Where do the terminus points of the retentive arm lie?

Where do the terminus points of the retentive arm lie?

• A. Occlusal
• B. Gingival
• C. Apical
• D. Cervical

Answer: (A)

The suction to retain an RPD comes from how a retentive arm engages an undercut on the tooth. The end of that arm, its terminus, should be oriented toward the occlusal (toward the biting surface) aspect of the tooth. This positioning makes the denture removal path cause the retentive arm to ride over the height of contour and into the undercut, increasing friction and keeping the clasp engaged. If the terminus were toward the gingival or apical direction, withdrawal forces could pry the clasp away more easily, stressing the soft tissues and reducing retention. So, the terminus points lie toward the occlusal direction.

The suction to retain an RPD comes from how a retentive arm engages an undercut on the tooth. The end of that arm, its terminus, should be oriented toward the occlusal (toward the biting surface) aspect of the tooth. This positioning makes the denture removal path cause the retentive arm to ride over the height of contour and into the undercut, increasing friction and keeping the clasp engaged. If the terminus were toward the gingival or apical direction, withdrawal forces could pry the clasp away more easily, stressing the soft tissues and reducing retention. So, the terminus points lie toward the occlusal direction.