Amelogenesis imperfecta

Date: 2015-10-07; view: 710.

Amelogenesis imperfecta is the term applied to generalized enamel defects affecting all (or predominantly all) of the teeth of both the primary and permanent dentitions. It is of genomic origin and thus there may be a family history of similar defects in other family members. Although the term strictly relates to enamel defects only, in some patients there may be subtle or substantial changes in other dentaltissues and craniofacial structures, or the condition may involve more widespread abnormalities as a part of a syndrome. Dentally, there may be failures of eruption with resorption of the unerupted teeth. A case may be made for regular radiographic review of these patients. Amelogenesis imperfecta is seen in single gene mutations with autosomal dominant, autosomal recessive, and X-linked patterns of inheritance. Apparently sporadic cases are also seen - it is not clear whether these represent new mutations, or whether these will then be passed on to future offspring. AI is relatively uncommon, but there are marked population differences in prevalence. In parts of Sweden the condition is relatively common (one in approximately 700 of the population). In one study in the United States the prevalence was found to be approximately 1 in 14,000.

The classification of amelogenesis imperfecta has traditionally been based on the phenotype - the clinical appearance. Following this system, patients are allocated according to the perceived defect - hypoplasia, hypocalcification, or hypomaturation. Some classifications have an additional category of hypomaturation-hypoplasia with taurodontism to reflect the fact that some families show a combination of thin and/or poorly mineralized enamel as well as taurodontism (the term taurodontism is used to describe molar teeth in which the body of the tooth is enlarged vertically at the expense of the roots).