Which tooth anomaly is described as evagination of the enamel epithelium and focal hyperplasia of pulp mesenchyme?

The anomaly described as evagination of the enamel epithelium and focal hyperplasia of pulp mesenchyme is indeed dense evaginatus. This condition occurs when there is an abnormal proliferation of the enamel organ, leading to the development of an accessory cusp or projection of enamel on the tooth. It is characterized by the presence of additional tissue that contains enamel, dentin, and possibly pulpal tissue, suggesting a direct connection between the enamel and the underlying pulp mesenchyme.

Dense evaginatus can lead to complications such as malocclusion or dental caries due to the atypical shape of the tooth, which may create areas difficult to clean. Understanding this anomaly is crucial for dental professionals in diagnosing and managing such cases, especially during preventive care and restorative processes.

Other options describe different anomalies: fusion refers to the joining of two teeth, gemination involves the incomplete formation of a single tooth, resulting in a bifid appearance, and concrescence describes the fusion of roots of teeth through cementum only. These distinctions highlight the unique aspects of each anomaly, clarifying why dense evaginatus is the correct choice in relation to the given description.