Enamel/dentine defects

Question 1

What is enamel hypoplasia? What is its pathogenesis? (3)

Answer 1

“Enamel hypoplasia is a defect of the teeth in which the enamel is deficient in amount” Pathogenesis linked to genetics, infection, trauma or medications that impair tooth mineralization, calcification or maturation.

Question 2

Difference between enamel hypoplasia and hypomineralization (1)

Answer 2

Hypoplasia: defect in the quantity of enamel – lesser enamel than normal
Hypomineralisation: defect in the quality of the enamel (softer)

Question 3

List four etiological causes of enamel hypoplasia (2)

Answer 3

Genetics; Environmental (trauma, infection, drugs)

Question 4

What is MIH (molar incisor hypomineralisation)? (2)

Answer 4

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

Question 5

List 6 clinical problems of MIH. (3)

spot LA

Answer 5

• Tooth Sensitivity, which might lead to poor oral hygiene and therefore, caries susceptibility increases
• Post-eruptive enamel breakdown leading to dentine exposure and this makes the tooth at risk of pulp involvement
• Occasional eruption difficulties of molars due to enamel roughness
• Tooth loss
• Local anaesthesia problems which are possibly related to chronic pulp inflammation
• Aesthetic problems in anterior teeth
• Behavioural management problems due to dental fear and anxiety which is related to the pain experienced by the patients during multiple treatment appointments
• Negative impact on the child’s school performance due to the absence from school
• Financial concerns for families.

Question 6

Describe and explain the management of 10 year old child with hypoplastic permanent 1st molars. (5)

Answer 6

Preventive measures – OHI, diet, desensitizing toothpaste

Treatment options for molars
• Resin infiltration (material = Icon by DMG) – penetrates demineralized enamel
• Resin composite – just remove the porous enamel
• Preformed metal crowns
• Extraction (for poor prognosis)

Treatment options for incisors
•	Microabrasion
•	Tooth bleaching + tooth mousse
•	Etch-bleach-seal technique (to remove yellow stains) (seal = fissure sealant or bonding)
•	Resin infiltration
•	Composite restoration or veneers
•	Porcelain veneers

Question 7

Give two reasons for localized hypoplasia and one syndrome associated with generalized hypoplasia (3)

Answer 7

Localised hypoplasia: nutrition (e.g. calcium deficiency of the mother) , trauma during birth; prematurity of child;
Syndrome associated with generalized hypoplasia: Treacher Collins syndrome

Question 8

List 4 problems caused by Enamel Hypoplasia. (2)

Answer 8

Aesthetics, dental caries, sensitive to heat and cold, easy to get periodontal disease

Question 9

Management of patient with Enamel Hypoplasia (3)

Answer 9

Resin composite filling, resin-bonded sealant, crowns, enamel microabrasion

Question 10

List 2 disturbances of chronological hypoplasia (2)

Answer 10

(Chronological hypoplasia = linear enamel hypoplasia) multiple, symmetrical, chronological pattern, linear, ring-like pattern involving all surfaces of tooth

Environmental insult, such as infection (e.g. measles), drugs

Question 11

2 differential diagnosis of hypoplastic tooth (2)

Answer 11

Amelogenesis imperfecta; fluorosis

Question 12

2 major clinical problems associated with hypoplasia (2)

Answer 12

Aesthetics, sensitivity