For a class I RPD, if the distal abutments are teeth #20 and #24, where should the indirect retention be located?

In a class I removable partial denture (RPD) situation, indirect retention is critical for maintaining the stability and prevention of displacement of the prosthesis during function. It is specifically positioned in relation to the primary abutment teeth.

When the distal abutments are located on teeth #20 (mandibular left first molar) and #24 (mandibular right first premolar), the indirect retention should be established at a site that is anterior to these abutments in order to counteract the potential tipping force that might occur during function.

The appropriate placement of indirect retainers is usually on the teeth adjacent and anterior to the distal abutments. In this case, teeth #22 and #27 serve as effective locations for the indirect retention. Tooth #22, being a canine, provides significant resistance to lever forces, and tooth #27 is also positioned favorably to enhance the overall stability of the prosthesis.

Selecting teeth #21 and #26 instead would not provide the same functionality as they do not position the retainers in the optimal relationship to counterbalance the forces acting on the abutment teeth. Thus, the answer identifies the correct positioning of indirect retention, reinforcing the design and stability of the class I