Rotation of a distal extension base around longitudinal axis is resisted by: (A) Rigidity of major connector, (B) Rigidity of minor connector, (C) Both of the above, (D) None of the above
Answer is C. A second movement is rotation about a longitudinal axis as the distal extension base moves in a rotary direction about the residual ridge. This movement is resisted primarily by the rigidity of the major and minor connectors and their ability to resist torque.