Amelogenesis imperfecta

Amelogenesis imperfecta (AI) is a group of congenital disorders, involving the abnormal formation of tooth enamel, the external layer of the crown of teeth. Amelogenesis imperfecta can be unrelated to any systemic or generalized conditions or can be part of a syndromic condition. Healthy, fully formed enamel is approximately 96% mineral by weight and forms over months to years in humans, depending upon the tooth in question.

Amelogenesis imperfecta typically occurs as a result of mutations in the genes that encode proteins directly involved in tooth enamel formation, although there are some rare exceptions. Knowledge of the specific functions of some of the proteins encoded by these genes is incomplete. In short, pathogenic variants in these genes prevent the amelogenesis developing as it should, leading to amelogenesis imperfecta.

People with amelogenesis imperfecta may have teeth with thin or even absent enamel or enamel which is soft or brittle. Their remaining tooth enamel or tooth surface may be of abnormal color, for example yellow, brown or opaque white, and may be pitted. Affected teeth have a higher risk for dental cavities and are likely to be hypersensitive to temperature changes. Teeth may exhibit rapid wear post-eruption and may have excessive dental plaque deposition due to pain upon brushing.