When the hard outer layer develops differently

Hypomineralisation means the enamel—the tooth’s outer layer—contains less mineral and is weaker than normal. In molar-incisor hypomineralisation, or MIH, this affects first permanent molars and can also involve the incisors. Leeds explains that it is usually noticed as these teeth erupt around age six or seven.[1]

A patch alone does not establish the diagnosis. Examination considers the overall pattern, symptoms and other possible developmental conditions. Parents do not need to diagnose the problem themselves or assume that a tooth which looks weak cannot be kept.

A patch can become an area of breakdown after eruption

SDCEP’s guidance for children describes a range from small, clearly defined opaque areas to weakened enamel that breaks away under chewing forces. The degree of involvement can vary even between teeth in the same child.[2]

That helps explain why a newly erupted tooth can appear to break unexpectedly: weakness that developed earlier is becoming apparent in the mouth. MIH teeth may also be more susceptible to decay, so the dentist needs to distinguish the developmental defect from any decay that has developed alongside it.[2]

Brushing may be painful rather than simply unpopular

Kent’s patient information describes sensitivity or pain with brushing as well as with hot or cold foods. If a child avoids one molar while cleaning or dislikes cold water, ask why before treating it as stubbornness.[3]

Not brushing is not the solution. The dental team can plan ways to manage discomfort and protect the tooth while supporting home care. Explain which area hurts, what triggers it, and whether the patch was visible when the tooth first appeared.

One parental mistake is not a convincing explanation

The updated EAPD policy document describes MIH as involving multiple systemic and genetic factors. An association reported in research cannot identify the cause in one child from a single illness or event.[4]

Instead of dwelling on something you might have fed your child in the past, focus on how weak the enamel is now and how much discomfort it causes. Understanding that this is a developmental problem does not remove the need to prevent future decay.

Different teeth need different plans—including timing if removal is considered

Kent describes options such as fluoride varnish, fissure sealants, fillings and protective crowns, depending on the condition. Extraction may be discussed for severely affected, symptomatic teeth with a poor long-term outlook. The same treatment is not appropriate for every MIH tooth.[3]

The EAPD advises orthodontic and radiographic assessment before a planned extraction and cautions that complete spontaneous space closure is not guaranteed even with appropriate timing. Rather than assuming a weak tooth should immediately be removed—or kept at all costs because it is permanent—the plan needs to consider growth and the rest of the developing dentition.[4]

Medical reviewLast reviewed · Reviewed by: Dr. Shin Hyeongsoon, Specialist in Conservative DentistryView the doctor's profile · Korean articleThis page was translated by AI. If anything differs, the Korean original prevails.

Research and institutional sources

  1. Leeds Teaching Hospitals NHS Trust. Molar-incisor hypomineralisation (MIH). Reviewed June 4, 2025.View source ↗The meaning of hypomineralisation, typical teeth and age of recognition, and diagnostic assessment.
  2. Scottish Dental Clinical Effectiveness Programme. Caries and MIH. Prevention and Management of Dental Caries in Children.View source ↗Variation between teeth, post-eruptive enamel breakdown and caries risk.
  3. Kent Community Health NHS Foundation Trust. Molar incisor hypomineralisation. Last edited July 16, 2026.View source ↗Pain and sensitivity during brushing, and preventive, protective and treatment options.
  4. Lygidakis NA, Garot E, Somani C, Taylor GD, Rouas P, Wong FSL. Best clinical practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH): an updated European Academy of Paediatric Dentistry policy document. Eur Arch Paediatr Dent. 2022;23(1):3–21. doi:10.1007/s40368-021-00668-5. PMID:34669177.View source ↗Multifactorial aetiology, evidence levels, assessment before extraction and limits of spontaneous space closure.

Bracketed numbers in the text link to these sources. This article provides general health information; individual diagnosis and treatment plans are determined after a clinical consultation.

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