Molar and Incisor Hypomineralisation Flashcards
What is enamel hypomineralisation?
A qualitative defect of tooth steructure resulting in opqcities witin the enamel.
It is the result of a disturbance to ameloblasts during the calccification and maturation stage of tooth development.
What is enamel hypoplasia?
A quantitative defect of tooth structure which ranges from minor pits to grooves to total absence of enamel.
It normally results from the disruption of ameloblasts during the secretory stage.
What is molar hypommineralissation (MH)?
Hypomineralisation of one to four first permanent molars with no affected incisors.
What factors can disrupt ameloblast function?
Inccreased temperature, hypoxia, hypocalcaemia, pH levels
Systemicc disturbances within the first 2 years of life are most likely to cause chronilogical hypomineralised enamel defects
What are some local causes of enamel hypoplasia/ hypommineralisation?
Trauma of primary predecessor Infection of primary predecessor Laryngeoscopy Trauma due to extraction of primary predecessor Repaired cleft lip and palate
What are some systemic factors that can cause enamel hypoplasia/ hypomineralisation?
1) Severe metabolic disturbances
2) Premature birth and low birth weight
3) Excessive ingeestion of fluoride
4) Nutritional deficiencies
5) Brain injuries and neurological deficiencies
6) Haemotological disorders
How can enamel hypommineralisation be diagnosed clinically?
Opacities have a clear and distinct border to the adjacent enamel
Abnormality in the transluccency of enamel
What are some dental problems associated with enamel hypoplasia?
1) Inccreased susceptibilty to caries
2) Inccrease in anxiety
3) Difficulty obtaining appropriate local aneasthesia (may need to top up with articaine bucally)
What are the clinical implications of hypomineralised enamel?
There is an increased oocccurance of enamel fractures
Retention of adhesive materials is decreased hence decreased success of restorative work.
How does the pulpal histology of hypomineralised teeth differ form that of normal teeth and why is this important?
There is signnificantly greater innervation density in the pulp horn and subodontoblastic regions.
This supports the hypothesis that a subclinical pulpal inflammation could lead to hypersensitivity in MIH teeth.
What is the 6 step approach for mannaging HM/HP teeth as propossed by Williams, 2006?
1) Risk identification
2) Early diagnosis
3) Remineralisation and desensitisation
- as soon as tooth erupts (topical F +/- CPP-ACP)
- dentine bonding agents
4) Prevention of dental caries and post-eruptive breakdown
5) Restoration or extraction
6) Maintainence
What kind of restorative options are there for HM/HP teeth?
Intermediate restorations: -> GIC, direct or indirect CR, SSC Transitional/permmanent restorations: -> SSC -> Cast restorations Primary molars: extract of SSC Permanent mmolars: full coronal restorations
If extraction of lower 6’s are to be carried out, when would be the most ideal time?
When the crown of the 7 is just formed, and when the bifurcation of the roots is just visible.
