Molar-incisor hypomineralisation (MIH) Flashcards
What is MIH?
hypomineralisation of systemic origin of 1 or more of the 4 permanent first molars as well as any associated and affected incisors
What does MIH stand for?
Molar incisor hypomineralisation
What are the alternative names for MIH?
Cheesy molars, hypomineralised 6’s, idiopathic hypomineralisation, non-fluoride hypomineralisation
What is the prevalence of MIH?
3.6-25%
What are the possible differential diagnoses for MIH?
Fluorosis, amelogenesis imperfecta, turner tooth, idiopathic hpomineralisation
How can we differentiate between MIH and fluorosis?
Fluorosis is less common and effects all teeth
How can we differentiate between MIH and amelogenesis imperfecta?
Amelogenesis imperfecta often affects most teeth and runs in the family
How can we differentiate between MIH and a turner tooth?
A turner tooth affects only a localised region (often of a single tooth)
What is a turner tooth?
It is where a really decayed deciduous tooth affects the tooth germ of the permanent tooth
How does MIH present?
- affects 1+ molar and/or incisor
- demarcated patches
- white/brown/cream
- post-eruptive breakdown
- heavily restored, abnormal restorations
- calculus = sensitivity means avoid eating or brushing on the area
Which discolouration is easiest to remove?
Brown staining
What are the different causes of MIH?
Timing of insult, pyrexia, hypocalcaemia, hypoxia (child or mother)
What does critical review of the causes of MIH show?
- not really sure but likely factors include: exposure to chemicals, perinatal and neonatal problems, common childhood illnesses and medically compromised children
What is the evidence that a likely factor causing MIH is exposure to chemicals?
e.g. environmental contaminants = moderator evidence connected with breastfeeding, early cessation of breast feeding = more defects, fluoride = weak evidence (more diffuse effects)
What is the evidence the perinatal and neonatal problems cause MIH?
May increase prevalence: malnutrition, maternal health and birth problems, visible defects in e’s (coexisting factors), many confounding factors and weak evidence
What is the evidence that common childhood illnesses and medically compromised children cause MIH?
No clear evidence about cause, e.g. resp problems, otis media or other common illnesses, problems with parental recall and confounders, chronic medical problems e.g. coeliac, renal, cystic fibrosis
Which phase in development is disrupted in hypoplasia?
The SECRETORY phase (early in development)
How does hypoplasia present?
small pits and grooves, qualitative defect = gross enamel surface deficits (comes through good and breaks down quickly)
Which phase in development is disrupted in hypomineralisation?
The MATURATION phase (poor mineralisation of the matrix - later on in development)
How does hypomineralisation present?
White/brown opacities
= normal thickness but dubious quality enamel
What does hypomineralisation look like under a microscope?
Altered CaP ratio, less distinct mineral rods (harder for composites to bond to), bacterial penetration of enamel and lower hardness of enamel
What are the 2 main areas of challenge in treating MIH?
Patient factors = behaviour management, sensitivity and appearance; and restorative factors