Molar Incisor Hypomineralisation Flashcards
Name the cells that form enamel
Ameloblasts
What is the stimulus that causes ameloblasts to start making enamel
Dentine deposition which causes ameloblasts to retreat from the ADJ
What do Amelobalsts do
They secrete matrix protein that calcify immediately
This forms enamel
Apart from matrix secretion what else do ameloblasts of
They secrete enzymes that remove the organic component and allow full mineralisation of the matrix proteins
What problems can occur with enamel deposition
- Hypoplastic enamel
2. hypomineralsition
What causes Hypoplastic enamel
Physical disruption during the laying down of the enamel matrix
What causes hypomineralsition
Can occur either int eh calcification stage or in the maturation stage
How can the classification of enamel defects be split
- Systemic
2. local
What can cause localised enamel defects
- Trauma
2. Infection
What can cause systemic enamel defects
- Genetic
2. Environmental cause
What is the only genetic condition that can lead to enamel defects
Amelogenisis imperfecta
What can environmental systemic enamel defects be split into
- Chronological defect
2. Generalised defect
Give an example of a generalised environmental enamel defect
Fluorosis
Give an example of a chronological environmental enamel defect
Molar incisial hypomineralisation
What terms can we use to describe enamel defects
- Demarcated
- Diffused
- Hypoplastic
What does demarcated mean when referring to enamel
- Distinct, clear boundaries
2. Yellow, white or brown in colour
What does diffused mean when referring to enamel
- No clear boundaries
2. Lines, patchy or confluent areas
What does hypoplastic mean in terms of enamel
Loss of enamel
Pits or grooved present
How do we describe enamel suffering from molar incisor hypomineralisation
Demarcated
How do we describe enamel suffering from fluorisis
Diffused
How do we describe enamel suffering from localised enamel defects
Hypoplastic
How do we describe enamel suffering from amelogensis imperfect
Demarcated, Diffused and hypoplastic
What is molar incisor hypomineralisation
hypomineralisation of systemic origin of one or more first permanent molars as well as any associated and affected incisors
What are other terms used to describe MIH
- Molar hypomineralisation
- Incisor hypomineralisation
- Deciduous molar hypomineralisation
What does the term hypomineralised mean
A disturbance of enamel formation resulting in a reduced mineral content
What does the term hypoplastic mean
Reduced bulk or thickness of enamel
Enamel NEVER formed
If enamel is a brownish/ yellow colour what does that indicate
It is most porous
If enamel is a whitish/ yellow colour what does that indicate
It is less porous
What problems can hypomineralsed molars cause
- Post eruptive breakdown
- Can be sensitive
- Teeth are more susceptible to caries
- Teeth decay faster
- Teeth are more difficult to restore
How common is MIH?
5-25%
How do we treat MIH
- Start with molars and think about prognosis
What do we think about when forming long term diagnosis for MIH molars
- Multi surface defects
- Brown/yellow defects
- Is there evidence of post eruptive breakdown
- Is there pain/ sensitivity
- Is the defect extending across cusps or marginal ridges
- Caries
What considerations do we need to take before extraction permanent molars
Orthodontic considerations
Describe the ideal orthodontic situation when considering the removal of a permanent molar
- Class I occlusion
- Normal/ reduced overbite
- Mild to moderate crowding
- Minimal anterior crowding
- All permanent teeth present
At what age is ti best to carry out lower permanent molar extraction
8-9
At what age is ti best to carry out upper permanent molar extraction
Timing less critical but the space is likely to close if the molar is extracted before 11/12 yrs
When extracting permanent molars we also need to what
Compensate for iver eruption
How do we compensate for overruption when extracting a lower 6
Extract the upper 6 as well as it will most lilt over erupt and cause unfavourable occlusion
How do we compensate for overruption when extracting an upper 6
We don’t need to compensate
Do we extract every MIH affected permanent molar
NO we can restore/ conserve
How can we restore/ conserve an MIH affected molar
- Tooth mousse
- Fissure sealant
- Amalgam
- GIC
- Composite
- SSC
- Onlays
Why might we use tooth mousse
If the patient has sensitivity
What conditions must be fulfilled before we place fissure sealants
- Enamel is intact ad of good hardness
- No sensitivity
- Bitewings demonstrate no caries
Do we regularly place amalgam on primary teeth
no
what options do we have to restore incisors
- Microabrasion
- Bleaching
- Resin infiltration
- Composite veneers
- Porcelain veneers