Dens Evaginatus

Leong ’ s premolar
Dens evaginatus is the result of an outpouching of the enamel organ. The resultant enamel-covered tubercle usually occurs in or near the middle of the occlusal surface of a premolar or occasionally a molar.
Lateral incisors are most commonly involved, whereas canines are rarely affected.
The frequency of occurrence of dens evaginatus is highest in Asians and Native Americans.

Clinically, dens evaginatus appears as a tubercle of enamel on the occlusal surface of the affected tooth.
A hard, polyplike protuberance predominantly exists in the central groove or lingual ridge of a buccal cusp of posterior teeth and in the cingulum fossa of anterior teeth.
Dens evaginatus may occur bilaterally and usually in the mandible.
The tubercle often has a dentin core, and a very slender pulp horn frequently extends into the evagination.

After the tubercle is worn down by the opposing teeth, it appears as a small circular facet with a small black pit in the center.
Wear, fracture, or indiscriminate surgical removal of this tubercle may precipitate a pulpal infection because of the exposure of the pulp horn.
In rare cases a microscopic direct communication may occur between the pulp and the oral cavity through this tubercle. In these instances the pulp may become infected shortly after eruption.

The radiographic image shows an extension of a dentin tubercle on the occlusal surface unless the tubercle is already worn down.
The dentin core is usually covered with opaque enamel.
A fine pulp horn may extend into the tubercle, but this may not be visible radiographically.
If the tubercle has been worn to the point of pulpal exposure or has fractured, pulpal necrosis may result.
This is indicated by an open apical foramen and periapical radiolucency.
Multiple root formation is often associated with dens evaginatus, especially in mandibular premolars.

If the tubercle causes any occlusal interference or shows evidence of marked abrasion, it should probably be removed under aseptic conditions and the pulp capped, if necessary.
Such a precaution may preclude pulpal exposure and infection as the result of accidental fracture or advanced abrasion.