Primary failure of eruption in the permanent dentition of siblings.

Primary failure of eruption is a condition where there is eruption failure in the permanent dentition with no obvious mechanical cause. It has previously been reported in the literature as a cause of posterior openbite, with a varying degree of familial inheritance. This case report describes two sisters that experienced eruption failure in the permanent dentition, most notably of the first and second molars, with greater severity in the younger sister. Teeth were exposed in both patients and orthodontic traction was applied with little or no success. The report provides further evidence of the genetic contribution to the aetiology of this condition and also highlights the problems in attempting treatment, including exposing to the oral environment teeth that are infra-occluded and difficult to clean effectively.