Imagine being able to bring your shoulders together in front of your chest because your collarbones are severely underdeveloped or, in some cases, completely absent.
This is one of the most recognisable features of a rare genetic condition called cleidocranial dysplasia. But the condition does not just affect the bones. It can also have a significant effect on the development and eruption of teeth.
When Bone and Tooth Development Are Affected
People with cleidocranial dysplasia can have underdeveloped or absent collarbones, delayed closure of the skull bones and shorter stature. The condition is caused by changes in the RUNX2 gene, which plays an important role in bone and tooth development.
The dental features can be quite striking. Permanent teeth may erupt much later than usual, baby teeth may remain in place, and multiple extra teeth can develop. As a result, a person may have numerous unerupted or impacted teeth, severe crowding and problems with tooth alignment.
The Unusual Dental Features
What makes the dental presentation particularly interesting is the sheer number of teeth that may remain unerupted. In some cases, a patient can have dozens of unerupted permanent and supernumerary teeth visible on an X-ray.
Treatment can be complex and may involve removing retained baby teeth and supernumerary teeth, surgically exposing permanent teeth and using orthodontic treatment to guide them into the mouth. Because of the number of teeth involved, treatment may take several years.
Cleidocranial dysplasia is a good reminder that tooth development is closely connected to the development of the rest of the body.
Have you ever seen a dental X-ray that looked this unusual?
What other genetic conditions have interesting dental manifestations?
MBH/PS