36 Multiple missing and abnormally shaped teeth
As you are speaking to Ellen’s mother you notice that she has a missing upper right lateral incisor and the canine tooth is prominent. She confirms your question that not only has she got a missing tooth, but her brother and her nephew (son of her brother) have either missing or very small upper lateral incisors.
There are a significant number of syndromes of the head and neck that manifest with missing teeth. Can you name some?
Ectodermal dysplasia describes a group of inherited disorders involving ectodermally derived structures, i.e. hair, teeth, nails, skin and sweat glands. The most common form is the hypohidrotic X-linked form. The usual presentation is a male child with:
Down syndrome affects 1 in 700 births and is commoner in offspring of older mothers, and is a result of chromosomal translocation. Apart from the morphological features characteristic of the syndrome, there is commonly delayed eruption and generalized microdontia as well as hypodontia of some teeth.
The diagnosis and management of all dental anomalies is extremely important and should not be delayed. Genetic consultation is often desirable to not only confirm the diagnosis but also to help parents understand the risk of future offspring and generations being affected. Conversely, geneticists may require help from paediatric dentists to clarify a diagnosis.