For a patient missing teeth #17, #18, #19 (left lower) and #30, #31, #32 (right lower), where should rest seats be placed on a Kennedy Class I removable partial denture (RPD)?

This is a Kennedy Class I (bilateral distal extension) situation in the mandible. For distal extension RPDs, rest seats should be placed on the MESIAL aspect of the abutment teeth adjacent to the edentulous spaces (mesial rests on #20 and #29). Mesial rests on distal extension bases transmit occlusal forces toward the remaining teeth rather than tipping the abutment distally, reducing leverage on the abutment teeth. Additionally, mesial rests create a more favorable fulcrum line and reduce rotational displacement of the base. Distal rests on distal extension abutments would increase tipping forces on the abutment teeth.