required
- preformed metal crowns, which are silver coloured, tooth-shaped caps made of metal and usually do not require drilling or numbing of the tooth
- tooth removal is considered in severe cases, where the chance of the tooth surviving long term without causing symptoms is low. If carried out at the correct timing, this can allow the adult tooth developing behind to drift into the removed tooth space naturally, leaving little to no gap. The correct timing for tooth removal is usually determined by a radiograph (X-rays) and is usually when the child is aged between 8 to 10 years. Before the tooth removal, we may consider consultation with an orthodontist to determine the correct time of removal and to assess orthodontic needs.
Preformed metal crowns or temporary fillings are often considered as a temporary measure for stabilisation and to prevent further breakdown before the correct time for tooth removal.
For front teeth, treatment may involve:
- fluoride varnish gel to help manage sensitivity
- resin infiltration – improves appearance by penetrating a white spot with a tooth-coloured resin. This option is only appropriate in some cases
- microabrasion, which uses an acidic polishing paste to remove the outer discoloured layer of enamel. This may take a few visits and is not always an appropriate option if the discoloured area is extensive, as it can lead to a worse appearance
- tooth whitening can be considered during adulthood to improve the aesthetic appearance but may be considered in special circumstances for those under 18 years old and is done in some dental hospitals only
- white filling to improve the aesthetic appearance.
Occasionally, combinations of more than one of the above treatments are provided.
What happens if I do not get treatment?
If the molar teeth are moderately to severely affected, having no treatment can lead to breakdown and decay of the teeth. This is likely to cause pain and sensitivity.
In advanced cases, if left untreated, this would increase the risk of the nerve of the tooth becoming affected, requiring either a nerve treatment called root canal treatment or removal of the whole tooth. If the tooth is removed after the ideal age, then a gap would remain.
What can I do to help?
Because the teeth are more likely to develop decay, it is important to focus on prevention:
- Diet: try to cut down on how much sugar is eaten and how often sugary foods and drinks are taken
- brushing: brush teeth properly twice a day using a fluoride toothpaste
- fluoride toothpaste: toothpaste with 1450 ppm fluoride helps to strengthen teeth and can even repair early decay
- fluoride mouthwash: children aged seven and over can use a fluoride mouthwash to help protect their teeth
- tooth mousse, which can be directly applied to the teeth like a cream, can also be helpful for sensitivity. This product should not be used if your child has an allergy to milk protein
- dental check-ups: regular visits to the dentist are important to monitor teeth and catch any problems early
- from age 10, a stronger fluoride toothpaste may be prescribed by your dentist
Dental visits are very important, as the dentist can apply fluoride varnish and check for any signs of decay, helping to ensure the teeth stay healthy and don’t get worse.
Useful links
Contact us
0300 123 4412
kcht.dentalhelpdesk@nhs.net
Monday to Friday, 8am to 4pm
Referral team
0330 123 9438
kcht.communitydentalservice@nhs.net
Post to Capital House, Jubilee Way, Faversham, Kent ME13 8GD
Monday to Friday, 8.30am to 5pm
This information should only be followed on the advice of a healthcare professional.
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