Holistic treatment planning for children with molar incisor hypomineralisation

Question 1

Definition of MIH (2)

Answer 1

A clinical diagnosis to describe:
 “hypomineralisation of systemic origin of one to four first permanent molars, frequently associated with affected incisors”
'Idiopathic hypomineralisation'
'Cheese molars'
'Popcorn molars'

Question 2

Hypomineralisation vs hyploplasia

Answer 2

Hypomineralisation: qualitative disturbance in enamel formation
Hypoplasia; quantitative disturbance in enamel formation

Question 3

Clinical presentation of MIH (6)

Answer 3

Affected molars present with well-demarcated white/yellow or brown/yellow enamel opacities
1-4 FPMs may be affected, conflicting data as to whether maxillary or mandibular teeth more at risk
In severe cases, defective enamel is lost soon after eruption to expose underlying dentine
Affected incisors also present with well-demarcated white/yellow or brown/yellow enamel opacities

Post-eruptive enamel loss is not usually a feature

Increased risk of hypomineralised incisors where molars are more severely affected

Question 4

World wide prevalence of MIH (2)

Answer 4

Meta-analysis published 2018 found a global prevalence of 13% (Schwendicke et al)

Question 5

Pre-natal aetiology of MIH (9% of MIH cases) (6)

Answer 5

Maternal pyrexia
Medication (antibiotics)
Prolonged vomiting
Maternal diabetes
Vitamin D deficiency
In vitro fertilisation

Question 6

Peri-natal factors in aetiology of MIH (34% of MIH cases) (4)

Answer 6

Caesarean section
Prolonged/complicated delivery
Prematurity/low birth weight
Twins

Question 7

Post-natal factors in aetiology of MIH (34% of MIH cases) (6)

Answer 7

Ear/nose/throat infections
Respiratory problems
Pyrexia
Seizures
Urinary infections
Antibiotics

Question 8

Aetiology of MIH (4)

Answer 8

Most ‘causes’ seem to be associated with hypocalcaemia and hypoxia
May also involve a genetic susceptibility?
No obvious causes in 10-24% of MIH patients (Jalevik & Noren, 2000)
Conflicting findings regarding role of environmental pollutants such as dioxins (Laisi et al., 2008)

Question 9

MIH: underlying mechanisms (5)

Answer 9

Insult to enamel formation from around 37 weeks to 3 years
Transitional and maturation phase of enamel affected
reversible or irreversible damage to ameloblasts with qualitative disturbance to enamel formation
Protein retention and poor hydroxyapetite crystal formation
Low content of calcium and phosphate ions

Question 10

MIH lab studies: enamel (3)

Answer 10

Porous
Weak
Poor etch pattern

Question 11

MIH lab studies: dentine (2)

Answer 11

Sparse reparative dentine and irregular globular dentine

Influx of bacteria in dentine tubules

Question 12

MIH lab studies: pulp (3)

Answer 12

Underlying chronic pulpal inflammation

Increased immune cells, vascularity and neural density

Question 13

MIH clinical challenges: pt related factors (4)

Answer 13

Extreme tooth sensitivity
Aesthetic concerns
Anxious about dental treatment (Jalevik and Klingberg, 2002)
Need for long-term interventions (financial burden)

Question 14

MIH clinical challenges: clinical related factors (4)

Answer 14

Difficulty in achieving adequate level of analgesia for restorative treatment
High failure rate for adhesive restorations and sealants (poor shear bond strength)
Tooth tissue loss
High caries experience

Question 15

MIH: holistic care for children (4)

Answer 15

I. Prevention, remineralisation, alleviation of symptoms
II. Treatment planning for first permanent molars
III. Improvement of incisor aesthetics
IV. Incorporating a child-centred approach

Question 16

DDE: prevention is the first principle of care (4)

Answer 16

Aim to remineralise, alleviate symptoms, improve oral hygiene and diet, reduction in caries risk

Question 17

Tooth mousse (4)

Answer 17

Marketed for re-mineralisation of enamel since 1996
Delivery system for bio-available calcium and phosphate ions
Patient-application daily in trays or locally to affected tooth
May improve sensitivity symptoms, appearance and structure of DDE (Baroni and Marchionni, J Dent Res, 2010)

Question 18

Fissure sealants, including clinical tips (4)

Answer 18

Fissure sealants are recommended - but have high failure rates in hypomineralised enamel (only 25% survival at 4-years, Lygidakis et al., 2009)
Pre-use of 5% sodium hypochlorite to remove protein content has been recommended (Mathu-Muju & Wright, 2006)
Clinical tips
Use of warm water and cotton pledgets to remove etch and avoid aspirators
Use of light cured glass ionomer sealants (FUJI TRIAGE)

Question 19

First permanent molars with DDE: options (3)

Answer 19

Review/ prevention
-topical fluoride applications
-tooth mouse
-fissure sealants
Restore (short, mid or long term)
-adhesive restorations
-preformed metal crowns
-laboratory formed crowns
Extract
-LA/ IS/ GA
-need for compensating extractions
-ortho considerations
-ideal age 9.5/ 10

Question 20

First permanent molar extraction - too early vs too late

Answer 20

Too early - spacing between lower premolars or distal impaction of lower second premolar against lower second molar
Too late - mesial tipping of lower second permanent molars

Question 21

Definitely seek an ortho opinion for (4)

Answer 21

Class II cases
Class III cases
Hypodontia cases
Severe crowding cases

Question 22

Restoration of PMCs: choice of materials (5)

Answer 22

Resin-modified glass   ionomer
Composite resin
Amalgam :(
Preformed metal crowns
Cast onlays/crowns

Question 23

Adhesive restorations (2)

Answer 23

GICs are useful as a short-term restoration prior to definitive restoration or extraction (e.g Fuji Triage, GC America Inc)
Composite resins – only indicated for mildly affected teeth with no cuspal involvement –margins of restoration should extend beyond visibly affected enamel

Question 24

Preformed metal crowns: mid-term restorations (2-5 years) - advantages (5)

Answer 24

Prevent further tooth deterioration/caries
Controls tooth sensitivity
Establish correct interproximal contacts and occlusal relationships
Not as technique-sensitive or costly as cast restorations
Quick
-tip - use of elastic separators may obviate need for interproximal tooth preparation

Question 25

Preformed metal crowns: mid-term restorations (2-5 years) - disadvantages (4)

Answer 25

Adverse reactions in patients with a nickel allergy
Production of anterior open bite if not fitted correctly
Gingival inflammation
Not a permanent restoration

Question 26

Cast restorations (3)

Answer 26

Indirect gold onlays - are the restoration of choice for moderate or severe hypomineralisation where the maintenance of FPMs is indicated in the long term

Placement is usually considered in the late mixed or early permanent dentition

No significant differences in successful outcome of cast metal crowns vs PMCs in children with enamel defects (Zagdown et al., 2003)

Caution with conventional full crowns! Immature teeth have short crowns, large pulps and the procedure is highly destructive to tooth tissue

Question 27

What are the options for clinical (aesthetic) management of anterior teeth (4)

Answer 27

Tooth whitening
Micro-abrasion
Composite resin (direct/ indirect)
Resin infiltration (ICON)