At what point in removable partial denture treatment are the height of contour and the position of the retentive clasp terminal determined?

Correct answer: B. At the surveying appointment on the diagnostic cast, before the master impression

• A. Framework insertion is far too late; the metal is finished.
• B. CORRECT. SURVEYING the DIAGNOSTIC cast is the design step, and it comes before anything irreversible. The surveyor establishes the path of insertion, marks the SURVEY LINE (height of contour) on each abutment, and an undercut gauge measures the depth available for the retentive clasp terminal. Only once this is decided can you know which teeth need guide planes, rest seats, or recontouring — mouth preparations that must be completed before the master impression is taken.
• C. By try-in the framework is already cast. Clasp position cannot be redesigned at that point without remaking the framework.
• D. Tooth arrangement follows framework fabrication and has no bearing on clasp design.

Note: Source keyed 'before the preliminary impression,' which is not quite right — the diagnostic cast comes FROM the preliminary impression. The accurate answer is: survey the diagnostic cast after the preliminary impression, and before the master/final impression. Worth correcting in the group file.