Which category of extracoronal direct retainer comes from the occlusal aspect of the tooth and then goes cervical to engage the undercut?

Which category of extracoronal direct retainer comes from the occlusal aspect of the tooth and then goes cervical to engage the undercut?

• A. Suprabulge
• B. Infrabulge
• C. Intracoronal
• D. Embrasure clasp

Answer: (A)

The question tests how extracoronal direct retainers are categorized by where the retentive part emerges on the tooth relative to its height of contour. A suprabulge retainer starts on the occlusal (or incisal) aspect and then extends cervically to engage an undercut below the height of contour. That path—originating from the occlusal aspect and moving down toward the gingival area to grab the undercut—is exactly what defines suprabulge. The other options don’t fit this description: a retainer that starts below the height of contour engages the undercut from a gingival direction (infrabulge), a component that remains inside the crown is intracoronal, and an embrasure clasp uses the space between adjacent teeth rather than starting from the occlusal aspect of the tooth.

The question tests how extracoronal direct retainers are categorized by where the retentive part emerges on the tooth relative to its height of contour. A suprabulge retainer starts on the occlusal (or incisal) aspect and then extends cervically to engage an undercut below the height of contour. That path—originating from the occlusal aspect and moving down toward the gingival area to grab the undercut—is exactly what defines suprabulge.

The other options don’t fit this description: a retainer that starts below the height of contour engages the undercut from a gingival direction (infrabulge), a component that remains inside the crown is intracoronal, and an embrasure clasp uses the space between adjacent teeth rather than starting from the occlusal aspect of the tooth.