L112. Molar Incisor Hypomineralisation

Question 1

L112: What is molar incisor hypomineralisation?

Answer 1

Hypomineralisation of systemic origin of 1-4 permanent molars, frequently associated with affected incisors

Question 2

L112: In the seventies, where was there an increased number of idiopathic cases of hypomineralised teeth?

Answer 2

Sweden

Question 3

L112: What does ‘hypomineralised’ mean?

Answer 3

Disturbance of enamel formation resulting in a reduced mineral content

Question 4

L112: What does ‘hypoplastic’ mean?

Answer 4

Reduced bulk or thickness of enamel

Question 5

L112: What does ‘true’ hypoplasia mean?

Answer 5

Enamel never formed

Question 6

L112: What does ‘acquired’ hypoplasia mean?

Answer 6

Post-eruptive loss of enamel bulk

Question 7

L112: Why is the aetiology of MIH unclear?

Answer 7

• Unclear diagnostic criteria;
• Parents cannot recall details from 8-10 years ago;
• Variation in quality of medical records;
• Study populations small.

Question 8

L112: When is the enamel matrix of crowns usually complete?

Answer 8

First year of life

Question 9

L112: When diagnosing the cause of MIH, what’re the three periods for clinical enquiry?

Answer 9

• Pre-natal;
• Natal;
• Post-natal.

Question 10

L112: In which pregnancy trimester can problems cause MIH?

Answer 10

Third

Question 11

L112: Provide examples of prenatal problems that can result in MIH in the foetus/ baby?

Answer 11

• Pre-eclampsia;

- Gestational diabetes.

Question 12

L112: Provide examples of perinatal problems that can result in MIH in the foetus/ baby?

Answer 12

• Birth trauma/ anoxia;
• Hypocalcaemia;
• Pre-term birth.

Question 13

L112: Provide examples of post natal problems that can result in MIH in the foetus/ baby?

Answer 13

• Certain childhood infections (chicken pox, measles, rubella);
• Fever and medication;
• Socioeconomic status (nutrition);
• Breast feeding (dioxins in breast milk or prolonged feeding).

Question 14

L112: Histologically, what changes can be seen with the chemical composition of hypomineralised teeth?

Answer 14

• Higher carbon content;

- Lower calcium and phosphate content.

Question 15

L112: What research suggests a presence of underlying pulpal inflammation with hypomineralised teeth?

Answer 15

• Increased neural density;
• Increased accumulation of immune cells;
• Increased vascularity.

Question 16

L112: Why are hypomineralised teeth often more sensitive?

Answer 16

• Dentine hypersensitivity (porous enamel or exposed dentine facilitates fluid flow within dentine tubules - activates Ad fibres);
• Peripheral sensitisation (underlying pulpal inflammation - c fibres);
• Central sensitisation (from cont. nociceptive input).

Question 17

L112: Alongside sensitivity, what other clinical problems are associated with MIH?

Answer 17

• Loss of tooth substance (wear/ secondary caries);

- Appearance.

Question 18

L112: What treatment options are there for treating MIH?

Answer 18

• Composite/ GIC restorations;
• Stainless steel crowns;
• Adhesively retained copings;
• Extraction (8.5-9.5 y/o).

Question 19

L112: What treatment options are there for treating affected molars?

Answer 19

• Composite/ GIC restorations;
• Stainless steel crowns;
• Adhesively retained copings;
• Extraction (8.5-9.5 y/o).

Question 20

L112: What should you consider before extracting a affected molars in children?

Answer 20

• Age;
• Skeletal pattern;
• Future orthodontic needs;
• Quality of teeth e.g. caries.

Question 21

L112: What treatment options are there for treating affected incisors?

Answer 21

• Acid pumice micro abrasion;
• External bleaching;
• Localised composite placement;
• Full composite or porcelain veneers.