Molar Incisor Hypomineralisation and other Dental Defects

Question 1

What is the clinical appearance of Dentinogenesis Imperfecta & Dentine Dysplasia?

Answer 1

Affects either the primary or both dentitions.
Amber,brown/blue or opalescent brown in colour
Enamel wear

Question 2

Define molar incisor hypomineralisation

Answer 2

Hypomineralisation of systemic origin, presenting as demarcated, qualitative defects of enamel of first permanent molars frequently associated with affected incisors

Question 3

Comment on the difference in lesion location in MIH vs Caries

Answer 3

MIH
Lesions occlusal, buccal and/or palatal

Caries
Lesions in fissures or mesially/distally

Question 4

MIH can increase the risk of other dental anomolies what are they?

Answer 4

• Increased risk of hypodontia (most commonly lower second premolars)
• Ectopic first permanent molars (erupt more mesially)
• Primary molar infraocclusion (teeth not rose to occlusion)
• Macrodont and microdont teeth

Question 5

What is the radiographic appearance of Dentinogenesis Imperfecta & Dentine Dysplasia?

Answer 5

Bulbous crowns
Small or obliterated pulp chambers
Roots are often narrow with small or obliterated root canals

Question 6

Comment on the predicatability of space closure for upper and lower molar extractions

Answer 6

Upper molars: predictable space closure
Lower molars: careful consideration

Question 7

Comment on the link between primary teeth and MIH

Answer 7

MIH doesnt affect the primary teeth therefore parents are always shocked when their children have MIH in permanent teeth due to their appearance

Sometimes can affect primary 2nd molars

Question 8

Comment on the appearance of opacities for MIH teeth

Answer 8

Colours can be the following:
White, Cream, Yellow, Brown

Lesions can be diffuse or well demarcated

1: Well demarcated 2: Diffuse

Question 9

At what stage in a childs life are systemic factors meant to be causative or contributing factors to MIH?

Answer 9

Last gestational trimester and first three years of life

Question 10

Comment on the enamel of hypomineralised AI teeth

AKA Hypocalcified Type III

Answer 10

The enamel is soft and may be lost soon after eruption leaving the crown composed only of dentin

Question 11

What do the number of affected teeth suggest about the systemic disturbance for MIH?

Answer 11

The number of affected teeth was associated with the time when the potential systemic disturbance occurred
(prenatal (more teeth), perinatal, postnatal)

Question 12

What is chronological hypoplasia?

Answer 12

Reduced quantity of enamel leading to pits and staining

Question 13

MIH lesions are localised and assymetrical what does this suggest about its origin?

Answer 13

Suggests a systemic origin

Question 14

When is a good time to extract lower molars affected by MIH?

Answer 14

Chronological Age 8-10 years
Upper lateral incisors erupted
2nd premolars not yet erupted

Question 15

What are the associated features of amelogenesis imperfecta?

Answer 15

Taurodontism
Delayed eruption
Anterior Open Bite
Pre-eruptive resorption
Periodontal disease

Enlargement of pulp chambers with more apical furcation

Question 16

According to the Royal College of Surgeons guidelines 2014 when would you extract a first permanent molar affected by MIH?

Answer 16

In cases where prognosis is poor, extraction is an option
(Due to lesion asymmetry, balancing and compensating extractions may be indicated)

Question 17

Comment on the prevalance of MIH in molar teeth compared to incisors

Answer 17

Risk of incisor defects increase the more molars are affected

Question 18

What are the treatment options for MIH posterior teeth?

Answer 18

Restorations - GIC or Composite
Preformed Metal Crowns
Indirect onlays - Non-precious metal, gold or tooth-coloured

Question 19

In which teeth is post-eruptive breakdown most common in MIH patients?

Answer 19

Molar teeth

Question 20

What is the prevalence of MIH in the UK for 12 year olds?

Answer 20

16% of 12 year olds

Question 21

What are the suggested possible causes for MIH?

Answer 21

Respiratory tract infections
Use of antibiotics
Perinatal complications
Dioxins
Oxygen starvation
Low birth weight
Calcium and phosphate metabolic disorders
Frequent childhood diseases

Question 22

What is dental fluorosis?

Answer 22

Hypomineralisation of enamel resulting in white opaque appearance caused by excessive fluoride intake

Question 23

How do you treat chronological hypoplasia?

Answer 23

Fill in the pits with composite

Polish and use microabrasion for staining

Question 24

When extracting a first permanent molar due to MIH do you need a compensating extarction? (upper or lower)

Answer 24

Extract at 8-10 before second permanent molar erupts;

Upper FPM: Do not compensate
Lower FPM: Compensate

Question 25

What is this an example of?

Answer 25

Chronological hypoplasia

Question 26

What is the most common cause of chronological hypoplasia?

Answer 26

Vitamin D deficiency

Question 27

What teeth does amelogenesis imperfecta effect?

Answer 27

All teeth including primary teeth

Question 28

What is hypoplastic AI?

Type I

Answer 28

The enamel thickness varies from thin and smooth to normal, with grooves, lines and/or pits

Teeth are thin and rough

Question 29

What are the treatment options for MIH anterior teeth?

Answer 29

Bleaching
Microabrasion
Etch bleach seal
Infiltration
Composite restorations/veneers
Porcelain veneers

Question 30

What are some clinical problems you may face in patients with MIH?

Answer 30

• Post-eruptive enamel breakdown → dentine exposure → pulp involvement
• Tooth sensitivity, which might lead to poor oral hygiene
• Local anaesthesia problems related to chronic pulp inflammation
• Behavioural management issues
• Aesthetics
• Tooth loss
• Multiple Appointments

Question 31

What stages of amelogensis are proposed to be affected for MIH?

Answer 31

Early maturation stage or Late secretory phase

Question 32

What clinical problems can post-eruptive breakdown lead to?

Answer 32

Post-eruptive enamel breakdown → dentine exposure → pulp involvement