_____ prevent the movement of the clasp arm toward the cervical.

_____ prevent the movement of the clasp arm toward the cervical.

• A. Reciprocal arm
• B. Guiding plate
• C. Occlusal rest
• D. Clasp terminus

Answer: (C)

The key idea is that an occlusal rest provides a solid vertical support on the abutment tooth and acts as a fulcrum for the direct retainer. When forces try to move the clasp arm toward the cervical (gingival) direction, the rest resists that rotation and tipping, distributing the load through the tooth and surrounding structures. This keeps the clasp arm from migrating apically toward the cervix and helps maintain the proper path and seating of the clasp. The other parts play stabilizing or guiding roles but do not specifically prevent cervical movement: the reciprocal arm helps balance forces on the tooth, the guiding plate directs the movement of the clasp to avoid unfavorable tipping, and the clasp terminus is the retentive end that engages undercut, not a limiter to cervical displacement.

The key idea is that an occlusal rest provides a solid vertical support on the abutment tooth and acts as a fulcrum for the direct retainer. When forces try to move the clasp arm toward the cervical (gingival) direction, the rest resists that rotation and tipping, distributing the load through the tooth and surrounding structures. This keeps the clasp arm from migrating apically toward the cervix and helps maintain the proper path and seating of the clasp.

The other parts play stabilizing or guiding roles but do not specifically prevent cervical movement: the reciprocal arm helps balance forces on the tooth, the guiding plate directs the movement of the clasp to avoid unfavorable tipping, and the clasp terminus is the retentive end that engages undercut, not a limiter to cervical displacement.