molar incisor hypomineralisation Flashcards
(35 cards)
What is the definition of MIH?
Hypomineralisation of systemic origin, presenting as demarcated, qualitative defects of enamel of 1 to 4 1st permanent molars, frequently associated with incisors.
Systemic disruption at the time of calcification of those teeth can affect any teeth forming at that time.
What are the key aetiological factors associated with MIH? 3
- Disruption of amelogenesis in the early maturation stage
- Genetic and epigenetic predisposition
- Systemic factors (peri-natal and postnatal issues)
Maternal illness has no strong evidence linking it to MIH.
MIH has genetic and epigenetic predisposition. what genes have defects?
Defects in ENAM, AMELX, MMP20 genes
other than genetic/epigenetic predisposition what else needs to be present to develop MIH?
environmental factor
aetiology of MIH
systemic factors
name some perinatal problems (during birth)
Hypoxia, premature, low birth weight, prolonged/complicated birth, caesarean section
aetiology of MIH
systemic factors
name some postnatal factors (after birth)? 3
Common childhood illnesses e.g. chickenpox
Less common childhood illnesses e.g.
measles, pneumonia
Antibiotics - unknown whether cause is antibiotics or the illness they are treating e.g. ear infection
What is the prevalence of MIH worldwide?
13-14% worldwide
Which teeth are primarily affected by MIH?
- First permanent molars (6s)
- Permanent incisors (1/2s)
- May also affect 7s and 3s
Describe the clinical features of MIH 6.
- Well demarcated opacities with a clear border (white to cream to brown)
- Post-eruptive tooth breakdown (e.g., cusp fracture)
- Rapidly progressing caries in low risk child
- Sensitivity in affected molars and poor oral hygiene
- Difficulties in achieving local anesthesia
- extracted 6s
what is the mild severity classifications of MIH according to EAPD?
- Mild: no post eruptive breakdown
what is the moderate severity classification of MIH?
Teeth without post eruptive breakdown but have extensive brown patches especially young children
what is the severe severity classification of MIH according to EAPD?
post eruptive breakdown, caries, spontaneous hypersensitivity affecting function (eating, brushing)
what is the severity of incisors with MIH based on?
psycho-social impact as less likely to have sensitivity or post eruptive breakdown
What are the differential diagnoses for MIH? 4
- Caries
- Amelogenesis imperfecta
- Chronological hypoplasia
- Fluorosis
how is amelogenesis imperfect distinguished from MIH clinically?
tends to affect all teeth in the mouth
how is chronological hypoplasia distinguished from MIH clinically?
hypoplastic - different shaped teeth
how is fluorosis distinguished from MIH clinically
difficult to distinguish, less well defined opacities and history of excessive fluoride exposure
What management strategies are recommended for mild MIH in molars? 3
- manage sensitivity and caries prevention
- Resin-based fissure sealants ASAP
- Ensure correct fluoride dose
what 2 things can be used to manage sensitivity in MIH
- CPP-ACP for sensitivity
- Tooth mouse applied overnight
What management strategies are recommended for severe MIH in molars?
- Composite for smaller defects
- Indirect restorations for larger defects (gold onlay preferred)
- Hall crown to temporize the tooth
- GIC as short-term solution
- consider extraction of poor prognosis 6s
remember Restorations are more likely to fail due to bond strength, extent of restoration and difficulty treating child pts
What factors should be considered when deciding the time to extract 6s affected by MIH? 3
- what will be done with the space
*compensating extractions - infection and pain
what can be done with the space following 6s extraction? 2
Spontaneous space closure through mesial drift of 7s
Utilise space for orthodontic purposes
if infection and pain is present when should 6s be extracted?
ASAP
