Molar Incisor Hypomineralisation (MIH) is a dental condition which affects the enamel (outer layer) of permanent (adult) teeth. It makes it softer than normal. It commonly affects the first permanent molars, permanent incisors and sometimes permanent canine teeth. One, some or all of the molar teeth can be affected.
An estimated one in eight children in the UK are affected by MIH.
Normal enamel is white and hard but teeth affected by MIH have poor quality enamel (outer layer) with white, yellow or brown discolouration.
It is thought to be caused by a disturbance in tooth development at the time of birth or in the first few years of life. The exact cause of MIH is unclear, although several factors like severe childhood illness, high fevers, exposure to environmental pollutants, low birth weight or the use of antibiotics have all been suggested.
The teeth affected can be sensitive or painful, especially while tooth brushing. With the poor quality tooth structure, they can be crumbly which can lead to rapid development of dental decay. Parts of the teeth affected can chip off. The teeth can also exhibit wear. The front teeth usually do not get affected as severely. The front teeth can have white or yellow patches on them that children may find displeasing to look at, especially when they smile. The affected teeth can be more difficult to numb up with a local anaesthetic for dental treatment. At what age does this occur? It usually presents when the first adult molars and the upper front adult incisors start to erupt at the age of 6 to 7 years.
The dentist will consider how decayed or broken down the teeth are and whether they are likely to last long term.
Front teeth are sometimes treated to improve poor appearance/roughness.
Produced by the Community Dental Service, September 2021. Revision due September 2023. Version: 1.0 ©The Rotherham NHS Foundation Trust 2021. All rights reserved.