Molar Incisor Hypomineralisation and other Dental Defects Flashcards
What is the clinical appearance of Dentinogenesis Imperfecta & Dentine Dysplasia?
Affects either the primary or both dentitions.
Amber,brown/blue or opalescent brown in colour
Enamel wear
Define molar incisor hypomineralisation
Hypomineralisation of systemic origin, presenting as demarcated, qualitative defects of enamel of first permanent molars frequently associated with affected incisors
Comment on the difference in lesion location in MIH vs Caries
MIH
Lesions occlusal, buccal and/or palatal
Caries
Lesions in fissures or mesially/distally
MIH can increase the risk of other dental anomolies what are they?
- Increased risk of hypodontia (most commonly lower second premolars)
- Ectopic first permanent molars (erupt more mesially)
- Primary molar infraocclusion (teeth not rose to occlusion)
- Macrodont and microdont teeth
What is the radiographic appearance of Dentinogenesis Imperfecta & Dentine Dysplasia?
Bulbous crowns
Small or obliterated pulp chambers
Roots are often narrow with small or obliterated root canals
Comment on the predicatability of space closure for upper and lower molar extractions
Upper molars: predictable space closure
Lower molars: careful consideration
Comment on the link between primary teeth and MIH
MIH doesnt affect the primary teeth therefore parents are always shocked when their children have MIH in permanent teeth due to their appearance
Sometimes can affect primary 2nd molars
Comment on the appearance of opacities for MIH teeth
Colours can be the following:
White, Cream, Yellow, Brown
Lesions can be diffuse or well demarcated
At what stage in a childs life are systemic factors meant to be causative or contributing factors to MIH?
Last gestational trimester and first three years of life
Comment on the enamel of hypomineralised AI teeth
AKA Hypocalcified Type III
The enamel is soft and may be lost soon after eruption leaving the crown composed only of dentin
What do the number of affected teeth suggest about the systemic disturbance for MIH?
The number of affected teeth was associated with the time when the potential systemic disturbance occurred
(prenatal (more teeth), perinatal, postnatal)
What is chronological hypoplasia?
Reduced quantity of enamel leading to pits and staining
MIH lesions are localised and assymetrical what does this suggest about its origin?
Suggests a systemic origin
When is a good time to extract lower molars affected by MIH?
Chronological Age 8-10 years
Upper lateral incisors erupted
2nd premolars not yet erupted
What are the associated features of amelogenesis imperfecta?
Taurodontism
Delayed eruption
Anterior Open Bite
Pre-eruptive resorption
Periodontal disease
Enlargement of pulp chambers with more apical furcation
According to the Royal College of Surgeons guidelines 2014 when would you extract a first permanent molar affected by MIH?
In cases where prognosis is poor, extraction is an option
(Due to lesion asymmetry, balancing and compensating extractions may be indicated)
Comment on the prevalance of MIH in molar teeth compared to incisors
Risk of incisor defects increase the more molars are affected
What are the treatment options for MIH posterior teeth?
Restorations - GIC or Composite
Preformed Metal Crowns
Indirect onlays - Non-precious metal, gold or tooth-coloured
In which teeth is post-eruptive breakdown most common in MIH patients?
Molar teeth
What is the prevalence of MIH in the UK for 12 year olds?
16% of 12 year olds
What are the suggested possible causes for MIH?
Respiratory tract infections
Use of antibiotics
Perinatal complications
Dioxins
Oxygen starvation
Low birth weight
Calcium and phosphate metabolic disorders
Frequent childhood diseases
What is dental fluorosis?
Hypomineralisation of enamel resulting in white opaque appearance caused by excessive fluoride intake
How do you treat chronological hypoplasia?
Fill in the pits with composite
Polish and use microabrasion for staining
When extracting a first permanent molar due to MIH do you need a compensating extarction? (upper or lower)
Extract at 8-10 before second permanent molar erupts;
Upper FPM: Do not compensate
Lower FPM: Compensate
What is this an example of?
Chronological hypoplasia
What is the most common cause of chronological hypoplasia?
Vitamin D deficiency
What teeth does amelogenesis imperfecta effect?
All teeth including primary teeth
What is hypoplastic AI?
Type I
The enamel thickness varies from thin and smooth to normal, with grooves, lines and/or pits
Teeth are thin and rough
What are the treatment options for MIH anterior teeth?
Bleaching
Microabrasion
Etch bleach seal
Infiltration
Composite restorations/veneers
Porcelain veneers
What are some clinical problems you may face in patients with MIH?
- Post-eruptive enamel breakdown → dentine exposure → pulp involvement
- Tooth sensitivity, which might lead to poor oral hygiene
- Local anaesthesia problems related to chronic pulp inflammation
- Behavioural management issues
- Aesthetics
- Tooth loss
- Multiple Appointments
What stages of amelogensis are proposed to be affected for MIH?
Early maturation stage or Late secretory phase
What clinical problems can post-eruptive breakdown lead to?
Post-eruptive enamel breakdown → dentine exposure → pulp involvement
