The Epidemiology, Aetiology, and Histopathology of Developmental Enamel Defects in Human Teeth
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The prevalence of developmental enamel defects in t11 permanent
dentition was investigated in a sample of 2923 East London schoolchildren
aged 5 to 15 years. Enamel discolourations and hypoplasias
were identified using well defined criteria.
Two-thirds of the children had at least one tooth with- an enamel
defect. In the group of 1518 children with 24-28 erupted permanent
teeth, 68 per cent had enamel defects with. a mean of 3.6 per child.
The upper central Incisors and first molars had the highest prevalence
of enamel defects. In these teeth., the proportion of defects decreased
with.. age. The majority of defects were discolourations; 67 per cent
of children..with a "complete" -permanent dentition had discolouration
defects whereas only iS. per cent had enamel bypoplasia.
The aetiology of defects-found in children with. two or more
hypoplastic teeth was investigated in a family study. Four of the
101 index cases had amelogenesis imperfecta and 18 had chronological
hypoplasia caused by systemic diseases. The defects in a further 18
subjects had a probable systemic aetiology. Bilateral hypoplasia
of the lower incisors was found in 22 subjects and a multifactoria].
mode of inheritance was postulated for this condition. For one third
of the index cases no cause could be found for their hypoplasia.
A histological study. complemented thesurveys by describing
structural characteristics of different types of enamel defects.
The investigation highlighted a number of differences between enamel
defects caused by systemic upsets and those caused by genetic factors.
An archaelogical. study assessedthe prevalence-of enamel
h-ypoplasia in a cällection of early British skulls. Thirty-seven
per cent had a number of hypoplastic teeth. There were few severe cases of hypoplasia; the most common type of defect being shallow
horizontal grooves. The many teeth with shallow defects suggested
periodic disturbances in enamel formation between 2 and 6 years of
age.
This thesis has provided further information about the complex
nature of enamel defects. The different aspects of enamel defects
which have been investigated have contributed to a greater understanding
of their prevalence, aetiology and histology.
Authors
Smith, Joyce MaryCollections
- Theses [4403]