Primary failure of eruption: a possible cause of posterior open-bite.

Failure of posterior teeth to erupt fully into occlusal contact produces a lateral open-bite. These problems usually are attributed to a mechanical interference with the eruptive process, either ankylosis or some soft-tissue interference. In some patients, lateral open-bite is due to a disturbance of the eruption mechanism itself so that nonankylosed teeth cease to erupt. Influences on the eruption of teeth are reviewed, and possible causes of "primary failure of eruption" are discussed. The limitations of treatment for patients with eruption failure are described and illustrated by case reports.