molar incisor hypomineralisation

Question 1

molar incisor hypomineralisation

Answer 1

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

Only teeth MIH effects (first permanent molar and incisors)

Cheesy molars
- Yellow
- Obvious
Can be patches of yellow or white

Question 2

molar appearance of molar incisor hypomineralisaton

Answer 2

Cheesy molars
- Yellow
- Obvious
Can be patches of yellow or white

Question 3

incisor appearance of MIH

Answer 3

Well demarcated - blobs rather than diffuse
- Not symmetrical

Chalky white and yellow/brown parts

Question 4

prevalence of MIH

Answer 4

10-20%

- increasing

Question 5

hypomineralised

Answer 5

disturbance of enamel formation resulting in a reduced mineral content
later in amelogenesis

• secretory – jelly template
  no issues, right shape
• mineralisation – jelly to hard enamel
  —-issue here – parts not as strong

cannot bond normally
- different structure to normal enamel, weaker areas

Question 6

post-eruptive hypoplasia

Answer 6

hypomineralised FPMs erupt normal bit with soft enamel, parts fall out – then believe wrong morphology
- think hypoplastic but not truly

Question 7

bonding issue in MIH

Answer 7

cannot bond normally

- different structure to normal enamel, weaker areas

Question 8

what stage of amelogeneisis is affected in hypomineralisation

Answer 8

mineralisation (after secretory stage)

- enamel not as strong

Question 9

hypoplastic

Answer 9

reduced bulk or thickness of enamel
- erupt amorphous (wrong shape - secretory phase wrong, but later mineralisation stage right)

May be:
- True - enamel never formed
- Aquired - post-eruptive loss of enamel bulk
\

Question 10

bonding to hypoplastic enamel

Answer 10

Bond normally

normal enamel structure but not full coverage

Question 11

what stage of amelogenesis is effected in hypoplastic enamel

Answer 11

wrong shape - secretory phase wrong, but later mineralisation stage right

Question 12

why so difficult to determine aetiology of MIH

Answer 12

Unclear diagnostic criteria in classification

Most parents can’t remember details from 8-10 years before
- FPM begins forming before birth to age of 2 - Long time period ago

Variations in quality and completeness of case records

Study populations small

Question 13

what is the critical period for formation of MIH

Answer 13

First year of life generally agreed (disturbance)
- Developmental (not hereditary, or genetic)

Enamel matrix of crown of FPM’s is complete by one year

Question 14

3 clinical periods of enquiry for MIH

Answer 14

prenatal

natal (perinatal)

postnatal

Question 15

questions to ask regarding prenatal period and MIH

Answer 15

Usually ask mothers about their general health in 3rd trimester of pregnancy
- Usually nothing really identified but possible causes can be e.g. Pre-eclampsia, gestational diabetes

no definitive causative factors identified

Question 16

questions to ask regarding perinatal period and MIH

Answer 16

Birth trauma/anoxia
- particularly traumatic - emergency C section, suction cup, forceps, lack O2

Hypoclacemia

Preterm birth
- higher MIH rate than full term

Question 17

questions to ask regarding postnatal period and MIH

Answer 17

Prolonged breast feeding (beyond 6 months)
- 50:50 inconclusive, don’t suggest don’t breast feed to avoid

Dioxins in breast milk
- 1 yes:2 no

Fever and medications (childhood infections: mumps, chicken pox etc)

• 100% yes
• antibiotics not cause enamel defect but reason on them does

Rural Vs Urban
- Yes

special care units, respiratory problems

Question 18

measles Incubation period:

Answer 18

10-14 days

Question 19

measles symptoms (6)

Answer 19

Fever
Rash
Koplik’s spots
Conjunctivitis (eye – need sunglasses)
Coryza (runny nose)
Cough

Question 20

measles Duration of illness

Answer 20

7-10 days

Question 21

measles complications

Answer 21

Secondary infection, otitis media (middle ear infection)

bronchopneumonia

Corneal ulcers, stomatitis,

gastroenteritis, appendicitis

Question 22

rubella symptoms (5)

