MIH

Question 1

What is MIH?

Answer 1

hypomineralisation of systemic origin or one or more of the four permanent first molars as well as associated and affected incisors

Question 2

What is the prevelance of MIH?

Answer 2

3.6-25% Weerhijme 2001§

Question 3

How does MIH present?

Answer 3

affects one more more FPM and incisors
demarcated patches
white brown and cream
post eruptive breakdown
missing 6's
heavily restored abnormal restorations 
calculus

Question 4

WHat are the alternative terms to MIH?

Answer 4

cheese molars
hypomineralised 6’s
idiopathic hypomineralisation
non fluoride hypomineralisation

Question 5

Differential diagnosis?

Answer 5

fluorosis
AI
Turner tooth
Idiopathic hypomineralisation

Question 6

When does tooth formation begin?

Answer 6

6 weeks IU

Question 7

What is the structure of enamel?

Answer 7

Unique
Organised tightly packed crystals
Highly mineralised 95% HAP

Question 8

What are the phases of enamel production?

Answer 8

Sectretion

maturation

Question 9

what is the first phase of amelogenesis?

Answer 9

Odontoblasts secrete collagen type 1
Then amelobalats differntiate in the internal enamel epithelium and they secrete enamel proteins which change shape and leads to mineralisation

Question 10

What is the purpose of the secretoy phase?

Answer 10

defines the tooth form
deposition of organic matrix and amll thin crytsallites
there is an incremental growth in thickeness

Question 11

t/f the secretory phase is a contrinuous process

Answer 11

F

Question 12

What does a faiulre in the secreotry phase leasd to?

Answer 12

hypoplasia

this leads to small pits and grooves and gross enamel surface defects

Question 13

What happens during the maturation phase of amelogenesis?

Answer 13

this is wehrre the quality of the tooth is established and the organic matrix is degraded and becomes minerlaised

Question 14

What do ameloblasts do to calcium and phospate ions during maturation?

Answer 14

they move them

Question 15

t/f the matrutration process is a contunous orocess post eription?

Answer 15

t

Question 16

what happens to the ameloblasts following maturation?

Answer 16

apoptosis

Question 17

What does failure in the maturation process lead to?

Answer 17

hypomineralisation

Question 18

what is hypomineralisation?

Answer 18

this is when there is poor mineralisation of the enamel matrix and occurs later in development

Question 19

What kind of enamel defect does hypomineralisation lead to?

Answer 19

this leads to white and brown opacities

Question 20

t/f hypomineralised enamel is normal thickness?

Answer 20

T

but enamel is poor quality

Question 21

What does hypomineralised enamel appear like down a microscope?

Answer 21

altered Ca/P balance withless distinct enamel rods and there is bacterial penetration into the enamel rods and it has a lower hardness than normal enamel

Question 22

How does MIH occur?

Answer 22

not sure
many factors 
timing of the insult
pyrexia
hypocalcaemia
hypoxia of child or mother?

Lygidakis 2008

Question 23

according to Crombie et al 2009 what is the aetology of MIH?

Answer 23

systematic review
exposiure to chemical: breasfeeding and fluride
peri natal and neonatal problems: malnutrituion, maternal health, birth problems
common child hood illness and mdeically compormised children: respiratory problms, otitis media, coeliac, renal, CF

Question 24

T/F breastfeeding is protective against MIH?

Answer 24

T crombie et al 2009

Question 25

What is the effect of early cessation of breast feeding and malnutrition on MIH?

Answer 25

this can lead to MIH | crombie 2009

Question 26

WHat is the effect of fluoride on MIH?

Answer 26

there is weak evidence and leads to more diffude defects | Crombie 2009

Question 27

What does it mean if there are visible defects in E's? ref

Answer 27

Crombie et al 2009 | co existing factoirs

Question 28

How strong is the evidence for childhood illnesses and MIH link

Answer 28

Poor link poor parental recall confounding factors

Question 29

What are the patient related challenging factors?

Answer 29

appearance:children and parents concenred about appearance, transition to secondary school sensitivity: greater innneravtion of te subodontoblastic pulp horn regions, increased immune cell density, increased vascularuty in sensitive teeth, porous enamel causes dentine to become exposed, activation of A delta fibres. and increase C fibre action Behaviour management: young pateints, repeated restrations, LA, fears

Question 30

What are the restorative callanges?

Answer 30

incisors: site, colour, bonding, immature dentine, crumbly molars: size, bonding, caries develpment, poor progmosis, immature dentine, difficult to anesthetise, crumbly, over eruption of molars

Question 31

WHat are the solutions for the molars?

Answer 31

``` Phase 1: surveillance, recognise and review Phase 2: desens phase 3: temporarise, phase 4: restore, extract, orthodontic phase 5: maintenance ```

Question 32

What does surveillance entail?

Answer 32

``` knowledge of prevalnce of the diease hypomin and plasia of primary teeth past medial history family histry review as teeth erupt ```

Question 33

WHat does recognition and review entail?

Answer 33

consider differntial diagnosis review according to caries risk status and abscence of problems implement prevetativ regimen

Question 34

WHat preventative techniques are there?

Answer 34

``` fluroide desensitising toothpaste CPP-ACP fissure sleants OH ```

Question 35

How do you temporaise MIH teeth?

Answer 35

GIC, SSC

Question 36

when would you restore or extract MIH teeth?

Answer 36

repemds on the extent of damage and consider the structure of the female and age of child, presence of adjacent teeth and consider oclusal and orthodontic factors

Question 37

What can you rstore molars with?

Answer 37

composite SSC GOld or Cobalt Chrome onlays

Question 38

WHat are the advanatges of using SSC?

Answer 38

good longevity easy to fit occlusion dimesnion settles

Question 39

What are the advantages and dis of using fabricated onlays?

Answer 39

well tolerated good longevity permanents BUT: time and lab bill

Question 40

WHen would you xla MIH teeth?

Answer 40

poor prognosis age dependant eg dependant on formatio of 7 are 7's and 8's present? MUST CONSULT ORTHO

Question 41

WHat are the options for incisors?

Answer 41

``` microabrasion etch bleach seal bleach composite bleach and comp ```

Question 42

HOw does microabrasion work?

Answer 42

imprives surface discolouration which is limited to the outer surface only 100nm enamel is removed and can only be used for mild lesions brown stains more easily removed than white

Question 43

WHat do you use in microabrasion?

Answer 43

pumice and HCL

Question 44

WHat do you use in etch bealch and seal?

Answer 44

60s etch and use 5% NAOCl bleach for 5-10mins and then re etch the tooth and apply clear fissure sleant

Question 45

What type of bleaching agents should you use?

Answer 45

localised yellow brown patches: sodoum hypochlorite | darker lesions: peroxide

Question 46

WHen are cast restoratons and comoposte done in MIH?

Answer 46

permanent teeth | cast used for seevre cases