Paeds: Molar Incisor Hypomineralisation

Question 1

What is Molar Incisor Hyperplasia?

Answer 1

Hypomineralisation of between 1 to 4 permanent incisors and/or FIRST molars.

Question 2

What are the characteristics of MIH?

Answer 2

Areas are clearly demarcated (botches on teeth)

Asymmetrical

Demarcated areas of the teeth appear yellow, chalky or brown.

Question 3

What causes MIH?

Answer 3

Developmental condition:
Disturbance in the later stages of amelogenesis (enamel formation) resulting in reduced mineral content.

Tooth shape is fully formed

Question 4

What can MIH be confused with?

Answer 4

Hypoplastic teeth

Question 5

What are hypo plastic teeth? How can these be confused with MIH?

Answer 5

Hypoplastic teeth:
Teeth which have reduced bulk/thickness of enamel.

MIH and hypoplastic teeth can get confused as in MIH, since the enamel is defective, it is prone to tooth substance loss. This gives the illusion that the tooth is hypoplastic - reduced bulk/thickness.

Question 6

What are the two ways a tooth can be hypoplastic?

Answer 6

True - Enamel is never formed

Acquired - Post eruptive loss

Question 7

What drug causes enamel defects in a developing foetus?

Answer 7

Tetracycline

Question 8

Since MIH is a developmental condition; in a clinical situation what three time periods should you ask the mother about?

Answer 8

Prenatal
Natal
Postnatal

Question 9

Why are questions asked from before and after birth?

Answer 9

The enamel matrix of the 1st permanent molar isn’t fully formed until a year after birth.

Question 10

What problems could occur before birth (3rd trimester) that could lead to MIH?

Answer 10

Gestational Diabetes

Question 11

What problems could occur during birth that could lead to MIH?

Answer 11

Anoxia at birth
Traumatic birth
Premature birth

Question 12

What problems could occur after birth that could lead to MIH?

Answer 12

Poor socioeconomic status

Disturbances in nutrition within the first 6 months (?)

Fever and medications associated with childhood illnesses
i.e. Rubella, chickenpox and measles.

Question 13

What causes an increase in sensitivity in a patient with MIC?

Answer 13

Increased neural tissue in the pulp of MIH patients

Question 14

Apart from neural tissue, what is there also an increased amount of in the pulp of a patient with MIH?

Answer 14

Immune cells

Question 15

What are the clinical problems of MIH?

Answer 15

Loss of tooth substance:
Enamel breaks off
Teeth more susceptible to wear
Teeth more susceptible to secondary caries - carious defective permanent teeth and an immaculate primary dentition.

Sensitivity - could lead to patient neglecting oral hygiene

Reduced appearance - could lead to psychological problems.

Question 16

What are the treatment options for MIH?

Answer 16

Composite restorations - may have problems with bonding since the enamel is defective.

GIC restorations - used as a temporary measure before tooth is extracted.
Releases fluoride and enhances strength and reduces sensitivity.

Copings

Stainless steel crowns

Extraction - used in moderately/severely affected teeth.
Suitability determined by dental age (via radiograph)

Question 17

In extraction of MIH FIRST molars, what is an indication that the 6 can be removed?

Answer 17

If the root bifurcation of the lower 7 is fully formed.

Question 18

In extraction of MIH FIRST molars, if one of the 6’s is removed what must happen to the opposing 6?

Answer 18

It must also be extracted to prevent over eruption

Question 19

What are the treatment options for Incisors affected by MIH?

Answer 19

Acid pumice microabrasion - full permanent dentition

External bleaching - full permanent dentition

Porcelain veneers - carried out as an adult due to the gum levels changing throughout childhood.

Composite veneers

Localised composite placement - suitable for younger patients