Anomalies (including Numerical, Enamel and Dentine Defects) Flashcards
What are the most commonly missing teeth ?
3rd molars
Lateral incisors
Lower premolars (5s).
What are most likely to be missing - permanent vs. primary teeth ?
Permanent.
What two teeth in the permanent dentition are least likely to be missing ?
First permanent molars.
Upper central incisors.
What are examples of conditions which cause a predisposition to hypodontia ?
Ectodermal dysplasia.
Down syndrome.
Cleft palate.
Hurler’s syndrome.
Is hyperdontia more common in males or females ?
Males
Is hyperdontia more common in maxilla or mandible ?
Maxilla
What medical condition causes predisposition to hyperdontia ?
Cleidocranial dysplasia.
What are the four types of supernumerary teeth ?
Conical.
Tuberculate.
Supplemental.
Odontome.
Define an odontome.
Irregular mass of dental hard tissue, compound or complex.
Name some examples of dental anomalies associated with size and shape of the teeth.
Microdontia.
Macrodontia.
Double teeth.
Odontomes.
Taurodontism.
Dilaceration of crown or root.
Accessory cusps.
Peg laterals.
What are three potential causes of short root anomaly ?
Radiotherapy.
Dentine dysplasia.
Accessory roots.
Asian populations.
Downs syndrome.
What tooth is most likely to be affected by short root anomaly ?
Permanent maxillary incisors.
Name three general enamel anomalies ?
Amelogenesis imperfecta.
MIH.
Environmental/localised enamel hypoplasia.
What are two causes of localised enamel hypoplasia ?
Trauma.
Infection of primary predecessor.
What are the four causes of environmental enamel hypoplasia ?
Systemic.
Nutrition.
Metabolic - Rhesus incompatibility, liver disease.
Childhood infection - measles.
What are the four main forms of amelogensis imperfect ?
Hypoplastic.
Hypocalcified.
Hypomaturational.
Mixed forms.
How might a hypomineralised tooth present ?
With white, yellow or brown lesions.
All tooth tissue present.
Define hypomineralisation.
Under mineralised tooth with normal tooth structure.
Secretory phase unaffected.
Mineralisation phase disrupted.
Define hypoplastic.
Abnormal tooth structure with normal mineralisation.
Secretory phase disrupted.
Mineralisation is normal.
What is examples of environmental generalised hard tissue defect ?
Fluorosis
MIH
How can fluorosis be treated ?
Microabrasion.
Composite veneers.
Vital bleaching.
What causes fluorosis ?
Over-exposure to fluoride.
What might cause MIH ?
Childhood illness - liver or kidney failure.
What are examples of pre-natal conditions which can lead to generalised environmental enamel defects ?
Rubella.
Congenital syphilis.
Cardiac and kidney disease of mother.
What are examples of neo-natal conditions which can lead to generalised environmental enamel defects ?
Prematurity.
Meningitis.
What are examples of post-natal conditions which can lead to generalised environmental enamel defects ?
Otitis media.
Measles.
Chickenpox.
TB.
Pneumonia.
Deficiency of Vit A, C and D.
Heart disease.
What is the timeline of post-natal period ?
8 weeks to 2 years.
What is the timeline of neo-natal period ?
0-8 weeks.
What type of genetic condition is amelogenesis imperfeca ?
Familial inheritance.
Autosomal dominant, recessive and x-linked.
Define hypoplastic type of amelogenesis imperfecta.
Enamel crystals do not grow to correct length.
Define hypomineralised type of amelogenesis imperfecta.
Crystallites fail to grow in thickness and width.
Define hypomaturational type of amelogenesis imperfecta.
Enamel crystal grow incompletely in thickness or width but to normal length with incomplete maturation.
What are the main consequences of amelogenesis imperfecta ?
Sensitivity.
Caries/acid susceptibility.
Poor aesthetics.
Poor OH.
Delayed eruption.
Anterior OB malocclusion.
What are some of the tx options for patients with amelogenesis imperfecta ?
Preventative therapy.
Composite veneers.
Fissure sealants.
Metal onlays.
SSC.
Orthodontics.
Name examples of systemic disorders which are associated with enamel defects (not amelogenesis imperfecta).
Down syndrome.
Prader-Willi.
Porphyria.
Pseudohypoparathyroidism.
What is MIH ?
Developmental condition related to disruption of enamel formation during third trimester and first year of life. Qualitative defect of enamel affecting FPMs and incisors.
Causes unsymmetrical half white/yellow/brown lesions on teeth.
MIH - when is the enamel matrix of FPMs complete by ?
1 year old.
MIH - when is the enamel matrix of permanent incisors complete by ?
2 years old.
What are the characteristics of enamel formation and mineralisation of a tooth affected by MIH ?
Normal amount of enamel and tooth shape.
Reduced mineralisation.
MIH - what phases of tooth development are affected ?
Secretory phase is unaffected.
Amelogenesis is affected i.e. abnormal mineralisation phase.
What are the potential causes of MIH ?
Birth trauma.
Childhood illness in first year of life.
Mother illness in final trimester.
Medications taken in first year of life.
Socioeconomic status.
Prolonged breastfeeding.
What are the dental consequences of MIH ?
Accelerated toothwear, caries formation.
Sensitivity.
Aesthetics.
Problems with dental material bonding.
For FPMs affected by MIH, what are the treatment options ?
SS crown placement. - where severe lesions.
XLA at bifurcation calcification of SPMs - where severe lesions.
Composite restoration or GIC restoration - where mild/localised lesions.
Topical fluoride application - where mild.
For permanent incisors affected by MIH, what are the treatment options ?
Acid pumice microabrasion - localised lesions.
Resin infiltration - localised lesions.
External bleaching.
Localised composite restorations.
Composite/porcelain veneers after 20 years old.