Answer 22

mild fever

Maculopapular rash

Generalised lymphadenopathy (swollen gland)
esp. suboccipital nodes

Malaise tired

URTI

Question 23

rubella duration of illness

Answer 23

8-10 days

Question 24

rubella complcations

Answer 24

rare

Encephalitis - brain swelling arthritis - join swelling
Purpura - severe rashes

Question 25

what has been found to be a possible aetiological cause of MIH

Answer 25

Disturbances in nutrition during the first 6 months that may have an effect on MIH Breastfeeding more > 6months Late intro gruel > 6months Late intro infant formula >6months systemic disturbances in first 2 years of life has an impact

Question 26

depth of effect if appearance is yellow/brown enamel

Answer 26

whole enamel layer MIH | - microabrasion

Question 27

depth of effect if appearnace white/cream enamel

Answer 27

inner parts of enamel affected | - bleaching so less contrast with normal tissue

Question 28

content of hypomineralised demarcated opacities

Answer 28

Higher carbon content, lower Ca, PO4

Question 29

what is neural density like in MIH

Answer 29

Significant increases in neural density (nerve tissue) in the pulp horn and subodontoblastic region of MIH samples More innervation - more sensitive, - harder to anaesthetise, more neural densities

Question 30

is there a difference in immune cell accumulation in MIH teeth

Answer 30

yes Significant increases in immune cell accumulation in MIH samples, especially with post-eruptive enamel loss

Question 31

is there a difference in vascularity in MIH teeth

Answer 31

yes significant increase in vascularity in sensitive MIH teeth - try and fix issue with more blood flow

Question 32

3 potential pain mechanisms of MIH

Answer 32

dentine hypersensitivity peripheral sensitisation central sensitisation DO NOT KNOW MIH PAIN MECHANISM EXACTLY - know they are more sensitive

Question 33

dentine hypersensitivity in MIH

Answer 33

porous enamel or exposed dentine facilitates fluid flow within dentine tubules to activate A-delta nerve fibres - hydrodynamic theory

Question 34

peripheral sensitisation in MIH

Answer 34

underlying pulpal inflammation leads to sensitisation of C-fibres - more neural C fibres there in first place

Question 35

central sensitisation in MIH

Answer 35

from continued nociceptive input | - come from brain, due to continue assault on teeth

Question 36

3 clinical problems due to MIH

Answer 36

``` Loss of tooth substance - Breakdown of enamel - Tooth wear - Secondary caries (Perfectly good primary dentition, FPM 6 months has caries – poor caries resistance) ``` Sensitivity - Can be exquisitely sensitive - ----More caries as hurt to brush Appearance (esp anterior, psychological issues)

Question 37

MIH treatment options (4)

Answer 37

Composite/GIC restorations - Make them tougher and more wear resistant Stainless steel crowns Adhesively retained copings - Au, glass, composite Extraction (8.5 - 9.5 yrs) - majority of moderate to severe – use their dental age

Question 38

what do you need to see radiographically to extract FPMs

Answer 38

Want to see calcification of bifurcation of lower 7 than can extract lower 6s - Before 7 erupts will drift forwards Take out upper 6s at same time - Need to so don’t over erupt - Potentially crowded – loss of space due to primary molars extraction, keep upper 6s till 7s come through as risk of losing good premolars for space - Longer ortho treatment but more natural teeth

Question 39

4 considerations for extractions of HFPMs

Answer 39

age (dental age) skeletal pattern (prevent future ortho problems) future othrodontic needs quality of teeth e.g. caries

Question 40

5 treatments of affected hypo-mineralised incisors

Answer 40

Acid pumice microabrasion - Yellow or brown marks removed External bleaching - Cant get white chalkiness to go away, but can reduce contrast with rest of tooth Localised composite placement - Less likely to eradicate but make less difference between Full composite veneers Full porcelain veneers - Gum level changes between 16 and 20 – so avoid as expose margins and wear tooth down

Question 41

what is required for microabrasion and external bleaching

Answer 41

full permanent dentition | - 11-13 yrs