MIH BDS2

Question 1

Molar Incisor Hypomineralisation (MIH)

Answer 1

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

Question 2

Appearance

Answer 2

cheesy molars, enamel not form properly, overlying issue with caries, post eruptive breakdown

Question 3

Anterior teeth

Answer 3

marks on upper and lower central and laterals

Question 4

Prevalence of MIH

Answer 4

10 - 20%

Question 5

Hypomineralisation

Answer 5

• disturbance of enamel formation resulting in reduced mineral content
• weaker bonding to COMP as less mineralised enamel

Question 6

Hypoplastic

Answer 6

• reduced bulk/ thickness of enamel; not the right shape
  1. true: enamel never form
  2. acquired: post- eruptive loss of enamel bulk; hypomineralised bits fall off

Question 7

Is there an underlying pulpal inflammation in MIH teeth?

Answer 7

1. pulpal innervation; increase in neural density (green)
2. immune cells; increase in immune cell accumulation (red)
3. vascularity; increase if sensitive MIH tooth (blue)

Question 8

Theories of why MIH sensitive?

Answer 8

1. Dentine hypersensitivity; porous enamel/ exposed dentine facilitates fluid flow within dentine tubules - activate AD nerve fibres
2. Peripheral sensitisation; underlying pulpal inflammation; sensitisation of c fibres
3. Central sensitisation; nociceptive input

Question 9

What causes MIH?

Answer 9

• unclear diagnostic criteria
• most parents cant remember details from 8-10 yrs
• variations in quality and completeness of case records
• study populations small

Question 10

What’s the critical period for formation of MIH?

Answer 10

• first year of life
• enamel crown of FPM is complete by one year
• developmental problem / environment, not genetic

Question 11

Questions to parents regarding time frame?

Answer 11

1. Pre- natal
2. Natal
3. Post- natal, up to age of 2

Question 12

Aetiology of Prenatal ?

Answer 12

• no causative causes
• usually ask mothers about their general health in 3rd trimester of pregnancy
• may have pre-eclampsia/ gestational diabetes

Question 13

Aetiology of perinatal?

Answer 13

• birth trauma/ anoxia (baby stuck and lack of oxygen)
• hypocalcaemia
• preterm birth

Question 14

Aetiology of post- natal?

Answer 14

• prolonged breast feeding
• dioxins in breast milk
• fever and medication (NOT USUALLY BECAUSE OF AB, BUT THE WAY CHILD TAKING IT)
• socioeconomic status

Question 15

Viral infection - Measles

Answer 15

• incubation period: 10-14 days
• fever
• rash
• Koplik’s spots - white spots
• Conjunctivitis
• Coryza- funny nose
• cough
  duration of illness 7-10 days
• secondary infection, eg: otitis media, bronchopneumonia
• corneal ulcer, stomatitis, gastroenteritis, appendicitis

Question 16

Symptoms of Rubella?

Answer 16

• mild fever
• maculopapular rash
• generalised lymphadenopathy, eg: suboccipital nodes; DO E/O exam
• malaise
• URTI: upper respiratory tract infections
• 8-10 days
• encephalitis, arthritis, purpura

Question 17

Symptoms of Chicken Pox (Varicella)

Answer 17

• low grade fever
• rash
• crops of spots progressing from macule- papule - vesicle rupture
• 6-10 days of illness

Secondary infection of lesions
- encephalitis
- pneumonia

Question 18

What does yellow/ brown staining mean?

Answer 18

• more porous
• affecting whole enamel layer

Question 19

What does white/ cream mean?

Answer 19

• affecting inner parts of enamel affected
• important to know for tx wise whether to go for microabrasion/ ICON

Question 20

Clinical Problems of MIH

Answer 20

1. loss of tooth substance
   - breakdown of enamel
   - toothwear
   - secondary caries
2. sensitivity; posterior > anterior
3. appearance

Question 21

What are the tx options for Molars?

Answer 21

• COMP/GIC restorations
• SSC
• adhesively retained copings
• extraction (8.5- 9.5 yrs old)

Question 22

Molar with Post- eruptive breakdown

Answer 22

with GI

Question 23

Extraction of HFPM

Answer 23

Consider
- age
- skeletal pattern
- future orthodontic needs
- quality of teeth, eg: caries

Question 24

What is the right time of removal of lower FPM?

Answer 24

• calcification of bifurcation of 7’s on radiograph
• we know if we remove, then the space will close with the 7’s

Question 25

When to remove upper FPM?

Answer 25

- not that critical - normally the 7's may drift and occlude with lowers - to resolve crowding at the anteriors when ortho

Question 26

What are the tx options for affected incisors?

Answer 26

- acid pumice microabrasion - resin infiltration - external bleaching - localised composite placement - full comp veneers - full porcelain veneers only after 20 yrs old to make sure gingival margins levels are more settled