Prosthodontics & Occlusion · single question
Which Kennedy classification requires an indirect retainer?
Show answer and explanation
Correct answer: A. Kennedy Class I (bilateral posterior edentulous areas)
- A. Correct. Kennedy Class I (and Class II) RPDs have distal extension bases that are not bounded by teeth posteriorly. These distal extensions tend to rotate around the fulcrum line when anterior occlusal forces are applied, lifting the base away from tissue. An indirect retainer, placed anterior to the fulcrum line, prevents this rotation.
- B. Kennedy Class III is tooth-supported (bounded by teeth on both sides); it does not require an indirect retainer because there is no rotation problem.
- C. Class III modifications are still tooth-supported and generally do not require indirect retainers.
- D. Kennedy Class IV (anterior crossing midline) may require an indirect retainer for long spans, but Class I definitively requires it.
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